A process for preparing a wort

Abstract

A process for preparing a VHG wort comprising: (a) providing a composition having a water:grist ratio of 2.4:1 or less and comprising weak wort and, optionally, β-glucanases and / or xylanases; (b) mash

Description

INTRODUCTION The present invention relates to a process for preparing a very high gravity (VHG) wort, to related processes also comprising certain additional steps, and to products of the processes. BACKGROUND In the preparation of an alcoholic beverage, the brewhouse refers to the process steps prior to the step of fermentation. Key steps in the brewhouse include mashing, filtering, sparging, and boiling. In the mashing step, a composition having a certain water to grist ratio is mashed during a sequence of temperature rises and rests defined by a so-called brewing diagram. A purpose of this step is to facilitate saccharification, which produces sugars suitable for eventual fermentation. In the filtering step, the mashed composition is separated into first wort and a filter cake. The first wort forms part of a pre-boil wort to be carried forward to the boiling step. During sparging, the filter cake is washed to further extract wort and reduce the amount of material left in the filter cake. With increasing sparging volume, the filtrate becomes increasingly weaker as the amount of material extracted from the filter cake gradually reduces. In the boiling step, the pre-boil wort is boiled, for example with hops, with a view to imparting flavour. The wort so-obtained can then be carried forward for fermentation. The provision and heating of large volumes of water at various stages of the brewhouse has a negative economic and environmental impact. There is therefore a desire to reduce these impacts by exploiting a more economical and environmentally-friendly brewhouse process. Such a process can be characterised by the use of reduced volumes of water and thus reduced associated energy inputs. The present invention therefore provides a higher gravity brewhouse process which produces a very high gravity (VHG) wort. SUMMARY Viewed from a first aspect, the present invention provides a process for preparing a very high gravity (VHG) wort having a gravity of at least 18 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio of 2.4:1 or less and comprising weak wort; b) mashing the composition provided in step (a) to provide a mashed composition; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of at least 16 °P, a filter cake, and a weak wort; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of at least 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 23.5 °P. DEFINITIONS As used herein, the term “WTGR” is used equivalently with the terms “water to grist ratio”, “watergrist ratio” or “w:g ratio”. All refer herein to a ratio of the total mass of grist to the total volume of water in a given stage of a brewhouse process, for example in a vessel at a given stage of a brewhouse process. Such a ratio is given in units of L / kg, unless specified otherwise. The calculation of WTGR is known to those skilled in the art. Grist includes malt, cereal, and grains, where grist may for example be milled. Water includes foundation water, flush water, and mashing-in water. The water may comprise or consist of weak wort. As used herein, “gravity” is measured in units of degrees Plato (°P), unless specified otherwise. Means of measurement will be known to the skilled person. Gravity is related to the density or strength of a particular composition in the brewhouse process. As used herein, the term “RDF” is used equivalently with the term “real degree of fermentation”. RDF refers to the mass % degree to which extract, which includes carbohydrates and e.g. protein, in a wort is converted to alcohol in a fermentation step. RDF will be linked to factors such as the relative amounts of fermentable and non-fermentable sugars in a wort, and the rate of fermentation. As used herein, the term “weak wort” refers to a product of a sparging step in a brewhouse process. Weak wort differs from “pre-boil” wort in having a lower gravity. Preboil wort is carried forward to a boiling step, whereas weak wort is not. As used herein, the term “first wort” refers to wort produced in a filtration step, prior to any sparging. The filtration may be performed using a lauter tun or mash filter. First wort forms part of the pre-boil wort. The remaining part of the pre-boil wort is derived from the sparging step. As used herein, the term “mashing-off” or equivalently “mash-off’ refers to the conditions at the end of a mashing step, before the mashed composition is conveyed to the next step of the brewhouse process, for example at the point before the mashed composition leaves a conversion vessel, e.g. mash tun. As used herein, the terms “mashing-in” or equivalently “mash-in” refer to the conditions at the start of a mashing step, for example as a composition for mashing enters a conversion vessel, e.g. mash tun. As used herein, the term “sugar spectrum” refers to the relative wt% amounts in a wort of sugars having different degrees of polymerisation. Sugars having a degree of polymerisation of 4 or higher are generally considered to be unfermentable, so should desirably be minimised. DETAILED DESCRIPTION The present invention provides a process for preparing a very high gravity (VHG) wort having a gravity of at least 18 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio of 2.4:1 or less and comprising weak wort; b) mashing the composition provided in step (a) to provide a mashed composition; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of at least 16 °P, a filter cake, and a weak wort; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of at least 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 23.5 °P. The VHG wort may preferably have a gravity of greater than 18 °P, more preferably