Sourdough and the process for its production

Abstract

Sourdough and the process for its production

Description

Sourdough and its production process The present invention relates to leavening agents and their production processes. Sourdough is a traditional product obtained through the natural acidifying fermentation of flour and water. The resulting sourdough contains a living and metabolically active microflora composed primarily of lactic acid bacteria and yeasts. Used in breadmaking, its function is to ensure the dough rises and acidifies. In France, sourdough is defined in Article 4 of Decree No. 93-1074 of September 13, 1993, along with the expected characteristics of sourdough bread. Sourdough is known for the typical aroma and smell it gives to bread, marked by tangy notes. This acidifying function of sourdough also affects all organoleptic attributes (a fattier crumb texture, irregular air pockets, a thicker and crispier crust), improves bread preservation, and promotes the bioavailability of minerals (phytate degradation in an acidic environment). Sourdough is clearly distinct from baker's yeast, which is produced through the selection and multiplication of yeast strains, primarily of the genus Saccharomyces, whose essential function is to leaven all types of dough. Each yeast strain is specifically selected for precise applications (regular, sweet, sour, chilled, frozen dough, etc.). Baker's yeast cannot be used to make sourdough bread because it does not produce the necessary organic acids. In contrast, sourdough has a lower leavening activity than yeast, but its lactic acid bacteria produce several acids, notably the acetic acid of sourdough bread. Therefore, breadmaking with sourdough requires longer rising times than with baker's yeast and inevitably leads to the acidification of the dough.The use of sourdough is therefore generally unsuitable, and replaced by baker's yeast, for example to make ordinary bread or sweet doughs such as brioche, where the rising time of the dough is short and the final products must not be acidic. A direct bread-making process is one in which the dough fermentation is never stopped by refrigeration between the start of kneading and the end of baking. Delayed bread-making processes, on the other hand, include a refrigeration phase to stop fermentation, which allows for easier adjustment of the baker's workflow. A short bread-making process involves dough fermentation times of less than 6 hours, while a long process requires dough fermentation times of more than 6 hours. The invention relates to a sourdough starter and its preparation method capable of raising all types of dough without the addition of yeast, and, in an improvement, also of fermenting sourdough bread dough. The sourdough starters obtained according to the invention comply with French regulations and are distinguished by their wide range of uses without the need for the addition of baker's yeast. They can be used in both direct or delayed, short or long bread-making processes, promoting dough rising without introducing acidity into the final product, or for making sourdough bread that complies with French regulations, with a pH < 4.3 and an acetate level > 900 ppm (for the sourdough starter improved according to the invention). Commercial sourdough starters currently on the market do not offer such flexibility of use. The starters available are not efficient enough to leaven regular or sweet doughs using short baking processes. Furthermore, for sourdough bread applications according to French regulations, current commercial sourdough starters contain high levels of organic acids, which significantly slows the metabolic activity of the microorganisms they contain. These starters thus provide a large quantity of the required acids, but have less fermentative activity during breadmaking, both in terms of acidification and dough rising; they therefore generally require the addition of baker's yeast. The improved sourdough starter according to the invention is remarkable because it is relatively low in acidity but possesses a metabolically active microflora that produces organic acids endogenously during breadmaking and causes the dough to rise without the addition of yeast. In terms of the production process, the present invention describes a completely natural process based on spontaneous fermentation of microorganisms present on fermentable substrates and directed by physical parameters, unlike the process of manufacturing baker's yeast which requires the addition of nutrients and chemicals such as ammonium phosphate and antifoaming agents or unlike other processes of obtaining sourdough starters inoculated with selected microbial starters and cultivated on synthetic nutrient media. The invention relates to a sourdough starter that allows the production, without the addition of yeast, of all types of bread, brioche, panettone, and all leavened doughs, including laminated doughs, that require a fermentation phase. Following further improvements, it also allows the production of sourdough bread with a smaller quantity of starter than previous sourdough starters. In the process of producing a sourdough starter according to the invention, successively: a) A fermentable matrix is ​​cleaned with water by completely immersing it in water and draining it until the water that drains away is clear, so as to obtain a cleaned matrix, or one still containing 200 g to 1.5 kg of residual water per 2 kg of matrix which is incubated, or one containing less, and in the latter case, the cleaned matrix is ​​immersed in water between 10 and 35°C at a ratio of 1 to 20 kg of water per 2 kg of matrix which is incubated, the incubation being carried out between 10 and 35°C until bubbles appear on the surface of the liquid (called juice), so as to obtain an incubated matrix, b) the juice is separated from the rest of the incubated matrix, c) The juice is mixed with the substrate to obtain a mixture having a dry matter content by weight between 15 and 60% and is left to ferment for 12 to 72 h between 9 and 30°C to obtain a medium and d) In the middle of the substrate and water at a temperature between 10 and 35°C, a quantity of substrate and water representing 25 to 75% of the total volume is added to obtain the product. Fermentation is then allowed at a temperature between 9 and 30°C with the addition of air, oxygen, or a gas mixture containing oxygen. Food-grade air can be injected using any system that allows air to be diffused at the bottom of the tank at a flow rate ranging from 0.01 to 10 m³ / h / kg of product, preferably between 0.01 and 1 m³ / h / kg of product, to obtain sourdough starter. It is crucial to only insufflate air or oxygen at stage d). Preferably, stage c) and stage d) are repeated several times, especially three times. Preferably, stage d) can be followed by stage e), in which stage d) is repeated, but with a dry matter content of 30 to 60% by weight. Preferably, stage e) is repeated at least three times. A fermentable matrix is ​​a material that naturally contains microbial flora, including lactic acid bacteria and yeasts. This matrix can be, in particular: - cereals (soft wheat, durum wheat, rye for example), pseudo-cereals (buckwheat, quinoa for example), legumes; and in all their forms (whole dried or sprouted seeds, flours, semolina and other fractions (brans, germs for example)), - all fruits (apple, pear, banana, grape for example) and dried fruits, whole or parts (skin, flesh, pulp, seeds) fresh and processed (dried, juice, fermented musts), - vine wood (shoots, chips...), - cabbage, hops, malts (wheat, barley for example), honey etc. The substrate can be flour or any other fraction of cereal or pseudo-cereal or legume. The process allows obtaining a sourdough starter with a pH between 3 and 6, a total titratable acidity of less than 20, an acetic acid level of less than 2,000 ppm, a lactic acid level of less than 8,000 ppm, a yeast level in log(fcu) / g between 7 and 9, a lactic bacteria level in log(fcu) / g between 8 and 10 and which, used in baking in a bread preparation process according to the following successive stages: 1275 g of water, 2000 g of flour and 200 g of sourdough starter are introduced in order into a spiral mixer with rotating arms and bowl. The dough is kneaded for 5 minutes at a speed of 70 rpm for the mixer arm and 10 rpm for the mixing bowl. 40 g of salt is added to the mixer. The dough is then kneaded for 3 minutes at a speed of 160 rpm for the mixer arm and 18 rpm for the mixing bowl, until the dough reaches a temperature of 25-27°C after kneading. The dough is then proofed for 1 hour in a fermentation chamber at 25°C and 75% humidity.The dough is manually divided into 350g pieces, which are then pre-shaped into oval balls. These are left to rest for 20 minutes in a fermentation chamber at 25°C and 75% humidity. They are then shaped into a bâtard or baguette form with the seam sealed. A 4-5 hour proofing in a fermentation chamber at 25°C and 75% humidity is carried out, followed by baking for 20 minutes at 240°C with steam injection at the time of baking. This results in a dough before baking with a rise measurement at 5 hours in cm greater than 2 and at 6 hours greater than 