Process for improving the efficiency of a spirits distillate ageing

Abstract

The present invention relates to a process for improving the efficiency of a spirits distillate ageing comprising the following steps: a) preparing: at least one reactor, wood chips or cubes, at least one ultrasound source, a distillate to be submitted to ageing; b) introducing the wood chips or cubes and the distillate into the at least one reactor; c) inserting the at least one reactor prepared in the previous step into the at least one ultrasound source; d) operating the ultrasound source and allowing the distillate to age, wherein: in step a) of preparing the at least one reactor, wood chips or cubes, at least one ultrasound source, a distillate to be submitted to ageing, wood chips or cubes whose surface area is between 70 and 500 cm2 per litre of distillate are used; step d) of operating the at least one ultrasound source and allowing the distillate to age is carried out in the absence of light, at a temperature between 0 °C and 40 °C, with a number of operating-rest cycles of the at least one ultrasound source between 200 and 4500.

Description

[0001] TITLE: “Process for improving the efficiency of a spirits distillate ageing”

[0002] DESCRIPTION

[0003] FIELD OF THE INVENTION

[0004] The invention falls within the technical field of ageing processes for spirits distillates carried out in laboratories or industrial plants, which do not use traditional wooden casks, achieving the same or better organoleptic properties and process efficiency, in terms of speed and / or yield, than traditional or other ageing processes.

[0005] STATE OF THE ART

[0006] Most of the spirits on the market are characterised by a maturation process in which the distillate remains inside wooden casks for a time varying from 3 to over 70 years. During maturation, several chemical-physical reactions take place characterising the end product, giving it the characteristic aromatic profile that makes it particularly appreciated on the market and determining the high economic value thereof, which is almost always proportional to the residence time inside the cask.

[0007] An example of a spirit distillate is whisky. Whisky is a distilled alcoholic beverage obtained from the fermentation of cereals such as barley, rye, maize or wheat, and aged in wooden casks for a period of time that varies depending on the style of whisky produced. The definition of whisky may vary according to the legislation of the different producing countries and regulatory bodies, but in general it is an alcoholic beverage with an ethyl alcohol content higher than 40% by volume.

[0008] The whisky industry is constantly evolving, seeking new methods and technologies to accelerate the maturation process of spirits. In this context, one of the recent approaches is the use of ultrasounds, which promises to reduce the time required for whisky maturation without compromising the quality of the end product.

[0009] Problem of the prior art

[0010] Although ageing / maturation processes for spirits distillates using ultrasound baths are known in the state of the art, there is a need to further simplify and make these processes more efficient by better controlling the reaction parameters in order to increase the yield thereof and make the finished product as similar as possible to one obtained through traditional cask ageing techniques.

[0011] For example, they are known ageing processes that employ ultrasound baths in which the distillate undergoes several sequential steps (e.g. initially, ultrasound cavitation is applied in the presence of wood chips; then, heating is applied in the presence of wood chips; next, ultrasound cavitation is applied in the absence of wood chips; then, aeration and oxidation is applied in the absence of wood chips; finally, heating is applied in the absence of wood chips). In this context, “block” systems or plants are required, wherein each block operates one operating step (sonication or heating or oxygenation), complicating and burdening the process, with greater expenditure of resources and energy and the difficulty of making individual process parameters more efficient. It is clear that, in this case, the sonication step cannot be separated from the subsequent steps in order to obtain an aged end product.

[0012] For other known processes, although the use of sonication is contemplated, the latter is not sufficient to obtain an aged end product, since a step of ageing the distillate in the cask must also be applied.

[0013] Last but not least, process conditions are required to be flexible and to be carried out in batch or semi-continuous or continuous mode.

[0014] SUMMARY OF THE INVENTION

[0015] The Applicant developed a process for improving the efficiency of a spirits distillate ageing comprising the following steps: a) preparing: at least one reactor, wood chips or cubes, at least one ultrasound source, a distillate to be submitted to ageing, b) introducing the wood chips or cubes and the distillate into the at least one reactor, c) inserting (or connecting) the at least one reactor prepared in the previous step into (or to) the at least one ultrasound source, and d) operating the at least one ultrasound source and allowing the distillate to age, wherein in step a) of preparing at least one reactor, wood chips or cubes, at least one ultrasound source, a distillate to be submitted to ageing, wood chips or cubes whose surface area is between 70 and 500 cm2per litre of distillate are used, step d) of operating the at least one ultrasound source and allowing the distillate to age is carried out:

[0016] - in the absence of light,

[0017] - at a temperature between 0 °C and 40 °C,

[0018] - with a number of operating-rest cycles of at least one ultrasound source between 200 and 4500.

[0019] This process is developed in a plant for improving the efficiency of a spirits distillate ageing process comprising:

[0020] - at least one reactor, preferably at least two reactors arranged in series,

[0021] - at least one ultrasound source,

[0022] - temperature control systems,

[0023] - pumping systems to send the distillate to the at least one reactor,

[0024] - pumping systems to introduce oxygen into the at least one reactor.

[0025] Advantages o f the invention

[0026] The invention consists in a process that enables the maturation of spirits to be more efficient and / or faster by using ultrasounds to extract the compounds from wood, by monitoring and effectively controlling the process parameters.

[0027] The distilled product is put in contact with wood chips or cubes and simultaneously submitted to several sonication cycles and to certain temperature conditions.

[0028] The process thus created is capable of producing, in a shorter period of time, an end product with chemical / physical specifications comparable to a product aged in casks for 4 / 6 years.

[0029] The advantages related to the process of the invention are: - reduction of the warehouse costs and reduction of the cost of staff involved in the different steps of the maturation process;

[0030] - the process does not involve a “block” plant, in which each block is provided to carry out a certain single operating step, such as sonication, or heating, or oxygenation;

[0031] - reduction of product losses during the maturation / aging step, resulting in higher production yields;

[0032] - possibility of controlling the extraction of compounds and consequently acting on the organoleptic profile of the product;

[0033] - reduction in production times compared to known processes;

[0034] - transversality. For example, the process is adaptable to all the distillates involving a maturation period in the cask; moreover, it is applicable in batch conditions or in semi- continuous or continuous working conditions.