greater than 19 °P, still more preferably greater than 20 °P, still more preferably greater than 21 °P, still more preferably greater than or equal to about 22 °P. The VHG wort may preferably have a gravity between 18 to 27 °P, more preferably between 18.5 to 26 °P, still more preferably between 19 to 24 °P, still more preferably between about 20 to about 22 °P. It is particularly preferred that the VHG wort has a gravity of greater than 18 °P and less than or equal to 22 °P. It has been found that the process of the present invention is able to produce VHG worts having such desirably high gravities. The process of the present invention reduces the amount of water and energy input required in the brewhouse, reducing economic and environmental costs. This is reflected in high gravities throughout the process. At the same time, it has been found that quality parameters, such as taste, RDF, and sugar spectrum, need not be negatively affected. Composition for mashing The process of the present invention comprises a step (a) of providing a composition for mashing. The composition has a watengrist ratio of 2.4:1 or less. In other words, in a mashing step, the water:grist ratio in the conversion vessel, e.g. mash tun, has this value. Preferably, the water: grist ratio is 2.3:1 or less, more preferably 2.2:1 or less, still more preferably 2.1:1 or less, still more preferably 2.0:0 or less, such as about 1.9:1 or less. Preferably the water: grist ratio is between 1.7:1 to 2.4:1, more preferably 1.8:1 to 2:25, still more preferably about 1.9:1 to about 2.2:1. A particularly preferred water: grist ratio is greater than or equal to 1.9:1 to less than 2.2:1. The composition comprises weak wort. It is preferred that the weak wort has a gravity of greater than 3 °P. Alternatively, the composition preferably comprises weak wort having a gravity of greater than 5 °P, more preferably greater than 7.5 °P, still more preferably greater than 10 °P. Preferably, the weak wort has a gravity of less than 23.5 °P, more preferably less than 22 °P, still more preferably less than 20 °P, still more preferably less than 15 °P, still more preferably less than 12.5 °P, still more preferably less than 10 °P, still more preferably less than 7.5 °P. Preferably, the weak wort has a gravity of between 3 to 23.5°P, more preferably 5 to 20 °P, still more preferably 7.5 to 15 °P, still more preferably 10 to 12.5 °P. Alternatively, the weak wort preferably has a gravity of between 3 to 15 °P, more preferably 3.5 to 12.5 °P, still more preferably 4 to 10.5 °P. Alternatively, the weak wort may preferably have a gravity of between 3 to 10 °P. Using both a low WTGR and weak wort in the mashing step has the advantage that a lower volume of water need be provided and then heated, reducing economic and environmental costs. It has been found that these effects can be realised without need for a reduction in quality parameters. Preferably, the process of the present invention is repeated a plurality of times. In other words, the process is preferably an iterative process comprising two or more iterations. Preferred numbers of iterations include, 2, 3, 4, and 5 iterations. Alternatively, the process may preferably be repeated as a continuous process. When the process is repeated, the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is preferably the weak wort provided in step (c) of a previous, preferably the previous, iteration of the process. In other words, the weak wort provided in step (c) may be recycled and used in step (a) of a subsequent, preferably the subsequent, iteration of the process. Recycling weak wort in this way has the advantage of ensuring that material is not wasted in one iteration of the process to the next. The mashing composition comprises grist and water. The water comprises weak wort as hereinbefore described. In such a case, the volume of weak wort is preferably greater than the volume of water. The volume ratio of water to weak wort is preferably 0:100 to 50:50, preferably 1:99 to 25:75, more preferably 2:98 to 20:80. Preferably, the water consists of weak wort. In other words, the volume ratio ofwater to weak wort is preferably 0:100. Preferably, weak wort is the only liquid present in the mashing composition. Using a greater volume of weak wort is advantageous as it may maximise the possibility for recycling the products of an iterative process and may reduce both the amount of water use and the amount of wasted material. However, the weak wort provided after sparging may be of a temperature greater than that suitable for mashing-in. Mixing the weak wort with water of ambient temperature may therefore provide for a better temperature of liquid for mashing-in, without need to wait for natural cooling. Preferred mashing-in temperatures are discussed below. Accordingly, the ratio of water to weak wort is preferably configured to provide a desired mashing-in temperature, while preferably maximising the relative proportion of weak wort. It may also or alternatively be preferred that a cooling apparatus, e.g. a heat exchanger, is employed to cool the weak wort to a desired mashing-in temperature. Mashing The process of the present invention includes a step of mashing the composition provided in step (a) to provide a mashed composition. Means of mashing will be known to the skilled person. Mashing may, for example, be conducted in a conversion vessel, such as a mash tun. It has been observed that a VHG brewhouse process may be associated with an increase in viscosity of the compositions of the process. This may, for example, contribute to a decrease in mixing efficiency in the mashing step. These effects may be mitigated by increasing agitation in the mashing step, ensuring no dry dumping occurs by reducing the flow rate of mashing in volume or filling speed of raw material, and lastly by employing specialist equipment. For example, a