2.8. This dough produces a loaf with a mass volume at least equal to 3cm3 / g and, preferably, an acetate level greater than 900 ppm and a pH greater than 4.3 in a sourdough bread making process. To make ordinary bread, 5 to 40%, preferably 10 to 15%, of sourdough starter is used in relation to the weight of the flour. To make sourdough bread, 0.5 to 5%, preferably 1 to 3%, of sourdough starter is used in relation to the weight of the flour. The pH and total titratable acidity (TTA) are measured from samples of fresh sourdough starter. Ten grams of sourdough starter are mixed with 90 ml of distilled water using a magnetic stirrer for 5 min. The pH is measured on this mixture, under stirring, with a Mettler Toledo (brand name) G20 pH meter. The TTA (total titratable acidity) is measured under stirring by titration with 0.1 mol / L sodium hydroxide (mol per liter) until a pH of 8.5 is reached. TTA is defined as the volume (in ml) of 0.1 mol / L NaOH solution required to reach a pH of 8.5. The dry matter (DM) content of sourdough starters is measured using an infrared method with a Radwag (trademark) MAC 50 / 1 halogen dryer. Sourdough samples are fresh. Measurements are taken in triplicate on 2.0 to 0.1 g of starter and then averaged. The analysis program applies a temperature of 130°C until the change in the weight value is ≤ 1 mg in 25 s. The values ​​are expressed as a percentage of DM in the starter. Lactic acid and acetic acid levels are measured enzymatically using the ENZYTECTM D- / L-Lactic acid and ENZYTECTM acetic acid kits (Scil Diagnostic GmbH, Germany). Sourdough samples are fresh, homogenized, and diluted 1:100, then centrifuged at 12,000 g for 20 minutes. The supernatant is collected. Analysis is performed on this sample. Results are expressed in ppm (parts per million = mg / kg). The yeast content was determined according to the AFNOR NF V08-059 reference standard, routine method, as follows: Inoculation is performed on the surface of chloramphenicol glucose agar (Biokar (brand name)) previously poured into Petri dishes with a determined quantity of stock suspension and / or decimal dilutions of the sample. The count is performed after incubating the dishes aerobically at 25 ± 1°C for 5 days. The result is expressed as the decimal logarithm of colony-forming units per gram of starter culture (log(CFU) / g). The mesophilic lactic acid bacteria count was determined according to the reference standard NF ISO 15214 (classification index V 08-030), reference method, as follows: Inoculation is performed on the surface of MRS agar (Biokar (trademark)) previously poured into Petri dishes with a determined quantity of stock suspension and / or decimal dilutions of the sample. The count is carried out after incubation of the dishes under anaerobic conditions at 30°C for 72 to 120 hours. The result is expressed as the decimal logarithm of colony-forming units per gram of starter culture (log(CFU) / g). The rising times at 5 and 6 hours were determined using a Böhler riser measuring device consisting of a graduated cylinder marked from 1 to 7, in 0.2 mm increments, conforming to standard NF X03-716. At the end of kneading, 20 g of bread dough were taken and placed in the Böhler measuring device to create a flat surface. The rise volume was recorded every hour until 6 hours of rising. The volume of the loaves (in cm³) is determined using a Chopin volumetric trowel. The weight of the loaves is measured using a Mettler Toledo VIPER SW 6 balance. The specific volume is the ratio between the volume and the weight of the loaf, and is expressed in cm³ / g. The sourdough starter, once produced, can be used as is, or stored in positive or negative cold, or dehydrated by any process which allows the water to be eliminated while keeping the microorganisms alive such as freeze-drying or any other technique where it can be maintained as many times as necessary, in order to keep the ecosystem in an active state and thus propagate the fermentation and preserve the characteristics of the sourdough starter. Sourdough can be used to produce all doughs requiring fermentation, such as bread and all its variations: country bread, multigrain bread, traditional bread, corn bread, baguette, etc., sandwich bread, buns and related products, pastries, brioches, croissants, panettone and their variations, and pizza dough. These doughs can include, in particular: -leavened dough or kneaded dough: brioche dough, bread dough, savarin pastry, "Baba's dough" Panettone -flaky leavened doughs: croissant dough or rolled dough, Danish puff pastry, -beaten pasta: Madeleine dough, Genoise-style pastry, Genoa bread dough, cookie dough, cake batter, -others: doughnut dough, pancake batter, The rolled dough is the basis of cakes. The sourdough bread (meeting the 1993 bread decree) obtained has a typical fermented taste, it has a thick, golden and crispy crust. Regular bread (that is, bread not made using a sourdough recipe) has a thin, golden crust, is crisp, and has a mild flavor. The sourdough starter according to the invention represents 5 to 40%, and preferably 10 to 15%, of the weight of the flour used to make regular bread. For sourdough bread, the improved sourdough starter according to the invention represents 0.5 to 5%, and preferably 1 to 3%, of the weight of the low-ash flour (substrate) used to make sourdough bread. The brioche also has a thin, golden and shiny crust, a light and melting crumb, milky aromas of butter and cream, without an acidic taste. Sourdough also makes it possible to produce panettone that complies with Italian legislation on this product and has the typical sensory and organoleptic characteristics of this product. The process according to the invention can be carried out in the following steps: Step 1: Clean the fermentable matrix with water (any type of water) at a temperature between 10 and 30°C. Cleaning can be carried out: 1 / by placing the fermentable matrix in a container, then immersing it in water (completely covering the matrix with water), then draining it using a sieve, skimmer or strainer (inverting the container so as to empty the water, while recovering the fermentable matrix) or 2 / by placing the fermentable matrix in a perforated container (strainer, sieve, skimmer, etc.) or holding it in your hand, then running water over the matrix (any type of water, any flow rate) so that the water rinses the matrix, then flows away immediately. The objective of this step is to eliminate impurities from the fermentable matrix. The cleaning operation must be repeated until clear (translucent) rinsing water is obtained, that is to say, the water that flows out during draining (case 1) or post-rinsing (case 2) must be identical to the clean water used for cleaning. Step 2: Drain the cleaned matrix by placing it in a perforated container to allow the water to drain naturally or by squeezing it with any system that allows the water to separate from the matrix. Step 3: Immerse the drained fermentable matrix in water (any type of water) at a temperature between 10 and 35°C. Add water so as to immerse the matrix to a minimum of half the height / volume it occupies in the container and at a maximum, preferably up to ten times the quantity of matrix used (example: for 2 kg of matrix, you can add up to 20 kg of water). It is possible to omit adding water at this stage. Following the draining in stage 2, the matrix is ​​placed in a container, and then we proceed to stage 4. The residual water absorbed by the grains is sufficient to initiate a fermentation process. The amount of residual water should be between 200 g and 1.5 kg (beyond this, the process is considered immersion, as in the case above). Step 4: Incubate this cleaned matrix between 15 and 35°C for 18 to 168 h, preferably between 20 and 30°C and better at 25°C, preferably from 24 h to 5 days and better from 48 to 72 h. At the end of incubation, if the incubated matrix is ​​submerged, check for the presence of several bubbles on the surface of the liquid. This indicates that the fermentation of the fermentable material is effective and that the liquid (called juice) contains a microflora composed at a minimum of yeasts and lactic acid bacteria. If the incubated matrix has not been immersed, proceed directly to step 5. Step 5: Recover only the liquid phase (called juice) using any equipment that allows the liquid part to be separated from the solid part of a matrix. For example, to separate the liquid phase from the solid phase (and recover the two phases separately), it is possible to filter with a porosity greater than 100 µm (in this case), to centrifuge, to press, or to decant. It is possible to proceed directly from step 5 to step 9. However, it is preferable to complete the intermediate steps 6 through 8, as they allow for the establishment of a stable ecosystem composed of lactic acid bacteria and yeasts. If proceeding directly to step 9, it is recommended to apply moderate aeration to avoid harming the lactic acid flora, which is composed of anaerobic bacteria and could disrupt the ecosystem. Step 6: Place the juice in a container (any type of container meeting food standards) of any type of shape, size and material. Next, mix this juice with the substrate. The