[0035] DESCRIPTION OF THE DRAWINGS

[0036] Figures 1-16 - Results referring to compounds conferring colour and / or organoleptic characteristics as a function of sample reactions respectively: G-000, G-100, G-200, G-300, G-400, G-500, G-600, G-700, G-800, G-900, M-000, M-100, M-200, M-300, M-400, M-500 (axis y [ppm]; axis x: [minutes]), whose operating conditions, for each sample, are given in Tables 1A and IB in Example 1.

[0037] Figure 17 - Trend of the amber colouring as reactions proceed for samples G-000 to M-500, whose operating conditions are shown in Tables 1A and IB. Note that, from left to right, the amber colour tends to become stronger.

[0038] Figure 18 - Example of the reaction process of the invention carried out in batch.

[0039] Figure 19 - Example of the reaction process of the invention carried out in semi- continuous working conditions.

[0040] Figure 20 - Prototype of a continuous industrial plant wherein the process of the invention is carried out.

[0041] Figure 21 - Example of an initial configuration of a plant operating in continuous working conditions, but also capable of operating semi-continuously or discontinuously, with external recirculation. The distillate runs through the bed containing the wood several times. A start-up time is provided to get up to speed, so that the initial tank then behaves as a perfectly mixed system. The bed containing the wood can be divided into several segments interspersed with heat exchangers to maintain thermal control and avoid normal heating due to the presence of ultrasounds.

[0042] Figure 22 - Example of a second configuration of a plant operating continuously. The main difference from the first configuration in Figure 21 lies in the separation of the fresh distillate from the aged distillate into two separate tanks, positioned upstream and downstream of the ultrasound system respectively. According to this second configuration, the distillate runs once through the bed containing the wood. The bed containing the wood can be divided into several segments interspersed with heat exchangers to maintain thermal control and avoid normal heating due to the presence of ultrasounds.

[0043] DETAILED DESCRIPTION OF THE INVENTION

[0044] Process for improving the efficiency of a spirits distillate ageing

[0045] A process for improving the efficiency of a spirits distillate ageing refers to a process capable of making the ageing process of a spirits distillate more efficient in terms of process speed and / or yield and / or organoleptic characteristics of the product obtained.

[0046] Ageing of a spirits distillate refers to the maturation process of a spirits distillate capable of providing particular aesthetic (colour) and organoleptic properties. Traditional ageing involves the use of wooden casks, usually made of durmast or oak wood, and characterised by different shapes and sizes, depending on which a different type of ageing will take place.

[0047] A spirits distillate is defined as a beverage containing more than 21% ethyl alcohol by volume.

[0048] Preferably, the ABV% index of the distillate is between 45% and 67%, preferably between 45% and 65%, preferably between 45% and 63%, preferably of 43% or 63%.

[0049] The ABV index refers to the Alcohol By Volume percentage indicating the volume ratio, i.e. the amount of alcohol present in the solution expressed as the ratio of the volume of ethanol to the volume of total solution. The ABV index is different from the ABW o Alcohol By Weight index, which refers to the ratio by weight.

[0050] A reactor is defined as a container for producing and controlling chemical reactions; for example, a reaction flask, or a tube or, on a larger scale, an industrial plant.

[0051] Wood chips or cubes

[0052] Wood chips are characterised by a non-specific size and / or shape.

[0053] Wood cubes are characterised by a specific size and / or shape.

[0054] According to a particularly preferred embodiment, wood cubes characterised by a regular parallelepiped size are used for the process of the invention.

[0055] Preferably, the wood cubes have a size whereby: the width is preferably between 1 and 2 cm, preferably between 0.5 and 1 cm, preferably of 0.5 cm; the depth is preferably between 1 and 2 cm, preferably between 0.5 and 1 cm, preferably of 0.5 cm; the height is preferably between 2 and 2.5 cm, preferably between 1 and 2 cm, preferably of 1 cm.

[0056] Note that this dimension allows control over the wood surface wetted by the liquid as well as over the mass transfer process, which regulates the chemical and physical evolution of the product. According to the Applicant, the use of chips of variable size does not allow the process to be estimated and controlled as efficiently as the use of cubes.

[0057] The Applicant noted that reactions carried out in the presence of wood cubes lead to organoleptic variations that are better than those carried out with chips. In the presence of chips, in fact, during the reaction it is observed that the colour rapidly becomes cloudy and dark, and less pleasant and persistent off-flavours develop.

[0058] Preferably, the wood chips or cubes are made of a wood used for barrel production. It should be noted that the wood is the one used to make traditional casks, coming from the innermost part of the tree trunk, an area particularly rich in chemical compounds needed for maturation. Preferably, the wood used to produce the barrels is selected from the group consisting of: oak wood; durmast wood; ash wood; preferably barrel wood previously in contact with cognac, barrel wood previously in contact with whisky, barrel wood previously in contact with bourbon, barrel wood previously in contact with sherry, barrel wood previously in contact with port; and mixtures of the above.

[0059] Preferably, the wood chips or cubes have undergone burning or scorching, also technically referred to as charring. Preferably, the wood chips or cubes undergo a controlled burn.

[0060] Note that charring and roasting are two different processes. In the former, the wood is burnt and complete combustion takes place; furthermore, through charring, surface temperatures well above 100°C are reached, since open flames are used on the wood. In the second, the wood is only heated to a high temperature, without any flame; note that temperatures close to or below 100 / 120°C lead to a toasting that is somewhere between light and medium.

[0061] It is well known that the heat treatment which wood chips or cubes are subjected to has an impact on the type of compounds that can be extracted from the distillate during the process.

[0062] The Applicant empirically appreciated that better results, e.g. in organoleptic terms, could be achieved by controlled burning than by roasting.