gravity premasher or a mechanical premasher may preferably be used in the mashing step. Mashing is generally conducted according to a certain so-called brewing diagram, which specifies a sequence of temperature increases and periods of rest at such temperatures. A purpose of the brewing diagram is to enable saccharification. The exact form of the brewing diagram will be dependent on the exact beverage being brewed, so its form is not intended to be particularly limited by the present invention. A preferred mashing-in temperature is between 50 and 70 °C, more preferably between 55 and 68 °C, still more preferably between 57 and 66 °C. Preferably, mashing-in temperatures are selected from about 66°C, about 63 °C, and about 57 °C. When the mashing-in temperature is about 66 °C, preferably any liquid in the mashing composition has a water to weak wort ratio of about 2:98. When the mashing-in temperature is about 63 °C, preferably any liquid in the mashing composition comprises has a water to weak wort ratio of about 8:92. When the mashing-in temperature is about 57 °C, preferably any liquid in the mashing composition comprises has a water to weak wort ratio of about 19:81. It is thought that high viscosities associated with a VHG brewhouse process may pose a risk of lower RDF. However, the present inventors understand that extending the rest periods for saccharification in the brewing diagram may contribute to a desirable RDF when using a VHG brewhouse process. For example, a brewing diagram may often include a rest at 60 to 70 °C, for example 61 to 67 °C, 62 to 66 °C, or 63 to 65 °C, i.e. about 63 °C. The duration of such a rest may preferably be, for example, about 5 minutes longer than normal, preferably from 5 to 20 minutes longer than normal, for example 5, 10, 15, or 20 minutes longer than normal. Preferably in the process of the present invention, mashing comprising a rest at 60 to 70 °C, preferably about 63 °C, such as between 62 to 66 °C, for greater than 30 minutes, preferably greater than 35 minutes, more preferably greater than 40 minutes. Filtering and sparging The process of the present invention comprises a step (c) of filtering and sparging the mashed composition provided in step (b). Means of filtering and sparging will be known to the skilled person. This step provides a pre-boil wort having a gravity of greater than 16 °P, a weak wort, and a filter cake. The pre-boil wort comprises first wort having a gravity of greater than 23.5 °P, e.g. greater than or equal to 24.5 °P. In other words, the step of filtering provides a first wort which, together with some of the filtrate produced in sparging, forms part of the pre-boil wort. The high gravity of the first wort reflects the high-gravity nature of the preceding brewhouse steps and has an advantage of reducing the energy input required in the boiling step. Preferably, the first wort has a gravity of greater than 24 °P, more preferably greater than 24.5 °P, still more preferably greater than 26 °P, still more preferably greater than 28 °P. Preferably, the first wort has a gravity of between 23.5 and 35 °P, more preferably between 24 and 32 °P, still more preferably between 24.5 and 30 °P. In sparging, a division is made between filtrate which is to be designated to form part of the pre-boil wort and filtrate which is to be designated weak wort. Pre-boil wort will be carried forward to boiling step (d). Weak wort is not carried forward to the boiling step and may instead be collected, for example in a weak wort tank, from whence it may be recycled, e.g. in a subsequent iteration of the process. The sooner the division between weak wort and pre-boil wort is made, the higher the gravity of the pre-boil wort and thus the higher the gravity of the ultimate VHG wort. Such an earlier division may also be reflected in the weak wort having a higher gravity. Accordingly, in the process of the present invention, the gravity of the pre-boil wort is greater than 17.5 °P, preferably greater than 18 °P, more preferably greater than 19 T, still more preferably greater than or equal to 20 °P. Preferably, the gravity of the pre-boil is between 17.5 to 23 °P, more preferably 18 to 22 °P, still more preferably 18.5 to 21 °P. Such a high gravity of the pre-boil wort may reflect an early division between pre-boil wort and weak wort. Providing a pre-boil wort with such a high gravity is beneficial as it reduces the energy input required in boiling. Ordinarily, this would come at the cost of lost material in the weak wort or filter cake. However, the preferred recycling of weak wort in a subsequent iteration of the process of the present invention may mitigate this cost. Preferred gravities of the weak wort are as discussed above. As previously discussed, a VHG brewhouse process may be associated with an increased viscosity which may lead to a decreased filterability in the mash filter. Such viscosity issues may preferably be mitigated by the addition of enzymes to the mashing composition, such as p-glucanases and / or xylanases. In other words, the composition for mashing preferably comprises p-glucanases and / or xylanases. Viscosity issues may also be ameliorated with the adjustment of the mashing parameters. For example, by increasing the mashing-out temperature, the mashed composition provided for filtering may be less viscous, leading to improved filterability. Accordingly, in the process of the present invention, step (b) preferably comprises mashing the composition provided in step (a) to provide a mashed composition, wherein mashing includes raising the temperature of the mashed composition to a mashing-off temperature of greater than 78 °C, more preferably greater than 79 °C, still more preferably about 80 °C. Preferably, the mashing-off temperature is in the range of greater than 78 °C and no greater than 80 °C. Preferably the mashing off temperature is not