substrate can be flour or any other fraction of cereals, pseudo-cereals, or legumes. The mixing can be carried out using any means or equipment, manual or mechanical, that produces a homogeneous mixture (homogeneous: the number of agglomerates / aggregates will not exceed 50% by weight of the mixture). The dry matter (DM) content of the mixture should be between 15 and 60% by weight, preferably between 40 and 50%, and ideally between 42 and 46%. Then, let it ferment for 12 to 72 hours, preferably between 18 and 48 hours and better between 22 and 28 hours, between 9 and 30°C, preferably between 15 and 27°C and better between 23 and 26°C, without stirring or with stirring (any type of stirring system / equipment, continuous or discontinuous stirring, at a low speed between 30 and 150 revolutions per minute to prevent decantation). Step 7: Place the mixture obtained at the end of step 6 into a container (any type of container meeting food standards) of any type of shape, size and material. Replenish the growing medium by adding substrate and water (any type of water) at a temperature between 10 and 35°C, so that this addition (substrate + water) represents between 25 and 75%, preferably between 33 and 60%, and ideally between 33 and 50%, of the final volume. Mixing can be carried out using any means or equipment, manual or mechanical, that produces a homogeneous mixture (homogeneous: the number of clumps / aggregates must not exceed 50% by weight of the mixture). The dry matter content of the final mixture should be between 15 and 60% by weight, preferably between 40 and 50%, and ideally between 42 and 46%. Then, let it ferment for 12 to 168 hours, preferably between 18 and 72 hours and better between 24 and 48 hours, between 9 and 30°C, preferably between 15 and 27°C and better between 23 and 26°C, without stirring or with stirring (any type of stirring system / equipment, continuous or discontinuous stirring, at 30 to 150 revolutions per minute to prevent decantation). Step 8: Same as step 7. Step 9: Place the medium obtained at the end of step 8 into a container (any type of container meeting food standards) of any type of shape, size and material. Replenish the substrate by adding fresh substrate and water (any type of water) at a temperature between 1 and 35°C, preferably between 1 and 15°C, so that this addition (substrate + water) represents between 25 and 75%, preferably between 33 and 66%, and ideally 50% of the final volume. Mixing can be carried out using any means or equipment, manual or mechanical, that produces a homogeneous mixture (homogeneous: the number of clumps / aggregates must not exceed 50% by weight of the mixture). The dry matter content of the final mixture should be between 15 and 60% by weight, preferably between 40 and 50% and better between 42 and 46%. Next, stir the mixture using any type of stirring system / equipment. Stirring can be continuous or intermittent, at any speed, and with the injection of air or oxygen using any type of equipment or technology that allows the injection of air, oxygen, or an oxygen-containing gas mixture. Preferably, air injection is from below. Air (preferably dry and oil-free) can be injected into a sparger at the bottom of the tank at a pressure, for example, of 8.5 bar, and a flow rate varying from 0.01 m3 / h / kg of mixture to 10 m3 / h / kg of mixture depending on its consistency, preferably with a flow rate between 0.01 and 1 m3 / h / kg of mixture. Allow to ferment under these conditions of agitation and aeration and at a temperature between 9 and 30°C, preferably between 9 and 17°C and better between 10 and 15°C, for 12 hours to 10 days, preferably between 3 and 8 days and better between 6 and 8 days. The injection of air or oxygen, as well as the temperature and fermentation time, are regulated so as to obtain, at the end of this stage, preferably a minimum yeast count of 107 cfm / g of product. This method promotes the growth of yeast flora over lactic acid bacteria. Given the specified temperature range, the higher the temperature, the shorter the fermentation time (and vice versa). We can stop at the end of this step (9), however it is preferable to carry out the following steps. Step 10: Place the medium obtained at the end of step 9 into a container (any type of container meeting food standards) of any type of shape, size and material. Replenish the substrate by adding fresh substrate and water (any type of water) at a temperature between 1 and 35°C, preferably between 1 and 15°C, so that this addition (substrate + water) represents between 25 and 75% of the final volume, preferably between 33 and 66%, and ideally 50%. The mixing can be carried out using any means or equipment, manual or mechanical, that allows for obtaining a homogeneous mixture (homogeneous: the number of clumps / aggregates must not exceed 50% by weight of the mixture). The dry matter content of the final mixture should be between 15 and 60% by weight, preferably between 40 and 50% and better between 42 and 46%. Next, stir the medium using any type of stirring system / equipment; the stirring can be continuous or discontinuous, at any speed. Allow to ferment under these conditions of agitation and aeration and at a temperature between 9 and 30°C, preferably between 9 and 17°C and better between 10 and 15°C, for 16 to 72 h, preferably between 36 and 72 h and better for 48 h. Step 11: Same as step 10. The objective of steps 9, 10 and 11 is to promote the development of the yeast flora and, in general, to allow the establishment of the microbial ecosystem and the physico-chemical characteristics of the sourdough, by obtaining the sourdough according to the invention, but not perfected. Step 12: To produce a perfected sourdough starter, suitable for both regular bread and sourdough bread, the preferred values ​​from the preceding steps should be used, and step 12 should be added. This step repeats step 11, except that the dry matter content of the final mixture should be between 30 and 60%, preferably between 40 and 53%, and ideally between 45 and 50%. Step 12 may be repeated at least three times. This repetition is beneficial for producing a perfected sourdough starter. Finally, to produce a perfected sourdough starter, the substrate (flour) should have an ash content >0.75%, preferably between 0.75 and 1% by weight (percentage based on the dry matter of the flour). The ash content is measured by incineration according to standard NF EN ISO 2171 on 5 g + / - 0.1 mg of precisely weighed flour. The result is expressed as a percentage by mass relative to the dry matter. At the end of this step, we obtain the perfected sourdough starter according to the invention. The following examples illustrate the invention. Example 1: 6 kg of wheat grains were weighed in a food-grade PP bucket (PP stands for polypropylene). 30 litres of tap water at 15°C were added, then left to rest for 30 min at room temperature. Washing the wheat grains: The grains, immersed in water, were then rubbed by hand for 10 minutes, after which the water was drained. 30 liters of tap water at 15°C were added again, and the grains were rubbed again by hand (this operation was repeated five times successively). Rinsing the wheat grains: 30 liters of tap water at 25°C are poured over the wheat grains, then the grains are drained by manual pressing through a conical stainless steel sieve. The water is then discarded, while the grains are kept (this operation is repeated fifteen times successively). Final draining of the grains by manual pressing through a conical stainless steel sieve. Only the grains are retained. The 6 kg of washed and drained wheat grains are placed in a food-grade PP bucket. 24 kg of tap water at 25°C are added. The bucket is placed in an oven at 25°C for 67 hours. The preparation is drained by manual pressing through a conical stainless steel sieve in order to separate the liquid phase (juice) from the grains. Only the liquid phase is retained. 13 kg of juice are weighed and introduced into a stainless steel fermenter. 13 kg of wheat flour are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 10 min. The preparation is kept at 25°C for 24 hours. The dry matter content of the fermented preparation was 47.5% and the temperature was 25°C. 24 kg of the preparation are kept. 6 kg of wheat flour and 6 kg of tap water at 25°C are added. The homogenization of the mixture is carried out with a rotor-stator at 1500 rpm for 10 min. The preparation is kept at 25°C for 24 hours. The dry matter content of the fermented preparation was 42.5% and the temperature was 24.9°C. 30 kg of the preparation are kept. 2.94 kg of wheat flour and 12.06 kg of tap water at 25°C are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 10 min. The preparation is then kept at 25°C for 48 hours. The dry matter content of the fermented preparation was 34.4% and the temperature was 26.8°C. 40 kg of the preparation are kept. 16.3 kg of wheat flour and 23.7 kg of tap water previously cooled to 6°C are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 15 minutes. The preparation is then fermented at 15°C for 96h, with central agitation at 250rpm and counter-rotating (scraper) at 30rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min (Nl / min: air expanded at Normal Reference Atmosphere). The dry matter content of the fermented preparation was 33.51%. 