[0063] Controlled or light burning refers to a process wherein fire is set to wood chips or cubes, e.g. using a blowpipe. The burnt part is exposed to the flame for a defined time, preferably between 10 and 15 seconds, then the flame is removed.

[0064] Preferably, the wood chips or cubes were pre-treated with ethanol, preferably they were soaked in pure ethanol for a time between 12 and 24 hours, preferably 24 hours.

[0065] Preferably, the mass of wood chips or cubes is between 10 and 55 g, preferably between 12 and 50 g, preferably between 14 and 48 g, per litre of distillate.

[0066] Preferably, the surface area of the wood chips or cubes is between 70 and 500 cm2, preferably between 74 and 450 cm2, preferably between 79 and 400 cm2, preferably between 79 and 350 cm2, preferably between 79 and 315 cm2, preferably between 79 and 270 cm2, preferably between 79 and 240 cm2, preferably between 79 and 200 cm2, preferably between 79 and 195 cm2, preferably between 79 and 189 cm2, preferably between 79 and 155 cm2, preferably between 79 and 115 cm2, preferably between 79 and 90 cm2, preferably between 79 and 87 cm2, per litre of distillate (also referred to as the S / V ratio).

[0067] The Applicant noted that for S / V values above 100 cm2per litre of distillate, better organoleptic results are obtained.

[0068] According to a particularly preferred embodiment, the surface area of the wood chips or cubes is between 180 and 500 cm2, preferably between 190 and 500 cm2, preferably between 190 and 300 cm2, preferably between 190 and 270 cm2; still preferably between 250 and 500 cm2, preferably between 300 and 500 cm2, preferably between 400 and 500 cm2, per litre of distillate.

[0069] Ultrasound source

[0070] For the purposes of the invention, ultrasound source means either an ultrasound bath or an ultrasound generator, both of which are instruments known to a person skilled in the art.

[0071] The process of the invention advantageously uses at least one ultrasound source (US) to speed up and increase the yield of the spirits distillate maturing process. In particular, due to the effect of cavitation, the surface of the wood fractures (on a microscopic level), greatly increasing the contact surface available, particularly between the solvent (non-matured distillate) and the solid (wood chips or cubes). This leads to an increase in the diffusive flow of the compounds from the wood to the distillate. In addition, the cavitation process leads to significant increases in local temperature and pressure, which considerably increase the yield of oxidation reactions responsible for the production of various compounds characterising the organoleptic profile of the end product.

[0072] It should be noted that carrying out sonication in the absence of at least one source of wood, e.g. wood in the form of chips or cubes, has a negative impact on the qualities of the product, mainly on its organoleptic properties. Preferably, in order to avoid contact between the ultrasound source and the wood in the form of chips or cubes, the distillate is placed in a chamber positioned close to the ultrasound source. Stirring the chamber is considered to result in the mixing of the distillate.

[0073] Preferably, for the batch or semi-continuous process, the at least one ultrasound source is at least one ultrasound bath.

[0074] Preferably, the process of the invention modulates the organoleptic profile of the end product, preferably of the following chemical compounds: Syringic acid, Vanillin, Syringaldehyde, Coniferyl aldehyde, Gallic acid, Vanillic acid.

[0075] Ultrasounds are provided at preset time intervals, alternating between moments of operability / activity / operation (ON period) and moments of pause / rest / non-operation (OFF period). In this sense, we refer to sonication cycles. This prevents overheating of the product.

[0076] One sonication cycle corresponds to the sum of the operation time “ON” and of the rest time “'OFF”.

[0077] Preferably, in step d) of operating the at least one ultrasound source and allowing the distillate to age, the number of operating-rest cycles of the at least one ultrasound source is between 200 and 5000, preferably between 200 and 4800, preferably between 200 and 4500, preferably between 200 and 4000, preferably between 200 and 3800, preferably between 200 and 3500, preferably between 200 and 3000, preferably between 400 and 3000, preferably between 500 and 3000, preferably between 700 and 3000, preferably between 800 and 3000, preferably between 1000 and 3000, preferably between 2000 and 3000.

[0078] Preferably the number of operating-rest cycles of the at least one ultrasound source is between 200 and 750, preferably between 200 and 740, preferably between 200 and 600, preferably between 200 and 500, preferably between 200 and 400, preferably between 200 and 370, preferably between 210 and 370, preferably between 220 and 370. The Applicant noted a further improvement in process efficiency when the number of operating-rest cycles of the at least one ultrasound source exceeds 400.

[0079] According to a preferred embodiment, in step d) of operating the ultrasound source and allowing the distillate to age, the number of operating-rest cycles of the at least one ultrasound source is between 400 and 4200, preferably between 500 and 4000, preferably between 500 and 3000, preferably between 500 and 2300 cycles, preferably between 500 and 2000, preferably between 500 and 1500, preferably between 800 and 1500.

[0080] It should be noted that preferably higher sonication cycles than those indicated have a negative impact on process efficiency and economy.

[0081] Preferably, in step d) of operating the ultrasound source and allowing the distillate to age, at least one operating-rest cycle of the at least one ultrasound source provides for an operating time “ON” of between 1 and 8 minutes, preferably between 1 and 6 minutes, preferably between 1 and 5 minutes, preferably between 1 and 4 minutes, preferably between 1 and 3 minutes preferably of 1 or 3 minutes. Still preferably, the operating time “ON” is between 2 and 8 minutes, preferably between 3 and 8 minutes, preferably between 3 and 6 minutes.

[0082] Note that compared to known processes, for which the sonication operating period “ON” is > 15 minutes, the operating times “ON” of the invention are advantageously shorter. This results in a more efficient and cheaper process, achieving an equal or better organoleptic profile.

[0083] It should be noted that higher operating times (ON), other than those of the invention, e.g. > 15 min, resulted products non-compliant from an organoleptic perspective.