higher than 80 °C. A temperature greater than 80 °C may be associated with an over extraction of polyphenols, and damage to filter sheets and chambers, which may, for example, comprise polypropylene. Preferably, the temperature of the sparging water used for sparging is the same temperature as the mashing-off temperature, with preferred temperatures as hereinbefore described. Accordingly, preferably sparging is at a temperature of greater than 78 °C, more preferably greater than 79 °C, still more preferably about 80 °C. Preferably, sparging is at a temperature in the range of greater than 78 °C and no greater than 80 °C. Preferably sparging is at a temperature not higher than 80 °C. In other words, preferably sparging comprises washing the filter cake with a sparging liquid at a temperature as previously mentioned. Sparging liquid is the liquid used for sparging. Preferably, the sparging liquid used for sparging comprises acids such as phosphoric acid, sulphuric acid, and / or lactic acid, which may reduce the over-extraction of polyphenols. In other words, preferably sparging comprises adding an acid, preferably phosphoric acid or sulphuric acid to a sparging liquid and washing the filter cake with the composition so-obtained. As a result, the sparging liquid may preferably have a pH of less than 7, for example, 6, 5, 4, 3, 2, or 1 or any intermediate value. As previously mentioned, the process of the present invention may preferably be repeated a plurality of times and the weak wort comprised in the composition in step (a) in one iteration of the process is preferably the weak wort provided in step (c) of the previous iteration of the process. Weak wort may also be recycled at various other stages of the process. For example, weak wort may be used in a step (a’) as defined later, and / or weak wort may be used in a sparging step as sparging liquid. In other words, preferably step (c) comprises sparging with a sparging liquid comprising weak wort, preferred gravities for which are as hereinbefore described. Using weak wort in this way has an advantage of reducing water input in the brewhouse process. As weak wort will typically be of elevated temperature already, it also reduces the energy input required to heat the sparging liquid, which may ordinarily be done to improve sparging efficiency. Said weak wort is preferably weak wort obtained in step (c) of the previous iteration of the process in a case where the process is repeated a plurality of times. Recycling weak wort in this way has the advantage of ensuring that material is not wasted in one iteration of the process to the next. It is preferred that weak wort used for sparging has a relatively low gravity, which may improve sparging efficiency. It will be understood that, where the process is repeated a plurality of times, e.g. where the process is an iterative process, in the very first iteration weak wort may not be available for step (a). However, it may be possible to provide weak wort from a separate process in this scenario. In the very last iteration there may be no need to collect weak wort in step (c) Boiling The process of the present invention comprises a step (d) of boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of greater than 18 °P. Means of boiling will be known to the skilled person, which may be done in a wort kettle. The preceding steps provide a pre-boil wort with a high gravity, thus reducing the energy consumption required in the boiling step, which may for example be reflected in a reduction in steam evolution. Preferably, boiling is performed with an evaporation rate of 15 % or less, preferably less than 12 %, more preferably less than or equal to about 10 %. Preferably, the evaporation rate is about 2-12 %, more preferably 4-10 %, still more preferably 4-8 %, still more preferably 4-6 %. Evaporation rate is judged by reference to the volume of liquid provided for boiling. In certain embodiments, boiling may comprise heating the pre-boil wort to a temperature below its boiling point, preferably from 96 to 99°C, for example 96, 97, 98, or 99, while simultaneously sparging an inert gas, preferably nitrogen, through the wort. In these embodiments, it may be possible to achieve very low evaporation rates while still achieving the main goals of boiling, such as removing volatiles such as dimethyl sulfide (DMS). In these embodiments, the evaporation rate may be less than 6%, preferably less than or equal to 4%, for example 1, 2, 3, or 4%. Properties As described in the Examples, the process of the present invention can provide a VHG wort which also maintains desirable levels of certain quality parameters, such as taste, RDF, and sugar spectrum. Preferably, the VHG wort comprises fewer than 15% of sugars having a degree of polymerisation of 4 or more, more preferably less than 13%, still more preferably less than 12%, still more preferably less than or equal to 11%. Percentage values are here presented based on the total mass of sugar in the wort. Additional steps The process of the present invention may comprise one or more additional steps, in addition to those already described. The process may include an additional step (a’) of processing a composition comprising one or more grains in a cereal cooker to provide a processed grain solution. Step (a’) may preferably run in parallel to step (a) and optionally step (b). The processed grain solution may be combined with the mashed composition provided in step (b). The resulting combination may then be subject to further mashing, with preferred mashing conditions being as discussed above. In other words, the process may comprise: a’) processing a composition comprising one or more grains in a cereal cooker to provide a processed grain solution; a) providing a composition for mashing having a water:grist ratio of 2.4:1 or less and comprising weak wort; b) mashing the composition provided