40 kg of the preparation are kept. 16.6 kg of wheat flour and 23.4 kg of tap water previously cooled to 6°C are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 15 minutes. The preparation is then fermented at 15°C for 24 hours, with central agitation at 250rpm and counter-rotating (scraper) at 30rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. The MS of the fermented preparation was 34.85%, the temperature was 16.2°C. 40 kg of the preparation are kept. 16.1 kg of wheat flour and 23.9 kg of tap water previously cooled to 6°C are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 15 minutes. The preparation is then fermented at 15°C for 24 hours, with central agitation at 250rpm and counter-rotating (scraper) at 30 rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100Nl / min. The MS of the fermented preparation was 34.09%, the temperature was 17.3°C. 40 kg of the preparation are kept. 16.1 kg of wheat flour and 23.9 kg of tap water previously cooled to 6°C are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 15 minutes. The preparation is then fermented at 15°C for 96 hours, with central agitation at 250rpm and counter-rotating (scraper) at 30rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100Nl / min. The MS of the fermented preparation was 35.8%, the temperature was 17.3°C. The preparation is cooled to 4°C and stored at 4°C. This sourdough starter will be used later for bread, brioche, and panettone applications, the results of which are presented. Comparative example 1: 1 kg of wheat grains was weighed in a food-grade PP bucket. 5 litres of tap water at 15°C were added, then left to rest for 30 min at room temperature. Washing the wheat grains: The grains, immersed in water, were then rubbed by hand for 10 minutes, and then the water was drained. 5 liters of tap water at 15°C were added again, and the grains were rubbed again by hand (this operation was repeated five times successively). Rinsing the wheat grains: 5 liters of tap water at 25°C are poured over the wheat grains, then the grains are drained by manual pressing through a conical stainless steel sieve. The water is then discarded, while the grains are kept (this operation is repeated fifteen times successively). Final draining of the grains by manual pressing through a conical stainless steel sieve. Only the grains are retained. The kilo of washed and drained wheat grains are placed in a food-grade PP bucket. 4 kg of tap water at 25°C are added. The bucket is placed in an oven at 25°C for 67 hours. The preparation is drained by manual pressing through a conical stainless steel sieve in order to separate the liquid phase (juice) from the grains. Only the liquid phase is retained. 1750g of juice are weighed into a food-grade PP bucket. 1750g of wheat flour are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The dry matter content of the fermented preparation was 47.5% and the temperature was 25°C. 3300 g of preparation are weighed into a food-grade PP bucket. 825 g of wheat flour and 825 g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The dry matter content of the fermented preparation was 42.5% and the temperature was 24.9°C. 4800 g of preparation are weighed into a food-grade PP bucket. 470 g of wheat flour and 1930 g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 48 hours. The dry matter content of the fermented preparation was 34.4% and the temperature was 26.8°C. 500g of preparation are weighed into a food-grade PP bucket. 650g of wheat (no water added). The mixture is homogenized using a Kitchenaid 5KSM45 mixer with a flat beater, at speed 1 for 2 minutes. The preparation is then placed in an oven at 15°C for 96 hours. The dry matter content of the fermented preparation was 65.44% 500g of preparation are weighed into a food-grade PP bucket. 425 g of wheat flour and 75 g of tap water previously cooled to 6°C are added. The mixture is homogenized using a Kitchenaid 5KSM45 mixer with a flat beater, at speed 1 for 2 minutes. The preparation is then placed in an oven at 15°C for 24 hours. The dry matter content of the fermented preparation was 70.26% and the temperature was 15.2°C. 500g of preparation are weighed into a food-grade PP bucket. 400 g of wheat flour and 100 g of tap water previously cooled to 6°C are added. The dry matter content of the fermented preparation was 47.5% and the temperature was 25°C. The mixture is homogenized using a Kitchenaid 5KSM45 mixer with a flat beater, at speed 1 for 2 minutes. The preparation is then placed in an oven at 15°C for 24 hours. The MS of the fermented preparation was 71.14%, the temperature was 15.4°C. 500g of preparation are weighed into a food-grade PP bucket. 400 g of wheat flour and 100 g of tap water previously cooled to 6°C are added. The mixture is homogenized using a Kitenchaid 5KSM45 robot with a flat beater, at speed 1 for 2 minutes. The preparation is then placed in an incubator at 15°C for 96 hours. The MS of the fermented preparation was 70.9%, the temperature was 14.6°C. The preparation is placed in a climate chamber at 4°C to be cooled and stored at 4°C. This sourdough starter will be used later for bread, brioche, and panettone applications. Comparative example 2: 1 kg of wheat grains were weighed in a food-grade PP bucket. 5 litres of tap water at 15°C were added, then left to rest for 30 min at room temperature. Washing the wheat grains: The grains, immersed in water, were then rubbed by hand for 10 minutes, and then the water was drained. 5 liters of tap water at 15°C were added again, and the grains were rubbed again by hand (this operation was repeated five times successively). Rinsing the wheat grains: 5 liters of tap water at 25°C are poured over the wheat grains, then the grains are drained by manual pressing through a conical stainless steel sieve. The water is then discarded, while the grains are kept (this operation is repeated fifteen times successively). Final draining of the grains by manual pressing through a conical stainless steel sieve. Only the grains are retained. The kilo of washed and drained wheat grains are placed in a food-grade PP bucket. 4 kg of tap water at 25°C are added. The bucket is placed in an oven at 25°C for 67 hours. The preparation is drained by manual pressing through a conical stainless steel sieve in order to separate the liquid phase (juice) from the grains. Only the liquid phase is retained. 1750g of juice are weighed into a food-grade PP bucket. 1750g of wheat flour are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The dry matter content of the fermented preparation was 43.2% and the temperature was 25°C. 3300 g of preparation are weighed into a food-grade PP bucket. 829 g of wheat flour and 825 g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The dry matter content of the fermented preparation was 43.9% and the temperature was 25°C. 4800 g of preparation are weighed into a food-grade PP bucket. 1200g of wheat flour and 1200g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 48 hours. The dry matter content of the fermented preparation was 42.7% and the temperature was 26.2°C. 1000 g of preparation are weighed into a food-grade PP bucket. 311.66 g of wheat flour and 593.33 g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 96 hours. The dry matter content of the fermented preparation was 33.3% 1000 g of preparation are weighed into a food-grade PP bucket. 420g of wheat flour and 580g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The dry matter content of the fermented preparation was 34.99% and the temperature was 25°C. 1000 g of preparation are weighed into a food-grade PP bucket. 400g of wheat flour and 600g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The MS of the fermented preparation was 34.53%, the temperature was 24.8°C. 1000 g of preparation are weighed into a food-grade PP bucket. 400g of wheat flour and 600g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 96 hours. The dry matter content of the fermented preparation was 34.30%, and the temperature was 25.1°C. The preparation is placed in a climate chamber at 4°C to be cooled and stored at 4°C. This sourdough starter will be used later for bread, brioche, and panettone applications. Comparative example 3: 1.5 kg of wheat grains were weighed in a food-grade PP bucket. 5 litres of tap water at 15°C were added, then left to rest for 30 min at room temperature. Washing the wheat grains: The grains, immersed in water, were then rubbed by hand for 10 minutes, and then the water was drained. 5 liters of tap water at 15°C were added again, and the grains were rubbed again by hand (this operation was repeated five times successively). Rinsing the wheat grains: 5 liters of tap water at 25°C are poured over the wheat grains, then the grains are drained by manual pressing through a conical stainless steel sieve. The water is then discarded, while the grains are kept (this operation is repeated fifteen times successively). Final draining of the grains by manual pressing through a conical stainless steel sieve. Only the grains are retained. The 1.5 kg of washed and drained wheat grains are placed in a food-grade PP bucket. 