[0084] Preferably, the rest time is between 2 and 10 minutes, preferably between 2 and 8 minutes, preferably between 3 and 7 minutes, preferably between 4 and 6 minutes.

[0085] The Applicant considers that the OFF or rest period of the ultrasound source is a time necessary only to bring the “distillate and wood” system back to an optimal temperature before proceeding with the next ultrasound cycle. In other words, OFF times do not have an organoleptic impact; for the purposes of the invention, rest times OFF were preferably prolonged to mitigate the effect of increased temperature. Furthermore, in the absence of an adequate cooling system, given the significant temperature increases caused by the sonication process, the system would take a long time, following treatment, before returning within an acceptable thermal range.

[0086] Preferably, the frequency at which the ultrasound source operates is between 30 and 50 kHz, preferably between 32 and 47 kHz, preferably between 35 and 45 kHz, preferably between 35 and 40 kHz preferably of 40 kHz.

[0087] Preferably, the operating power of at least one ultrasound source is between 100 and 150 W, preferably between 120 and 140 W, preferably between 130 and 140 W, preferably of 130 W per litre of distillate.

[0088] Note that the power of the ultrasound source is a function of the volume of distillate treated.

[0089] Preferably, the ultrasound application time is between 2,000 and 20,000 minutes, preferably between 2,000 and 18,000, preferably between 2,000 and 15,000, preferably between 2,000 and 10,000, preferably between 2,000 and 8,000 minutes, preferably between 2,000 and 5,000 minutes, preferably between 2,000 minutes and 3,800 minutes, preferably between 2,000 minutes and 3,800 minutes, preferably between 2,000 and 3,350, preferably between 2,000 and 3,320 minutes.

[0090] Oxygenation

[0091] Oxygenation contributes to successful ageing. The amount of oxygen within the system can be regulated, allowing more control over the reaction yield.

[0092] It should be noted that the maturation process does not only consist of the lignin ethanolysis process, which is speeded up by the use of ultrasounds, nor does it only consist of the material diffusion that carries the compounds “released” by the ethanolysis reaction from the wood to the solvent; in this sense, oxidation plays a role contributing to the quality of the finished product.

[0093] For example, oxygenation is managed by pumps that regulate the air flow.

[0094] The oxygenation flow used is between 0.5 and 5 ml / min, preferably between 1 and 4 ml / min. Preferably, the oxygenation flow is used for a time that makes it possible to insufflate an amount of air between 150 and 300 ml per day for the duration of the process.

[0095] According to a preferred embodiment, oxygenation occurs only through the headspace within the system. In other words, no additional oxygen is insufflated via the pumps.

[0096] Preferably, oxygenation is not performed at the same time as sonication, as an adverse effect of ultrasounds on the solubility of oxygen in the hydroalcoholic solution has been highlighted.

[0097] Temperature

[0098] Temperature control is essential in order to avoid heat variations and the development of off-flavours due to Maillard reactions. Temperature control is therefore a critical factor. This parameter is usually roughly controlled, e.g. by keeping the temperature constant at around 25 °C. This temperature, kept constant, is far too high to obtain a product that is specific in terms of both colour and organoleptic characteristics.

[0099] In the case of the invention, the temperature is between 0 °C and 40 °C, preferably between 0 °C and 35 °C, preferably between 5 °C and 35 °C, preferably between 10 °C and 30 °C, preferably between 10 °C and 35 °C, preferably between 10 °C and 25 °C, preferably between 12 °C and 25 °C, preferably between 12 °C and 20 °C, preferably between 15 °C and 20 °C. It is thus possible to immediately affect the colour or yield of the extraction.

[0100] According to a preferred embodiment, it is possible to operate with temperature “ramps”, e.g. the sample to be treated is kept at a temperature between 10 and 15 °C for 12 hours, then raised to 35 °C for the next 12 hours.

[0101] Preferably, the temperature is controlled by a recirculation system connected to a heat exchanger. More preferably, the temperature is controlled by temperature control means comprising: at least one heat exchanger, a coolant comprising a cooling mixture, e.g. comprising water and glycol, at least one pumping means.

[0102] A person skilled in the art knows cooling mixtures capable of lowering the freezing point of the system. For the purposes of the invention, the mixture (or solution) comprising water and glycol was selected for its low cost and safety of use. Preferably, the mixture of water and glycol has a waterglycol ratio between 60:20 and 80:40, preferably 70:30.

[0103] It is thus possible to modulate the flow rate of the coolant to have maximum control over the temperature of at least one ultrasound source. The temperature control means comprise at least one recirculation means that allows to control the temperature of the extraction process and consequently the yield. This temperature control means impacts the quality of the end product and the yield of the maturation process. This control system can be used in both batch and semi-continuous or continuous processes.

[0104] Preferably, the process of the invention takes place in a period of time between 3 and 60 days, preferably between 3 and 40 days, preferably between 3 and 30 days, preferably between 7 and 30 days, preferably between 7 and 20 days, preferably between 7 and 16 days, preferably between 8 and 12 days, preferably between 3 days or 5 days or 10 days or 16 days or 30 days.

[0105] Preferably, the process of the invention may be carried out in batch or semi-continuous or continuous conditions. Note that the parameters or means (wood chips or cubes, ultrasound source, oxygenation, temperature) described so far are valid independently of whether the process is carried out in batch, or semi-continuous, or even continuous conditions.

[0106] Batch process

[0107] The batch process corresponds to an ageing process on a laboratory scale.

[0108] Preferably, the process is carried out in batch conditions, the at least one reactor comprises or consists of a container, preferably a reaction flask, hermetically closed (or sealed), in the presence of

[0109] - oxygen already present in the reactor before the addition of the distillate (oxygen present in the “headspace” of the flask), and / or

[0110] - oxygen introduced into the reactor by pumping systems or means.

[0111] Preferably, the at least one source is at least an ultrasound bath.