in step (a) to provide a mashed composition; b”) combining the processed grain solution provided in step (a’) with the mashed composition provided in step (b), and, optionally, mashing the resulting composition; c) filtering and sparging the composition provided in step (b”) to provide a pre-boil wort having a gravity of at least 16 °P, a filter cake, and a weak wort; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of at least 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 23.5 °P. Preferably, the WTGR in step (a’), i.e. in the cereal cooker, in other words in the composition provided for step (a’), is preferably less than 4.4:1, more preferably less than 4:1, still more preferably less than 3.5:1, still more preferably less than 3.2:1, still more preferably less than 3:1, still more preferably less than 2.8:1. Preferably the composition in step (a’) comprises weak wort, which may be recycled from a previous iteration of the process. Preferably, weak wort is the only liquid in the composition of step (a’). Preferred gravities for weak wort are as discussed above. When the processed grain solution provided in step (a’) is combined with the composition for mashing provided in step (a), the resulting composition preferably has a WTGR of less than 2.9, more preferably less than 2.75, still more preferably less than 2.55, still more preferably less than 2.5, still more preferably less than 2.45, still more preferably less than or equal to 2.4, still more preferably less than or equal to 2.3. For example, this may be the WTGR in step (b”), e.g. in a conversion vessel in which step (b”) may be performed. The present invention also provides a process comprising an additional step of diluting the VHG wort to provide a diluted VHG wort having a desired gravity for fermentation. A preferred gravity for fermentation may be less than or equal to 18 °P, preferably less than 18 °P, more preferably less than 17 °P, still more preferably less than or equal to about 16 °P, still more preferably about 16 °P. Dilution may be with water which may comprise or consist of weak wort. The present invention also provides a process comprising an additional step of fermenting the VHG wort or diluted VHG wort to provide a fermented VHG wort. Means of fermentation will be known to the skilled person. Fermentation may be performed on the VHG wort directly, for which techniques are increasingly being developed. Alternatively, fermentation may be performed on a diluted VHG, given that fermentation techniques at low gravity are more established. The present invention also provides a process comprising an additional step of processing the fermented VHG wort to provide a fermented beverage. Such processing means will be known to the skilled person. The fermented beverage is preferably a beer. Accordingly, the present invention provides a process comprising: i) preparing a VHG wort according to a process as hereinbefore described; ii) optionally, diluting said VHG wort to provide a diluted VHG wort; iii) optionally, fermenting said VHG wort or said diluted VHG wort to provide a fermented VHG wort; and iv) optionally, processing said fermented VHG wort to prepare an alcoholic beverage. The above process comprises either steps (i) and (ii); steps (i), (ii), and (iii); steps (i), (ii), (iii), and (iv); steps (i) and (iii); or steps (i), (iii), and (iv). Step (iv) must be in combination with step (iii). Products The present invention also relates to a VHG wort obtained or obtainable, preferably obtained, by a process as hereinbefore described. The present invention also relates to a fermented beverage, preferably a beer, obtained or obtainable, preferably obtained, by a process as hereinbefore described. Preferred Processes Some preferred processes of the present invention are given below. A process for preparing a very high gravity (VHG) wort having a gravity of greater than 18 °P, preferably greater than 19 °P, more preferably greater than 20 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio (WTGR) of 2.3:1 or less, preferably 2.2:1 or less, more preferably 2.1:1 or less, and comprising weak wort; b) mashing the composition provided in step (a) to provide a mashed composition; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of at greater than 18 °P, preferably greater than 19 °P, more preferably greater than or equal to 20 °P, a filter cake, and a weak wort; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of greater than 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 24 °P, preferably greater than 26 °P, more preferably greater than 28 °P; and wherein the process is preferably an iterative process comprising two or more iterations and the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process. A process for preparing a very high gravity (VHG) wort having a gravity a gravity between 18 to 27 °P, more preferably between 18.5 to 26 °P, still more preferably between 19 to 24 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio (WTGR) of 1.7:1 to 2.4:1, more preferably 1.8:1 to 2:25, still more preferably about 1.9:1 to about 2.2:1, and comprising weak wort; b) mashing the composition provided in step (a) to provide a mashed composition; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of between 17.5 to 23 °P, more preferably 18 to 22 °P, still more preferably 18.5 to 21 °P, a filter cake, and a weak wort; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity between 18 to 27 °P, wherein the pre-boil wort comprises first wort having a gravity between 23.5 and 30 °P, preferably between 24 and 29 °P, more preferably between 24.5 and 28 °P; and wherein the process is preferably an iterative process comprising two or more iterations and the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process. A process for preparing a very high gravity (VHG) wort having a gravity of greater than 18 °P, preferably greater