6 kg of tap water at 25°C are added. The bucket is placed in an oven at 25°C for 67 hours. The preparation is drained by manual pressing through a conical stainless steel sieve in order to separate the liquid phase (juice) from the grains. Only the liquid phase is retained. 5000g of juice are weighed into a food-grade PP bucket. 5000g of wheat flour are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. The dry matter content of the fermented preparation was 44.8% and the temperature was 26.1°C. 4,500 g of preparation are weighed into a food-grade PP bucket. 1125 g of wheat flour and 1125 g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 24 hours. 4000 g of preparation are weighed into a food-grade PP bucket. 1000 g of wheat flour and 1000 g of tap water at 25°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 25°C for 48 hours. The dry matter content of the fermented preparation was 44.6% and the temperature was 25.6°C. 2000 g of preparation are weighed into a food-grade PP bucket. 600 g of wheat flour and 1400 g of tap water previously cooled to 6°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 8°C for 96 hours. The dry matter content of the fermented preparation was 35.18% and the temperature was 8.2°C. 2000 g of preparation are weighed into a food-grade PP bucket. 800 g of wheat flour and 1200 g of tap water previously cooled to 6°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 8°C for 24 hours. The dry matter content of the fermented preparation was 35.1% and the temperature was 7.8°C. 2000 g of preparation are weighed into a food-grade PP bucket. 800 g of wheat flour and 1200 g of tap water previously cooled to 6°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an oven at 8°C for 24 hours. The MS of the fermented preparation was 35.06%, the temperature was 8.2°C. 2000 g of preparation are weighed into a food-grade PP bucket. 800 g of wheat flour and 1200 g of tap water previously cooled to 6°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an incubator at 8°C for 24 hours. The MS of the fermented preparation was 35.42%, the temperature was 8°C. 2000 g of preparation are weighed into a food-grade PP bucket. 800 g of wheat flour and 1200 g of tap water previously cooled to 6°C are added. The mixture is homogenized manually with a kitchen whisk for 5 minutes. The preparation is then placed in an incubator at 8°C for 24 hours. The MS of the fermented preparation was 36.64%, the temperature was 8.2°C. The preparation is placed in a climate chamber at 4°C to be cooled and stored at 4°C. This sourdough starter will be used later for bread, brioche, and panettone applications. To obtain the results in Table I, bread, brioche and panettone were produced using the following processes respectively, using the spiral mixer VMISPI11. Speed ​​1: 70 rpm for the arm; 10 rpm for the tank. Speed ​​2: 160 rpm for the arm; 18 rpm for the tank. Method for making ordinary bread using sourdough without the addition of baker's yeast, as shown in example 1 and comparative examples 1, 2, 3, 4 and 5 Table I Order of steps to follow Type of flour French tradition flour 1 Weight of water The quantity of water added is adjusted according to the consistency of the sourdough (more or less liquid) in order to obtain doughs of equivalent consistency for optimal fermentation.Example 1: 1275 g are introduced into the mixer. Comparative example 1: 1425 g. Comparative example 2: 1275 g. Comparative example 3: 1275 g. Comparative example 4: 1200 g. Comparative example 5: 1200 g. 2. Weight of flour: 2000 g are introduced into the mixer. 3. Weight of sourdough starter: 200 g are introduced into the mixer. 4. Kneading: Spiral mixer, 5 min at speed 1, then 3 min at speed 2. 5. Weight of salt: 40 g are introduced into the mixer. 6. Kneading: 3 min at speed 2. 7. Dough temperature after kneading: 25-27°C. 8. First rise: 1 hour in a fermentation chamber at 25°C and 75% humidity. 9. Dividing: Manually divided into 350 g dough pieces. g and pre-forming into oval balls 10 Resting 20 min in fermentation chamber at 25°C and humidity of 75% 11 Shaping Batter or baguette format with weld underneath 12 Proofing 4 to 5 h in fermentation chamber at 25°C and humidity of 75% 13 Baking 20 min at 240°C with steam injection at the start of baking. Method for making brioche, without adding baker's yeast, using the sourdough starter from example 1 and comparative examples 1, 2, 3, 4 Table II Order of steps to follow Mixture of flours French tradition flour + Phil froid improver + semolina flour 1 Weight of egg The quantity of egg added is adjusted according to the consistency of the sourdough (more or less liquid) in order to obtain doughs of equivalent consistency for optimal fermentation. Example 1: 900 g are added to the mixer. Comparative example 1: 1050 g. Comparative example 2: 900 g. Comparative example 3: 900 g. Comparative example 4: 700 g. 2. Weight of sugar: 300 g are added to the mixer. 3. Weight of salt: 30 g are added to the mixer. 4. Weight of flours: 990 g of traditional flour + 10 g of Phil froid + 500 g of semolina flour are added to the mixer. 5. Weight of sourdough starter: 300 g are added to the mixer. 6. Kneading: Spiral mixer, 5 min at speed 1, then 15 min at speed 2. 7. Weight of butter: 600 g are added to the mixer. 8. Kneading: Spiral mixer, 5 min at speed 1.then 7 min at speed 9 Dough temperature after kneading 25-28°C 10 First rise 1 hr 30 min in fermentation chamber at 25°C and 75% humidity 11 Division Manual division into 300g dough pieces and pre-shaping into oval balls 12 Rest 15 min in fermentation chamber at 25°C and 75% humidity 13 Shaping In cardboard molds 14 Proofing 16 hr in fermentation chamber at 22°C and 75% humidity 15 Baking 18 min at 160°C with steam injection upon entry, fan oven, Method for making panettone, without the addition of baker's yeast, using the sourdough starter from example 1 and comparative examples 1, 2 and 4 Table III Order of steps to follow Type of flour Panettone mix 1 Weight of water The quantity of water added is adjusted according to the consistency of the starter (more or less liquid) in order to obtain doughs of equivalent consistency for optimal fermentation.Example 1: 450g are added to the mixer. Comparative example 1: 550g. Comparative example 2: 450g. Comparative example 4: 375g. 2. Weight of flour: 1000g of panettone mix. 3. Weight of sourdough starter: 200g are added to the mixer. 4. Kneading: Spiral mixer, 5 min at speed 1, then 10 min at speed 2. 5. Weight of butter: 300g are added to the mixer. 6. Kneading: Spiral mixer, 5 min at speed 1. 7. Weight of fruit: 460g are added to the mixer. 8. Kneading: Spiral mixer, 1 min at speed 1. 9. Dough temperature after kneading: 24-26°C. 10. Proofing: 1 hour 30 minutes in a fermentation chamber at 25°C and humidity of 75% 11 Division Manual division into 700g dough pieces and pre-forming into oval balls 12 Rest 20 min in fermentation chamber at 25°C and humidity of 75% 13 Shaping Manual into balls 14 Proof 16 h in fermentation chamber at 24°C and humidity of 75% 15 Baking 45 min at 150°C with steam injection upon loading into the oven, fan oven. Method for making sourdough bread using the sourdough starter from comparative example 6 Table IV Order of steps to follow Type of flour French tradition flour + rye flour T170 1 Weight of water The quantity of water added is adjusted according to the consistency of the sourdough (more or less liquid) in order to obtain doughs of equivalent consistency for optimal fermentation.1180g of water are added to the mixer if using sourdough starter of the invention; 1100g for commercial sourdough starter. 2. Weight of salt: 36g are added to the mixer. 3. Weight of flour: 1800g of traditional French flour + 200g of T170 rye flour are added to the mixer. 4. Weight of sourdough starter: For sourdough starter according to the invention: 20g are added to the mixer. For commercial sourdough starter: 100g are added to the mixer. 5. Kneading: Spiral mixer, 5 minutes at speed 1, then 30 seconds at speed 2. 6. Dough temperature after kneading: 25-27°C. 7. Proofing: 14 hours in a fermentation chamber at 23°C and 75% humidity. 8. Division: Manual division into 1000g dough pieces. 350g, pre-forming into oval balls 9 Resting 20 min in fermentation chamber at 25°C and humidity of 75% 10 Shaping into balls 11 Proofing 3 h in fermentation chamber at 25°C and humidity of 75% 12 Baking 50 min at 230°C / 240°C with steam injection at the start of baking. Comparative examples 4 and 5: Bread was prepared according to the recipe in Table I using two commercial sourdough starters claiming to produce bread without the addition of yeast. The results obtained were shown in Table V. Comparative example 6: Sourdough bread was prepared using 1% by weight of flour of a sourdough starter according to the invention and 5% by weight of flour of a commercial sourdough starter claiming to produce sourdough bread without the addition of yeast. The results obtained comply with French legislation (Decree No. 93-1074 of September 13, 1993). TABLE V Measurement performed solely on bread dough. Results: Mass volumes of breads DM pH ATT Acetic acid Lactic acid Yeast log (CFU) / g Lactic acid bacteria log (CFU) / g Volume 2h rise Volume 3h rise Volume 4h rise Volume 5h rise Volume 6h rise Bread Brioche Panettone Example 1 35.8 5.89 2 87 0 8.81 9.60 1.5 1.8 2.4 3 3.5 Success 3.93 5.09 3.87 Comparative example 1 70.9 4.03 9.5 1032 5640 6.89 8.59 1 1 1.1 1.3 1.5 Failure 2.67 3.55 3.09 Comparative example 2 34.3 3.56 14 734 7 662 5.90 9.08 1.1 1.2 1.4 1.5 1.6 Failure 1.89 1.06 1.76 Comparative Example 3 36.64 4.34 5.2 305 2 942 4.85 8.56 1 1 1 1 1 Failure 1.86 1.45 - Comparative Example 4 16.65 4.21 22.4 6 452 17 809 7.11 8.20 1.2 1.2 1.2 1.2 - Failure 2.14 1.96 2.18 Comparative Example 5 29.21 3.75 14.1 2327 2925 5.76 7.52 1 1 1 1 - Fail 1.94 - - Parameter units: MS: % ������������������� ����� Acetic acid: ppm Lactic acid: ppm ������������������� ����� Yeasts: log (cfu) / g Lactic acid bacteria: log (cFU) / g Specific volume: cm³ / g Comparative example 7 (air supply too early): The procedure is as follows: TABLE VI (1 / 2) Day 0, Step 1: 10 kg of organic wheat grains were weighed into a food-grade PP bucket. 