[0112] Preferably, the process carried out in batch conditions comprises the following steps: a) preparing: at least one reactor, preferably a reaction flask, wood chips or cubes, at least one ultrasound source or bath, at least one distillate to be submitted to ageing, preferably pumping means, preferably temperature control means, b) inserting the wood chips or cubes into at least one reactor together with the distillate, c) inserting the at least one reactor prepared in step (b) above into the at least one ultrasound bath, and d) operating the ultrasound bath and allowing the distillate to age.

[0113] When oxygen is present in the headspace, this is considered to be sufficient to proceed with the oxidation reactions necessary to achieve the required physical-chemical characteristics. Therefore, in this case, there is no actual oxygenation system: the air needed for the chemical reactions to proceed is the air inside the reaction flask, once it is closed, together with the wood c / vi / rs / cubes and the distillate. The tightness of the flask cap ensures that the product does not come into contact with other air, thus preventing excessive oxidation of the product which would affect its organoleptic properties and / or colour and / or product yield.

[0114] It should be noted that several prior art systems either do not have a true oxygenation control system or do not operate in a completely closed system (e.g. the tank containing the distillate may be open), thus not controlling the oxygenation of the distillate during ageing.

[0115] When oxygen is preferably introduced by pumping means, such as an air pump, it should be noted that the headspace inside the flask is minimal; in particular, the air required for the completion of the ageing process is insufflated by a tube from the air pump that ends at the bottom of the flask. Thus, as the air bubbles rise, the necessary oxygen is supplied to the system. Preferably, a small hole is also made in the container to avoid pressure gradients due to air entering the system.

[0116] Semi-continuous or continuous process

[0117] Preferably, the semi-continuous (also called “non-stagnant batch” ) or continuous process corresponds to an ageing process operated in more complex systems than the one in the laboratory, or in industrial plants. Preferably, the volume flow rate is between 0.5 and 3 mL / min, preferably between 1 and 2 mL / min, preferably of 1 mL / min.

[0118] Preferably, the process is carried out in semi-continuous or continuous conditions, the at least one reactor is at least one stainless steel tube, the process being carried out in the presence of oxygen introduced by pumping systems or means, preferably said pumping systems or means comprising at least one air pump and / or at least one liquid pump.

[0119] Preferably, when at least one reactor is > 1, each reactor can be interspersed with the next by heat exchangers to maintain thermal control and avoid excessive heating due to the presence of ultrasound.

[0120] Preferably, the semi-continuous or continuous process comprises the following steps: a) preparing: at least one stainless steel tube as a reactor,

[0121] - wood chips or cubes, preferably wood cubes, at least one ultrasound source,

[0122] - the distillate to be submitted to ageing, preferably the distillate is contained in a tank, and / or preferably means selected from the group consisting of: pumping means, preferably an air pump and / or a peristaltic pump; connecting means; recirculation means; filtering means; distillate containment means (such as a tank); temperature control means; and combinations of the above, b) introducing the wood chips or cubes into at least one stainless steel tube together with the distillate, preferably the latter introduced by pumping means, c) inserting or connecting the at least one stainless steel tube into or to the at least one ultrasound source, d) operating the at least one ultrasound source and allowing the distillate to age.

[0123] Preferably, in the semi-continuous or continuous process, wood cubes, carved wooden cubes are used to maximise the S / V ratio. Preferably, oxygenation is in this case controlled by pumping means, preferably an air pump, which circulates air within the distillate containment means, preferably in the tank (or “buffer tank”).

[0124] It should be noted that the filter means allow to simultaneously protect the pumping means from any solid wood residues that might affect it, and to mitigate the effect that these solid residues have on the colour of the end product.

[0125] Preferably, the connecting means consist of tubing made of an inert, flow-resistant material, preferably PTFE. Note that PTFE is a safer material than silicone or other materials equivalent to silicone.

[0126] Preferably, the at least one stainless steel tube is made of stainless steel selected from the group consisting of: AISI 316 stainless steel (for food use), AISI 304 stainless steel, and mixtures of the above.

[0127] Preferably at least one stainless steel tube has the following dimensions: length preferably between 3 and 7 cm, preferably of 5 cm; inner radius preferably between 2 and 6 cm, preferably of 4 cm.

[0128] A person skilled in the art knows the types of stainless steel that can be used as an alternative to the above in the food industry.

[0129] It should be noted that the use of a stainless steel tube over a glass one is advantageous; in fact, steel has very different physical properties to glass and this has a drastic impact on both heat dissipation and on propagation of ultrasounds therein, and consequently on the process yield and quality of the end product.

[0130] Preferably, the flow rate of the fluid (distillate) is between 3 and 10 1 / h, preferably between 4 and 8 1 / h, preferably between 4 and 6 1 / h, preferably is of 6 1 / h. Preferably, the at least one stainless steel tube has a length of at least 15 cm.

[0131] Preferably, the at least one ultrasound source is at least one ultrasound bath, wherein the at least one stainless steel tube is preferably inserted.

[0132] Preferably, the number m of the at least one ultrasound source is numerically equal to the number n of the at least one steel tube. Preferably, each ultrasound source includes at least one steel tube; said “reactor and ultrasound source” configuration constitutes a module. Each module is preferably arranged in series.

[0133] Preferably, the number n of the at least one steel tube is > 2, and the tubes are connected in series.

[0134] Preferably, wood cubes from the same or different wood sources can be used within a single module or in several modules.

[0135] Preferably, the operating conditions of temperature, ultrasound and residence time can be varied for each module.

[0136] The semi-continuous process provides that the distillate, which is in a hermetically sealed (watertight) tank or lung, is introduced by special pumping means, preferably a liquid or peristaltic pump, into a stainless steel tube. In the semi-continuous process, the fluid (distillate) is made recirculate inside a stainless steel tube filled with cask wood cubes. The tube is immersed inside the ultrasound bath.

[0137] Preferred embodiment o f the continuous process

[0138] It should be noted that, compared to the semi-continuous process, the continuous process does not provide fluid recirculation means. In addition, air is preferably insufflated into the system directly continuously.