than 19 °P, more preferably greater than 20 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio (WTGR) of 2.3:1 or less, preferably 2.2:1 or less, more preferably 2.1:1 or less, and comprising weak wort having a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P; b) mashing the composition provided in step (a) to provide a mashed composition; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of at greater than 18 °P, preferably greater than 19 °P, more preferably greater than or equal to 20 °P, a filter cake, and a weak wort having a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of greater than 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 24 °P, preferably greater than 26 °P, more preferably greater than 28 °P; and wherein the process is preferably an iterative process comprising two or more iterations and the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process. A process for preparing a very high gravity (VHG) wort having a gravity a gravity between 18 to 27 °P, more preferably between 18.5 to 26 °P, still more preferably between 19 to 24 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio (WTGR) of 1.7:1 to 2.4:1, more preferably 1.8:1 to 2:25, still more preferably about 1.9:1 to about 2.2:1, and comprising weak wort having a gravity between 3 to 15 °P, preferably between 3.5 to 12.5 °P, more preferably between 4 to 10.5 °P; b) mashing the composition provided in step (a) to provide a mashed composition; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of between 17.5 to 23 °P, more preferably 18 to 22 °P, still more preferably 18.5 to 21 °P, a filter cake, and a weak wort having a gravity between 3 to 15 °P, preferably between 3.5 to 12.5 °P, more preferably between 4 to 10.5 °P; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity between 18 to 27 °P, wherein the pre-boil wort comprises first wort having a gravity between 23.5 and 30 °P, preferably between 24 and 29 °P, more preferably between 24.5 and 28 °P; and wherein the process is preferably an iterative process comprising two or more iterations and the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process. A process for preparing a very high gravity (VHG) wort having a gravity of greater than 18 °P, preferably greater than 19 °P, more preferably greater than 20 °P, the process comprising: a) providing a composition for mashing having a watergrist ratio (WTGR) of 2.3:1 or less, preferably 2.2:1 or less, more preferably 2.1:1 or less, and comprising weak wort having a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P; b) mashing the composition provided in step (a) to provide a mashed composition, wherein mashing includes raising the temperature of the mashed composition to a mashing-off temperature of greater than 78 °C, more preferably greater than 79 °C, still more preferably about 80 °C; c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of at greater than 18 °P, preferably greater than 19 °P, more preferably greater than or equal to 20 °P, a filter cake, and a weak wort having a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of greater than 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 24 °P, preferably greater than 26 °P, more preferably greater than 28 °P; wherein sparging is at a temperature of greater than 78 °C, preferably greater than 79 °C, more preferably about 80 °C; and wherein the process is preferably an iterative process comprising two or more iterations and the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process. A process for preparing a very high gravity (VHG) wort having a gravity of greater than 18 °P, preferably greater than 19 °P, more preferably greater than 20 °P, the process comprising: a’) processing a composition comprising one or more grains in a cereal cooker to provide a processed grain solution; a) providing a composition for mashing having a watergrist ratio (WTGR) of 2.3:1 or less, preferably 2.2:1 or less, more preferably 2.1:1 or less, and comprising weak wort having a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P; b) mashing the composition provided in step (a) to provide a mashed composition; b”) combining the processed grain solution provided in step (a’) with the mashed composition provided in step (b), wherein the resulting composition preferably has a WTGR of less than 2.9, more preferably less than 2.75, still more preferably less than 2.55, still more preferably less than 2.5, still more preferably less than 2.45, still more preferably less than or equal to 2.4, still more preferably less than or equal to 2.3, and, optionally, mashing the resulting composition; c) filtering and sparging the composition provided in step (b”) to provide a pre-boil wort having a gravity of at greater than 18 °P, preferably greater than 19 °P, more preferably greater than or equal to 20 °P, a filter cake, and a weak wort having a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P; and d) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of greater than 18 °P, wherein the pre-boil wort comprises first wort having a gravity of greater than 24 °P, preferably greater than 26 °P, more preferably greater than 28 °P; wherein sparging is at a temperature of greater than 78 °C, preferably greater than 79 °C, more preferably about 80 °C; and wherein the process is preferably an iterative process comprising two or more iterations and the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process. A process comprising: i) preparing a VHG wort according to a process as hereinbefore described; ii) diluting said VHG wort to provide a diluted VHG wort having a gravity of less than or equal to 18 °P, preferably less than 18 °P, more preferably less than 17 °P, still more preferably less than or equal to about 16 °P, still more preferably about 16 °P; iii) fermenting said diluted VHG wort to provide a fermented VHG wort; and iv) processing said fermented VHG