30 liters of tap water at 15°C were added, and the mixture was left to stand for 30 minutes at room temperature. Washing the wheat grains: the grains, immersed in water, were then rubbed by hand for 10 minutes, and the water was drained. 30 liters of tap water at 15°C were added again, and the grains were rubbed by hand once more. This process was repeated five times. Rinsing the wheat grains: 30 liters of tap water at 25°C were poured over the wheat grains, and then the grains were drained by hand-pressing through a stainless steel conical sieve. The water is then discarded, while the grains are retained. This process is repeated 15 times. Step 2: Final draining of the grains by manual pressing through a conical stainless steel sieve. Only the grains are retained.Step 3: The 10 kg of washed and drained organic wheat grains are introduced into a Goavec stainless steel fermenter (trademark). 40 kg of tap water at 25°C are added. Step 4: The preparation is maintained at 25°C for 72 hours. The preparation is subjected to central stirring at 150 rpm and counter-rotating stirring (scraper) at 30 rpm, and to continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min. (Nl / min: air at normal reference atmosphere). Step 5: The temperature of the preparation is 26.4°C. The preparation is removed from the stainless steel fermenter (juice + grains). Only the liquid phase (juice) is retained. Step 6: 30 kg of juice are weighed and placed in a Goavec stainless steel fermenter (brand name). 30 kg of T80 wheat flour are added. The mixture is homogenized using a rotor-stator agitator at 1500 rpm for 10 minutes.The preparation is maintained at 25°C for 24 hours. It is stirred centrally at 150 rpm and counter-rotatingly (scraper) at 50 rpm, and continuously aerated by injecting degreased, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min. Day 4, Step 7: The dry matter content of the fermented preparation is 45.25% and the temperature is 25.64°C. 39.6 kg of the preparation are retained. 9.9 kg of T80 wheat flour and 9.9 kg of tap water at 25°C are added. The mixture is homogenized with a rotor-stator mixer at 1500 rpm for 10 minutes. The preparation is then maintained at 25°C for 24 h. The preparation is placed under central agitation at 150 rpm and counter-rotating (scraper) at 50 rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min.TABLE VI (2 / 2) J5 Step 8 The dry matter content of the fermented preparation is 45.02% and the temperature is 26°C. 40 kg of the preparation are retained. 3.918 kg of T80 wheat flour and 16.1 kg of tap water at 25°C are added. The mixture is homogenized using a rotor-stator mixer at 1500 rpm for 10 minutes. The preparation is then maintained at 25°C for 48 hours. The preparation is stirred centrally at 200 rpm and counter-rotatingly (scraper) at 50 rpm, and continuously aerated by injecting degreased, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min. Day 7, Step 9: The dry matter content of the fermented preparation is 34.26% and the temperature is 24.81°C. 24 kg of the preparation are retained. 9.776 kg of T80 wheat flour and 14.2 kg of tap water at 25°C are added. The mixture is homogenized with a rotor-stator mixer at 1500 rpm for 15 minutes.The preparation is then fermented at 25°C for 72 hours. It is stirred centrally at 200 rpm and counter-rotatingly (scraper) at 50 rpm, and continuously aerated by injecting dry, degreased compressed air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min (Nl / min: air at Standard Reference Atmosphere). Day 10, Step 10: The dry matter content of the fermented preparation is 33.16% and the temperature is 26.64°C. 25 kg of the preparation are retained. 10.4 kg of T80 wheat flour and 14.6 kg of tap water at 15°C are added. The mixture is homogenized using a rotor-stator agitator at 1500 rpm for 15 min. The preparation is then fermented at 15°C for 96 h.The preparation is stirred centrally at 250 rpm and counter-rotatingly (scraper) at 15 rpm, and continuously aerated by injecting deoil-free, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min. Day 14, Step 11: The dry matter content of the fermented preparation is 37.85% and the temperature is 15.37°C. 25 kg of the preparation are retained. 10 kg of T80 wheat flour and 15 kg of tap water at 15°C are added. The mixture is homogenized with a rotor-stator mixer at 1500 rpm for 15 minutes. The preparation is then fermented at 15°C for 24 hours. The preparation is stirred centrally at 250 rpm and counter-rotatingly (scraper) at 15 rpm, and continuously aerated by injecting deoil-free, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 60 Nl / min. Day 15: Fermentation stopped. The temperature of the preparation is 16°C.The preparation is cooled to 4°C and stored at 4°C. This sourdough starter is tested for applications on bread, brioche, panettone and sourdough bread. Comparative example 8 (perfected sourdough starter): The procedure is as follows: TABLE VII (1 / 3) Day 0, Step 1: 6 kg of organic wheat grains were weighed into a food-grade PP bucket. 30 liters of tap water at 15°C were added, and the mixture was left to stand for 30 minutes at room temperature. Washing the wheat grains: the grains, immersed in water, were then rubbed by hand for 10 minutes, and the water was drained. 30 liters of tap water at 15°C were added again, and the grains were rubbed by hand once more. This process was repeated 5 times. Rinsing the wheat grains: 30 liters of tap water at 25°C were poured over the wheat grains, and then the grains were drained by hand-pressing through a stainless steel conical sieve. The water is then discarded, while the grains are retained. This process is repeated 15 times. Step 2: Final draining of the grains by manual pressing through a conical stainless steel sieve. Only the grains are retained.Step 3: The 6 kg of washed and drained organic wheat grains are placed in a food-grade PP bucket. 24 kg of tap water at 25°C are added. Step 4: The bucket is placed in a 25°C oven for 67 hours. Step 5: The preparation is drained by manual pressing through a conical stainless steel sieve to separate the liquid phase (juice) from the grains. Only the liquid phase is retained. Step 6: 20 kg of juice are weighed and placed in a Goavec stainless steel fermenter (brand name). 20 kg of T80 wheat flour are added. The mixture is homogenized using a rotor-stator mixer at 1500 rpm for 10 minutes. The preparation is maintained at 25°C for 24 hours under gentle central stirring at 80 rpm and counter-rotating stirring (scraper) at 15 rpm. Day 4, Step 7: The dry matter content of the fermented preparation is 43.7% and the temperature is 24.9°C. 40 kg of the preparation are retained. 10 kg of T80 wheat flour and 10 kg of tap water at 25°C are added.The mixture is homogenized using a rotor-stator mixer at 1500 rpm for 10 minutes. The preparation is then maintained at 25°C for 24 hours under gentle central stirring at 80 rpm and counter-rotating stirring (scraper) at 15 rpm. Day 5, Step 8: The dry matter content of the fermented preparation is 43.2% and the temperature is 25.8°C. 40 kg of the preparation are retained. 10 kg of T80 wheat flour and 10 kg of tap water at 25°C are added. The mixture is homogenized again using a rotor-stator mixer at 1500 rpm for 10 minutes. The preparation is then maintained at 25°C for 48 h under low central agitation at 80 rpm and counter-rotating (scraper) at 15 rpm. TABLE VII (2 / 3) Day 7, Step 9: The dry matter content of the fermented preparation is 42.3% and the temperature is 25.5°C. 30 kg of the preparation are retained. 15 kg of T80 wheat flour and 15 kg of tap water, previously cooled to 6°C, are added. The mixture is homogenized using a rotor-stator mixer at 1500 rpm for 15 minutes. The preparation is then fermented at 11°C for 7 days with central stirring at 250 rpm and counter-rotating stirring (scraper) at 30 rpm, under continuous aeration by injecting deoil-free, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min (Nl / min: air at Standard Reference Atmosphere). Day 14, Step 10: The dry matter content of the fermented preparation is 41.8% and the temperature is 11.5°C. 30 kg of the preparation are retained. 