[0139] Preferably, the continuous process comprises the following steps: b) preparing: at least one stainless steel tube as a reactor,

[0140] - wood chips or cubes, preferably wood cubes, at least one ultrasound source, at least one containment tank for industrial use,

[0141] - the distillate to be submitted to ageing, preferably this is contained in a tank, and / or preferably means selected from the group consisting of: pumping means, preferably an air pump and / or a peristaltic pump; connecting means; filtering means; distillate containment means (such as a tank); temperature control means; and combinations of the above, b) introducing the wood chips or cubes into at least one stainless steel tube together with the distillate, preferably the latter introduced by pumping means, c) connecting the at least one stainless steel tube to the at least one ultrasound source, then inserting the at least one stainless steel tube into the containment tank, d) operating the at least one ultrasound source and allowing the distillate to age.

[0142] An example of a containment tank for industrial use is a tank with dimensions 3 m x 1 m x 1 m.

[0143] Preferably, the at least one ultrasound source is an ultrasound generator connected with the at least one reactor or stainless steel tube.

[0144] Preferably, for the continuous process, the length of the at least one stainless steel tube is between 10 and 20 metres ( / ??), preferably between 15 and 20 metres, preferably between 18 and 20 metres.

[0145] Preferably, the continuous process provides that the distillate, which is in a hermetically sealed (watertight) tank or lung, is introduced by special pumping means, preferably a liquid or peristaltic pump, into the stainless steel tube. The fluid (distillate) circulates inside the stainless steel tube, and is filled with wooden cubes, immersed in the containment tank and connected to at least one ultrasound generator.

[0146] Plant for improving the efficiency of a spirits distillate ageing

[0147] Preferably, the process is carried out in a plant, preferably a semi-continuous or continuous plant, for making the ageing process of a spirits distillate more efficient comprising:

[0148] - at least one reactor, preferably one reactor or at least two reactors arranged in series,

[0149] - at least one ultrasound source, preferably the source being an ultrasound bath, preferably there is at least one ultrasound source for each reactor,

[0150] - temperature control systems or means,

[0151] - pumping systems or means to convey the distillate to at least one reactor,

[0152] - pumping systems or means to introduce the oxygen into at least one reactor, - optionally, connecting means, preferably to connect at least two reactors arranged in series with each other,

[0153] - optionally, temperature control means.

[0154] Note that, following the diagram in Figure 20, each at least one ultrasound source comprises at least one reactor “packed” with wooden cubes, thus constituting a module of the system. Preferably, the module can repeat itself a number z of times, preferably z is > 2, preferably between 2 and 7.

[0155] According to an alternative preferred embodiment, the plant operating continuously the process for improving the efficiency of a spirits distillate ageing comprises:

[0156] - at least one reactor, preferably at least two reactors,

[0157] - at least one ultrasound source,

[0158] - at least one containment tank for industrial use,

[0159] - temperature control systems or means,

[0160] - pumping systems or means to convey the distillate to at least one reactor,

[0161] - pumping systems or means to introduce the oxygen into at least one reactor,

[0162] - optionally, connecting means, preferably to connect the reactors and / or to connect the at least one reactor and the at least one ultrasound source,

[0163] - optionally, temperature control means.

[0164] Note that the connecting means and / or temperature control means are as described above.

[0165] EXAMPLES

[0166] The Applicant provides the hereinafter examples for illustrative and non-limiting purposes.

[0167] Definitions

[0168] The definitions of the terms used in Examples 1, 2, 3 and 4 are reported below.

[0169] • Sample: indicates the unique code assigned to the sample; • ABV (Alcohol by volumey. the amount of alcohol present in the solution expressed as the ratio of the volume of ethanol to the volume of solution;

[0170] • Type of Wood, indicates the type of wood used in the production of the sample. This can be “wood cubes” if cubes recovered from the planks that make up the casks wherein maturation normally takes place have been used, or wood “chips” if they are wood shavings of the same origin; specifically, for the cubes, the cask wood has been carved into parallelepipeds with a base area of 0.5 x 0.5 x 1 cm;

[0171] • Wood (or origin of the wood): indicates which product was previously matured in that cask;

[0172] • Volume (ml): indicates the volume of liquid used to prepare the samples;

[0173] • Charring or roasting: indicates whether or not the heat treatment referred to as “charring” has been performed. This treatment consists of a controlled burning of the wood;

[0174] • US ultrasound time', this parameter consists of two numbers, the first indicates the active time, i.e. the time during which ultrasounds are being used, while the second indicates the rest time, i.e. the time during which ultrasounds are not being used between one sonication cycle and the next;

[0175] • Pre-treatment'. this parameter indicates whether or not “pre-treatment” was performed, this consists of soaking the wood in pure ethanol for 24 hours;

[0176] • Surface / Volume S / V: this parameter indicates the ratio between the contact surface of the wood and the volume of liquid present in solution;

[0177] • Oxygenation O2. this parameter indicates whether an additional oxygenation process was performed. If the parameter is “no”, it means that the product was only oxygenated by the headspace within the system;

[0178] • Temperature ( °C): indicates the maximum and minimum temperature values at which speeded ageing was performed. If only one value is present, it means that the process was carried out under isothermal conditions at the indicated temperature; • Sonication Time (minutes): indicates the total sonication treatment time the sample was submitted to. This value corresponds to the sum of all active minutes.

[0179] Example 1 - Study of the effectiveness of the process of the invention, operating in batch.

[0180] Aim:

[0181] The aim is to show and analyse the results obtained from the chemi cal -physical analyses carried out to demonstrate the effectiveness of the rapid ageing method using ultrasounds for spirits.