wort to prepare an alcoholic beverage, preferably a beer. ILLUSTRATIVE EMBODIMENT The invention will now be described with reference to the following illustrative and nonlimiting example embodiment. A preferred process of the present invention is an iterative process. In a first iteration of the process, a weak wort may be collected following the filtration and sparging of a mashed composition. Said weak wort may be collected in a weak wort tank. Said weak wort may then be recycled to a conversion vessel, such as a mash tun, for step (a) of providing a composition for mashing. The composition for mashing has a WTGR of 2.4:1 or less. In step (b), the composition is mashed using methods known in the art, which may be according to a particular brewing diagram. Saccharification rest steps may be longer, for example about 5 minutes longer, than would normally be performed by the skilled person, in order to mitigate for an increase in viscosity which may be associated with the high gravity conditions. The mash-out temperature may also be higher than normal, for example about 80 °C, in response to the increased viscosity. The mashed composition is carried forward to step (c). Before step (c), a processed grain solution, obtained in an optional step (a’) of processing a composition comprising one or more grains in a cereal cooker to provide a processed grain solution, may optionally be combined in a step (b”) with the mashed composition obtained in step (b). The resulting composition may preferably have a WTGR of less than 2.9. The resulting composition may optionally be subject to further mashing. When this optional step (b”) is included, the resulting composition is then carried forward to step (c). In step (c), the mashed composition is subject to filtering. In addition to a filter cake, this step provides a first wort having a gravity of at least 23.5 °P. The first wort forms part of a pre-boil wort. The filter cake is then sparged with sparging liquid, with some of the filtrate being added to the first wort to form a pre-boil wort having a gravity of at least 16 °P. The remainder of the filtrate is designated as weak wort and may be diverted to a weak wort container. The point of division between filtrate to be included in the pre-boil wort and that to be designated as weak wort must be made to reflect the required gravity of the pre-boil wort. The sparging liquid may comprise or consist of weak wort. The weak wort may be recycled to steps of a next iteration of the process, for example in the mashing step (a), cereal cooker processing step (a’), and / or sparging step (c). Weaker wort having a relatively higher gravity may be better suited to the mashing and cereal cooker steps, while weak wort having a relatively lower gravity may be better suited to the sparging step. The pre-boil wort is then boiled to provide a VHG wort having a gravity of at least 18 °P. The VHG wort may then be diluted, preferably to about 16 °P, to provide a gravity which may be more suitable for fermentation. A fermentation step may then occur, and the fermented VHG wort may then be processed into a fermented beverage. By reducing the amount of water provided and thus heated, the process has the advantage of reducing environmental and economic costs normally associated with the brewhouse. At the same time, it does not compromise key quality parameters. EXAMPLES Preparation of VHG Wort The purpose of each of Examples 1 to 4 was to prepare a VHG wort which could then be diluted for fermentation. Each Example was prepared by processing a composition comprising one or more grains in a cereal cooker to provide a processed grain solution to be later combined; providing a composition for mashing having a certain WTGR; mashing the composition according to a particular brewing diagram in a conversion vessel; filtering the mashed composition to provide a first wort to form part of a pre-boil wort and a filter cake; and sparging the filter cake. During sparging, a division was made between filtrate to form part of the preboil wort and filtrate to be designated weak wort and collected in a weak wort tank. In Examples 1 to 4, all weak wort collected in a first iteration was returned to the mash tun for a second iteration. The values below are for this second iteration. Watergrist ratios (WTGR) in the mashing step conversion vessel are shown in Table 1. As can be seen, the Examples of the present application used a low WTGR in the mashing step. Example 1 2 3 4 WTGR in mashing step 2.1 2.1 2.3 2.3 Table 1: WTGR in mashing step Total sparging volumes and the volume of collected weak wort are shown in Table 2. The Examples of the present application make a relatively early division between preboil wort and weak wort, as reflected by the high weak wort volume relative to the total sparge volume. Example 1 2 3 4 Total sparge volume input (hL) 240 250 250 250 Collected weak wort volume (hL) 130 130 130 130 Table 2: sparge and collected weak wort volumes Wort gravities obtained at different stages of each process are shown in Table 3. For Examples 3 and 4, two trials were run. All values are presented in °P. First wort refers to the filtered wort before sparging. Pre-boil wort comprises first wort and the product of sparging before a switch to the weak wort tank was made. VHG wort refers to wort following boiling. Diluted VHG wort refers to wort diluted for fermentation. Example First wort Pre-boil wort VHG wort Diluted VHG wort 1 26,9 20,88 24,3 16 2 28,1 20,9 22,7 16 3 (trial 1) 27,7 19,3 21,8 16 3 (trial 2) 25,4 18 19,9 16 4 (trial 1) 26,9 18,7 20,7 16 4 (trial 2) 27,2 18,6 20,4 16 Table 3: wort gravities As can be seen, the Examples of the present invention were able to yield a preboil wort having a high gravity. This reduces the amount of energy needed in the boiling step. The Examples also yielded VHG wort with high gravities, indicating that the process