14.8 kg of T80 wheat flour and 15.2 kg of tap water, previously cooled to 6°C, are added.The mixture is homogenized using a rotor-stator agitator at 1500 rpm for 15 minutes. The preparation is then fermented at 11°C for 48 hours with central stirring at 250 rpm and counter-rotating stirring (scraper) at 30 rpm, under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. Day 16, Step 11: The dry matter content of the fermented preparation is 42.1% and the temperature is 12.5°C. 30 kg of the preparation are retained. 14.8 kg of T80 wheat flour and 15.2 kg of tap water previously cooled to 6°C are added. The mixture is homogenized with a rotor-stator mixer at 1500 rpm for 15 minutes.The preparation is then fermented at 11°C for 48 hours with central stirring at 250 rpm and counter-rotating stirring (scraper) at 30 rpm, under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. Day 18, Step 12: The dry matter content of the fermented preparation is 41.1% and the temperature is 11.6°C. 30 kg of the preparation are retained. 17.7 kg of T80 wheat flour and 12.3 kg of tap water, previously cooled to 6°C, are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 15 min. The preparation is then fermented at 11°C for 48 h with central agitation at 250 rpm and counter-rotating agitation (scraper) at 30 rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min.Day 20, Step 13 (Step 12 is repeated): The dry matter content of the fermented preparation is 45.6% and the temperature is 14.5°C. 30 kg of the preparation are retained. 17.3 kg of T80 wheat flour and 12.7 kg of tap water, previously cooled to 6°C, are added. The mixture is homogenized using a rotor-stator mixer at 1500 rpm for 15 minutes. The preparation is then fermented at 11°C for 48 h with central agitation at 250 rpm and counter-rotating (scraper) at 30 rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. TABLE VII (3 / 3) Day 22, Step 14 (Step 13 is repeated): The dry matter content of the fermented preparation is 45.9% and the temperature is 13.4°C. 30 kg of the preparation are retained. 17.3 kg of T80 wheat flour and 12.7 kg of tap water, previously cooled to 6°C, are added. The mixture is homogenized using a rotor-stator mixer at 1500 rpm for 15 minutes. The preparation is then fermented at 11°C for 48 hours with central stirring at 250 rpm and counter-rotating stirring (scraper) at 30 rpm, under continuous aeration by injecting defatted, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. Day 24, Step 15 (Step 13 is repeated): The dry matter content of the fermented preparation is 46.7% and the temperature is 13.6°C. 30 kg of the preparation are retained. 17.3 kg of T80 wheat flour and 12.7 kg of tap water, previously cooled to 6°C, are added.The mixture is homogenized using a rotor-stator agitator at 1500 rpm for 15 minutes. The preparation is then fermented at 11°C for 48 hours with central stirring at 250 rpm and counter-rotating stirring (scraper) at 30 rpm, under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. Day 26, Step 16 (Step 13 is repeated): The dry matter content of the fermented preparation is 46.6% and the temperature is 13.3°C. 30 kg of the preparation are retained. 17.3 kg of T80 wheat flour and 12.7 kg of tap water previously cooled to 6°C are added. The mixture is homogenized with a rotor-stator mixer at 1500 rpm for 15 minutes.The preparation is then fermented at 11°C for 48 hours with central stirring at 250 rpm and counter-rotating stirring (scraper) at 30 rpm, under continuous aeration by injecting defatted, compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min. Day 28, Step 17 (Step 13 is repeated): The dry matter content of the fermented preparation is 47.1% and the temperature is 13°C. 30 kg of the preparation are retained. 17.3 kg of T80 wheat flour and 12.7 kg of tap water, previously cooled to 6°C, are added. The mixture is homogenized with a rotor-stator agitator at 1500 rpm for 15 min. The preparation is then fermented at 11°C for 48 h with central agitation at 250 rpm and counter-rotating agitation (scraper) at 30 rpm and under continuous aeration by injecting deoil-free compressed dry air through a sparger at the bottom of the tank at a pressure of 6 bar and a flow rate of 100 Nl / min.Day 30: Fermentation stopped. The dry matter content of the fermented preparation is 47.1% and the temperature is 13.9°C. The preparation is cooled to 4°C and stored at 44°C. This sourdough starter is tested for applications in bread, brioche, panettone, and sourdough bread. TABLE VIII Order of steps to follow Type of flour French tradition flour + rye flour T170 Base temperature 65°C 1 Weight in water The quantity of water added is adjusted according to the consistency of the sourdough (more or less liquid) in order to obtain doughs of equivalent consistency for optimal fermentation.Example D2 isara j+15������� �����������:���� 1140 g Example Spicher v3����������� ����������:���� 1140 g Example according to the invention, improved:���� 1140 g 2 Weight of salt 36 g are introduced into the mixer 3 Weight of flour 1800 g of traditional French flour + 200 g of T170 rye flour are introduced into the mixer 4 Weight of sourdough starter 40 g are introduced into the mixer 5 Kneading Spiral mixer 5 min at 1st speed, then 30 seconds at 2nd speed 6 Temperature of the dough at the end of kneading 25 to 27°C 7 Proofing 14 h in a proofing chamber 8. Fermentation at 23°C and humidity of 75%. 9. Division: Manual division into 1000g and 350g dough pieces, pre-forming into oval balls. 10. Rest: 20 min in fermentation chamber at 25°C and humidity of 75%. 11. Shaping: Into balls. 12. Proofing: 3 h in fermentation chamber at 25°C and humidity of 75%. 13. Baking: 50 min at 230 / 240°C with steam injection upon entering the oven for 1kg dough pieces and 25 min for 350g dough pieces. The sourdough bread production test is carried out following the operating protocol indicated in Table VIII with the "Spicher" sourdough starters, that of comparative example 7 and that of comparative example 8. The results obtained are grouped in Table IX. TABLE IX Measurements taken only on bread dough. Mass volumes in cm³ / g. Application for sourdough bread. DM pH ATT Acetates Lactates Yeast log (CFU) / g Lactic acid bacteria Log (CFU) / g Rise at 2 h Rise at 3 h Rise at 4 h Rise at 5 h Rise at 6 h Bread Brioche Panettone Sourdough bread Bread pH Bread acetate (ppm) Comparative example 7 34.96 3.74 12.7 2 517 4 206 9.23 9.40 1.2 1.6 1.8 2 2.2 2.81 3.86 2.83 1.85 3.91 650 Spicher* 43.16 3.93 15.3 819 6 904 7.48 8.64 1.3 1.3 1.4 1.4 1.7 2.88 2.26 2.52 2.50 4.02 148 Comparative example 8 47.24 3.92 11.1 425 5 334 7.64 9.30 1.4 1.6 2 2.2 3 4.30 4.79 2.69 2.48 3.92 910 * Spicher est le levain prÿ�parÿ� selon Spicher G ET Al "Investigations on the characterization and evaluation of a spontaneous sourdough starter." Influence of the guiding conditions on the course of spontaneous fermentation. Geheide Mehl und Brot Bochum DE vol 4 No. 12 complète par Investigation on the characterization and evaluation of various methods for the preparation of a spontaneous sourdough starter 1st communication: Comparison of different methods No. 5487 of the Federal Research Institute for Cereal and Potato Processing. Detmold p 18-122. Le vain de l'exemple comparatif 7, dans lequel on a proc�d� avec insufflation d'air d�s le stade a), donne un taux d'ac�tate trop grand et des pousses � 5 h et � 6 h insuffisantes et a volume de pain insuffisant. The levain spicher donne des pousses � 5 h and � 6 h insufficient and a taux d'ac�tate in the pain au levain insufficient suivant la l�gislation. Measurement of pH, ac�tates and lactates of pain: During sourdough bread making, the endogenous production of organic acids is assessed in the raw dough. The analysis of the baked sourdough is performed only on the crumb. 25 g of crumb or dough are taken, and then 225 ml of reverse osmosis water are precisely added. The mixture is homogenized for 5 minutes using an ultra-Turrax (IKA (trademark) DI 25 basic) at 20,000 rpm. The pH measurement is carried out on this mixture, under stirring, with a Mettler Toldeo (trademark) G20 model pH meter. For the determination of acetic and lactic acid content, the mixture is first centrifuged at 12,000 g for 20 min. The supernatant is collected. Analysis is performed on this sample using an enzymatic method with ENZYTEC™ D- / L-Lactic acid and ENZYTEC™ acetic acid kits (Scil Diagnostic GmbH, Germany). Results are expressed in ppm (parts per million = mg / kg of bread or dough). Paintings Endogenous production of acetic acid during sourdough bread production. Perfected Sourdough Starter Spicher Sourdough For pH After kneading 6.27 6.25 During shaping 4.00 4.12 Before baking 3.89 4.03 Bread crumb 3.92 4.02 Mass volume of sourdough bread 2.48 2.50 For acetate After kneading 425 - During shaping 716 100 Before baking 867 122 Bread crumb 910 148 For lactate After kneading 808 785 During shaping 5025 4393 Before baking 5452 4760 Bread crumb 5655 4786 This table shows the monitoring for the production of endogenous acids during the making of sourdough bread. There is endogenous production of the two major acids in sourdough. In terms of acidity (pH and acetate levels of the bread), only perfected sourdough meets the legal criteria.