[0182] Materials and methods

[0183] HPLC

[0184] The concentration of the above-mentioned compounds in the aged product by sonication was determined by high-performance-liquid-chromatography (HPLC). The specifications of the machinery used are as follows: the column is a Roc C18 (250 mm x 4.6 mm x 5 pm), the pump is a PU 2089-plus, the ultraviolet detector is a (UV) dial PDA detector MD-2018 and the oven is a CO-2060-plus.

[0185] The machine uses mobile phases that slide inside the column. The difference in affinity between the different compounds and the eluents used to move the sample through the system results in different output times of the compounds and generates a chromatogram in which each peak is uniquely linked to a certain retention time and consequently uniquely associated with a certain compound previously identified by means of standard samples. Standard samples were prepared by dissolving known amounts of the pure compound in a 50% solution of water and ethanol. Using three reference concentrations for each standard compound, it was possible to calibrate the machine and determine the ppm concentration of the compounds by integrating the areas subtended by the peaks shown in the chromatogram.

[0186] The eluents used are:

[0187] • A: acetonitrile

[0188] • B: solution of 98% water and 2% acetic acid D: solution of 70% methanol 29% water 1% acetic acid

[0189] The ramp has a duration of 55 minutes and involves alternating eluents in order to facilitate the differentiated output of the different compounds.

[0190] Ultrasound source The machine used to supply ultrasounds to the system is a Branson 2510 with a maximum power of 130 W and a frequency of 40 kHz. Ultrasound in contact with cask wood generates locally high pressure and temperature gradient points. These gradients promote oxidation and hydrolysis reactions that cause the formation of the compounds sought during maturation. In addition, air bubbles cavitating in contact with the wood generate shock waves capable of creating surface cracks in the wood, which significantly increase the available contact surface area, and consequently speed up the material diffusion processes underlying the ageing process.

[0191] The characterisation of the different samples according to the method by which they were prepared are set forth hereinafter (see Tables 1A and IB below).

[0192] Table 1A

[0193] Table IB

[0194] The results for the organoleptic compounds analysed and obtained for each sample treated under the operating conditions in Tables 1 A and IB are shown below and in the corresponding Figures 1-16. G-000 - 45%> ABV

[0195] Table 1C

[0196] G-100 - 63%> ABV

[0197] Table ID G-200 - 63%> ABV G-300 - 63% ABV

[0198] G-400 - 63%> ABV

[0199] Table 1G G-500 - 63%> ABV

[0200] Table 1H

[0201] G-600-63%ABV

[0202] Table II

[0203] G-700-63%ABV Table IL G-800-63%ABV

[0204] Table IM

[0205] G-900-63%ABV

[0206] Table IN M-000-63%ABV

[0207] Table 10 M-100 -63%ABV

[0208] Table IQ M-300-63%ABV

[0209] Table 1R

[0210] M-400 - 63% ABV

[0211] M-500 - 63% ABV Table IT

[0212] Data discussion

[0213] The data reported in Figures 1-16 clearly show a positive trend. The concentration profile, which resembles a logarithmic behaviour for some samples, shows a rapid development of fairly high concentrations in the first maturation cycles, and then continues to grow with a positive trend, but characterised by a smaller slope. This is similar to what happens naturally during traditional ageing, whereby most of the compounds and aromatic profile is developed during the first 2 / 3 years of maturation, while the years of ageing that follow are mainly used as refinement to soften the taste of the end product and give it depth and complexity.

[0214] The reference values used for the comparisons were obtained by performing the same analyses on a number of commercial whiskies that share some common aspects in terms of production method.

[0215] Table 2 below shows the average concentration values of the analysed compounds:

[0216] Table 2

[0217] Regarding colour, which was not analysed using analytical instruments, this shows a progressive increase in amber colouration from the very first cycles. The difference in colouring during the different steps is so obvious that it can be observed with the naked eye (see Figure 17).

[0218] Conclusions

[0219] The method used to speed up the ageing of spirits proved to be effective and efficient. The data collected from the analysis show that the samples reach values comparable with commercial products after about 3,000 minutes of sonication, and the positive trend exhibited by the data analysis suggests that it is possible to push the reaction further so as to extract the compounds to the specific concentrations of the commercial standards.

[0220] Example 2 - Study of the effectiveness of the process of the invention, operating in flow.

[0221] The flow tests were carried out starting from the operating conditions that allowed, in the case of the batch system, to obtain the most promising samples. In particular, it was decided to use a 63% ABV hydroalcoholic solution.

[0222] Note that the materials and methods used are the same as those in Example 1 operating in batch. The definitions of the terms used in Tables 2A and 2B are given in the same Example 1.

[0223] Flow tests can be carried out with the first configuration in Figure 21, in which the IN and OUT streams are not present and the tank acts as an external buffer.

[0224] The tests were carried out using 0.5 x 0.5 x 1 cm parallelepipeds of wood, pre-treated with an open flame charring. All tests used an external lung containing 1 L of solution. The ultrasonication cycles were timed at 6 min ON and 3 min OFF (the thermal runaway was controlled via an external chiller, to maintain the temperature around 10 °C) for a total test duration of 30 days.

[0225] The sample obtained was analysed by a certified sommelier in a blind tasting comparing it with other industrial samples, obtaining good evaluations and comparable with a 5-year cask-matured sample.

[0226] Table 2A

[0227] Table 2B HPLC analyses were performed to assess the concentration profiles of the main species (syringic acid, vanillin, syringaldehyde, coniferyl aldehyde, gallic acid, vanillic acid) at different ageing times. Specifically, analyses were carried out every 10 days, leading to the results shown in Table 2C below (concentrations in ppm). Table 2C

[0228] Example 3 - Study of the effectiveness of the process of the invention at high sonication cycles.

[0229] This test was carried out as a comparison with the flow test as for Example 2.

[0230] Note that the materials and methods used are the same as those in Example 1 operating in batch. The definitions of the terms used in Tables 3 A and 3B are given in the same Example 1.

[0231] The operating conditions are summarised in the tables below:

[0232] Table 3A

[0233] Table 3B

[0234] The 4800 min sonication time corresponds to a test with 800 sonication cycles. The quantifications by HPLC and their results are summarised in Table 3C below.

[0235] Table 3C

[0236] The profile obtained shows gradually increasing results for the various species analysed, as already noted in the batch tests. In tests with prolonged sonication cycles, the initial stretch is comparable with classical tests, thus noting a continuous increase in concentrations and thus the ageing of the sample, thus being able to compare it to a sample aged for several years.

[0237] Example 4 - Comparative study where sonication times ON are longer than 8 minutes.

[0238] The Applicant noted that a sonication time ON > 15 minutes leads to products that are non-compliant from an organoleptic perspective.

[0239] The test carried out at increased sonication times was performed keeping the same total time selected for flow tests (30 days). This configuration was selected because, with the use of an external heat exchanger, it was easier to control the system temperature.

[0240] Note that times close to or greater than 15 minutes do not allow the outside temperature to be controlled and there is always a warming of the system. In particular, it has been noted that the increase in temperature causes an increase in the oxidation kinetics of aldehydes to carboxylic acids (thus increasing the concentration of the latter with respect to the former), affecting the organoleptic and colour properties.

[0241] The temperature range (15-30 °C) was increased to take into account the actual increase after prolonged use of ultrasounds. In addition, the rest time OFF was also increased in order to try to bring the temperature back to the initial value.

[0242] Table 4A

[0243] Table 4B

[0244] Table 4C

[0245] REFERENCES 1. Study of a laboratory-scaled new method for the accelerated continuous ageing of wine spirits by applying ultrasound energy - M. J. Delgado-Gonzalez, M.M. Sanchez- Guillen, M.V. Garcia-Moreno, M.C. Rodriguez-Dodero, C. Garcia-Barroso, D.A. Guillen-Sanchez - Ultrasonic Chemistry (2016) http : / / dx . doi . org / 10.1016 / j.ultsonch.2016.11.031; 2. Development of an accelerated aging method for Brandy Monica Schwarz a. M.

[0246] Carmen Rodriguez, Manuel Sanchez, Dominico A. Guillen, Carmelo G. Barroso - LWT - Food Science and Technology 59 (2014) http: / / dx.doi.Org / 10.1016 / j.lwt.2014.05.060;

[0247] 3. Effect of ultrasound irradiation on the evolution of colour properties and major phenolic compounds in wine during storage Qing-An Zhang, Ting-Ting Wang Food Chemistry 234 (2017) - http: / / dx.doi.Org / 10.1016 / j.foodchem.2017.05.022; 4. Use of ultrasound at a pilot scale to accelerate the ageing of sherry vinegar - Maria Jimenez-Sanchez, Enrique Duran-Guerrero, M. Carmen Rodriguez-Dodero, Carmelo G. Barroso, Remedios Castro- Ultrasonics-Sonochemistry 69 (2020) https: / / doi.Org / 10.1016 / j.ultsonch 2020. 105244.

Claims

CLAIMS1. Process for improving the efficiency of a spirits distillate ageing comprising the following steps: a) preparing: at least one reactor, wood chips or cubes, at least one ultrasound source, a distillate to be submitted to ageing, b) introducing the wood chips or cubes and the distillate into the at least one reactor, c) inserting the at least one reactor prepared in the previous step into the at least one ultrasound source, and d) operating the ultrasound source and allowing the distillate to age, wherein in step a) of preparing at least one reactor, wood chips or cubes, at least one ultrasound source, a distillate to be submitted to ageing, wood chips or cubes whose surface area is between 70 and 500 cm2per litre of distillate are used, step d) of operating the at least one ultrasound source and allowing the distillate to age is carried out:- in the absence of light,- at a temperature between 0 °C and 40 °C,- with a number of operating-rest cycles of at least one ultrasound source between 200 and 4500.

2. Process according to claim 1, wherein the ABV index of the distillate is between 45% and 67%.

3. Process according to claim 1 or 2, wherein the wood chips or cubes are made from a wood used for barrel production.

4. Process according to any one of claims 1 to 3, wherein the wood chips or cubes have undergone combustion.

5. Process according to any one of claims 1 to 4, wherein the wood chips or cubes have undergone a pretreatment with ethanol.

6. Process according to any one of claims 1 to 5, wherein the concentration of wood chips or cubes is between 10 and 55 g per litre of distillate.

7. Process according to any one of claims 1 to 6, wherein the operating power of the at least one ultrasound source is between 100 and 150 W per litre of distillate.

8. Process according to any one of claims 1 to 7, wherein the frequency of the at least one ultrasound source is between 30 and 50 kHz.

9. Process according to any one of claims 1 to 8, wherein, in the step d) of operating the at least one ultrasound source and allowing the distillate to age, the at least one operating-rest cycle of the at least one ultrasound source comprises an operating time of between 1 and 8 minutes; preferably, the rest time is between 2 and 10 minutes.

10. Process according to any one of claims 1 to 9, being carried out in batch or semi- continuous or continuous conditions.

11. Process according to claim 10, wherein the process is carried out in batch, the at least one reactor comprises or consists of a hermetically sealed container, in the presence of oxygen already present in the reactor prior to the addition of the distillate, or introduced into the reactor with pumping systems, and wherein the at least one source is an ultrasound bath.

12. Process according to claim 10, wherein the process is carried out in semi- continuous or continuous conditions, the at least one reactor is at least one stainless steel tube, the process being carried out in the presence of oxygen introduced by pumping systems, preferably said pumping systems comprising at least one air pump.

13. Process according to claim 12, wherein the at least one stainless steel tube is made of stainless steel selected from the group consisting of: stainless steel AISI 316, stainless steel AISI 304, and mixtures of the above.

14. Process according to claim 12 or 13, wherein the number n of the at least one steel tube is > 2, and the tubes are connected in series.

15. Process according to any one of claims 12 to 14, wherein the number m of the at least one ultrasound bath is numerically equal to the number n of the at least one steel tube.

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