Claims

REVENDICATIONS 1. Procédé de production d'un levain, dans lequel successivement : a) on nettoie une matrice fermentescible à l'eau en l'immergeant complètement dans de l'eau et en faisant s'écouler de l'eau jusqu'à ce que l'eau qui s'écoule soit limpide, de manière à obtenir une matrice nettoyée, ou bien contenant encore de 200 g à 1,5 Kg d'eau résiduelle par 2 Kg de matrice que l'on incube ou bien en contenant moins et, dans ce dernier cas, on immerge la matrice nettoyée dans de l'eau entre 15°C et 35°C à raison de 1 Kg à 20 Kg d'eau par 2 Kg de matrice que l'on incube, l'incubation se faisant entre 10 et 35°C jusqu'à apparition de bulles à la surface du liquide (dit jus), de manière à obtenir une matrice incubée, b) on sépare le jus du reste de la matrice incubée, c) on mélange le jus à du substrat pour obtenir un mélange ayant une teneur en matière sèche en poids comprise entre 15 et 60% et on laisse fermenter pendant 12 à 72 h entre 9°C et 25°C pour obtenir un milieu et d) on ajoute, au milieu du substrat et de l'eau entre 10°C et 35°C, l'apport de substrat et d'eau représentant de 25 à 75% du volume total et on laisse fermenter pendant 12 à 72 h entre 9°C et 25°C avec insufflation d'air, d'oxygène ou d’un mélange contenant de l’oxygène, à un débit compris entre 0,01 m3 / h / kg de produit à 10 m3 / h / kg de produit, pour obtenir du levain.

2. Procédé suivant la revendication 1, caractérisé en ce que l'on répète plusieurs fois, de préférence trois fois, les stades c) et d).

3. Procédé suivant la revendication 1 ou 2, caractérisé en ce que la matrice fermentescible comprend : - des céréales telles que blé tendre, blé dur, seigle, des pseudo-céréales telles que sarrasin, quinoa, des légumineuses sous toutes leurs formes telles que graines entières sèches ou germées, farines, semoules et autres fractions telles que sons, germes, - tous les fruits tels que pomme, poire, banane, et les fruits secs, entiers ou parties telles que peau, chair, pulpe, pépins, frais et transformés tels que séchés, jus, mouts fermentés, - bois de la vigne tels que sarment, copeaux, - choux, houblons, malts tels que blé, orge, miel.

4. Procédé suivant l'une des revendications précédentes, caractérisé en ce que le substrat comprend de la farine ou toute autre fraction de céréale ou pseudo-céréale ou légumineuse.

5. Procédé suivant l'une des revendications précédentes, caractérisé en ce que l'on répète au moins trois fois le stade d).

6. Procédé suivant l'une des revendications précédentes, caractérisé en ce que l'on fait suivre le stade d) d'un stade e), dans lequel on répète le stade d), mais avec une teneur en matière sèche allant de 30 à 60%.

7. Procédé suivant la revendication 6, caractérisé en ce que l'on répète le stade e) au moins trois fois.

8. Procédé suivant la revendication 6 ou 7, caractérisé en ce que le substrat a une teneur en cendres supérieure à 0,75% en poids.

9. Levain ayant un pH compris entre 3 et 6, un taux d'acide acétique inférieur à 2 000 ppm, un taux d’acide lactique inférieur à 8 000 ppm, un taux de levures en log(ufc) / g compris entre 7 et 9, un taux de bactéries lactiques en log(ufc) / g supérieur compris entre 8 et 10 et qui, utilisé dans un test de boulangerie dans un procédé de préparation de pain selon les stades successifs suivants : on introduit dans l'ordre, dans un pétrin à spirale à bras et cuve entraînés en rotation, 1 275 g d'eau, 2 000 g de farine et 200 g de levain, on les pétrit pendant 5 min à une vitesse de 70 t / min du bras et de 10 t / min de la cuve, on introduit 40 g de sel dans le pétrin, on pétrit pendant 3 min à une vitesse de 160 t / min du bras et 18 t / min de la cuve, de manière à obtenir une température de la pâte en sortie de pétrissage de 25 à 27°C, on effectue un pointage de la pâte pendant 1 h en chambre de fermentation à 25°C et à une hygrométrie de 75%, on effectue une division manuelle de la pâte en pâtons de 350 g que l'on préforme en boules ovales, on détend pendant 20 min en chambre de fermentation à 25°C et à une hygrométrie de 75%, on effectue un façonnage en format bâtard ou baguette avec soudure dessus, on effectue un apprêt de 4 à 5 h en chambre de fermentation à 25°C et à une hygrométrie de 75% et enfin une cuisson pendant 20 min à 240°C avec injection de buée à l'enfournement, donne une pâte avant cuisson ayant une mesure de pousse à 5 h en cm supérieure à 2, une mesure de pousse à 6 h supérieure à 2,8, et cette pâte cuite donne un pain qui a un volume massique au moins égal à 3 cm3 / g.

10. Levain suivant la revendication 9, caractérisé en ce que, de préférence, le taux d'acétate du pain est supérieur à 900 ppm et son pH inférieur à 4,3.