of the present invention is suitable for the preparation of VHG worts. Preparation and quality analysis of VHG wort The purpose of Examples 5, 6, and 7 was to prepare VHG worts which could then be analysed for various quality parameters. The worts were prepared according to the same general procedure as described above for Examples 1 to 4, though for a different recipe, where results for a second iteration using recycling of weak wort are presented. Examples 5 and 6 included a saccharification rest period which was extended by approximately 5 minutes relative to Example 7. The approximate water volumes used in the various steps of the process are summarised in Figure 1. The Examples used a WTGR in the mashing step of between 1.9 to 2.2, with Example 7 using a higher WTGR than Examples 5 and 6. Figure 1: volumes used at different brewhouse process steps. Light grey / left-most in triplet series = Example 7, dark grey / centre of triplet series = Example 5, white / rightmost in triplet series = Example 6 Approximate wort gravities obtained at different stages of the process are summarised in Table 4 below. Example First wort Preboil wort VHG wort Diluted wort 5 27.5 19 20 18 6 Not recorded Not recorded 22 18 7 24.5 17.2 18 18 Table 4: wort gravities Accordingly, the Examples of the present invention were able to yield a preboil wort having a high gravity. This reduces the amount of energy needed in the boiling step. The Examples also yielded VHG wort with high gravities, indicating that the process of the present invention is suitable for the preparation of VHG worts. Examples 5 and 7 were carried forward for quality testing. Table 5 shows the sugar spectrum analysis for industrial-scale preparations of Examples 5 and 7. As can be seen, there was no significant difference in the sugar spectrums, save for differences considered as rounding errors. This shows that decreasing a WTGR and increasing weak wort collection and recycling does not have a detrimental impact on sugar spectrum. The results for both examples were in line with the relevant commercial specification ranges for the recipe under consideration. Sugar degree of polymerisation % of sugar in sample Example 5 Example 7 DP = 1 14 13 DP = 2 57 57 DP = 3 18 18 DP >3 (non-fermentable) 11 11 Table 5: sugar spectrum Comparative tests for RDF, wort and beer colour, wort DMS, FAN and foam stability, and taste were also conducted for Examples 5 and 7. The results and testing methods are summarised in Table 6. The results for both examples for each parameter were in line with the relevant commercial specification ranges for the recipe under consideration. It was also observed that there was no significant difference between the two Examples, again showing that decreasing a WTGR and increasing weak wort collection and recycling does not have a detrimental impact on quality parameters. Parameter Test Method Reference Example 5 Example 7 RDF EBC 9.5 - Real Degree of Fermentation of Beer In spec. In spec. Wort and beer colour EBC 8.5 - Colour of Wort: Spectrophotometric Method EBC 9.6 - Colour of Beer: Spectrophotometric Method In spec. In spec. Wort DMS EBC 9.39 - Dimethyl Sulphide and Other Lower Boiling Point Volatile Compounds in Beer by Gas Chromatography In spec. In spec. FAN and foam stability EBC 9.10.1 - Free Amino Nitrogen in Beer by Spectrophotometry (IM) In spec. In spec. Foam stability Using a NIBEM foam stability tester In spec. In spec. Taste Qualitative points-based survey of taste panel, based on a predetermined set of taste criteria In spec. In spec. Table 6: quality parameters Accordingly, the Examples of the present invention achieve very high gravity worts without compromising quality parameters such as sugar spectrum, RDF, colour, DMS, and taste. 10 Conclusion As demonstrated in Examples 1 to 7, the process of the present invention is able to yield VHG worts having desirably high gravities at various stages of the process. At the same time, the VHG worts are able to maintain quality parameters within a desired specification. 15 Accordingly, the process of the present invention is considered to be a highly effective option for reducing the economic and environmental costs associated with the brewhouse, while still maintaining the quality of the final product.

Claims

1. A process for preparing a very high gravity (VHG) wort having a gravity of at least 18 °P, the process comprising:a) providing a composition for mashing having a watergrist ratio (WTGR) of 2.4:1 or less and comprising weak wort;b) mashing the composition provided in step (a) to provide a mashed composition;c) filtering and sparging the mashed composition provided in step (b) to provide a pre-boil wort having a gravity of at least 16 °P, a filter cake, and a weak wort; andd) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of at least 18 °P,wherein the pre-boil wort comprises first wort having a gravity of greater than 23.5 °P.

2. A process according to claim 1, wherein the VHG wort has a gravity of greater than 18 °P, preferably greater than 19 °P, more preferably greater than 20 °P, still more preferably greater than 21 °P, yet more preferably greater than or equal to about 22 °P.

3. A process according to claim 1 and claim 2, wherein the VHG wort has a gravity of between 18 to 27 °P, preferably between 18.5 to 26 °P, more preferably between 19 to 24 °P, still more preferably between about 20 to about 22 °P.

4. A process according to any preceding claim, wherein the composition for mashing has a WTGR of 2.3:1 or less, preferably 2.2:1 or less, more preferably 2.1:1 or less, still more preferably 2.0:0 or less, such as about 1.9:1 or less.

5. A process according to any preceding claim, wherein the weak wort has a gravity greater than 3 °P, preferably greater than 5 °P, more preferably greater than 7.5 °P, still more preferably greater than 10 °P6. A process according to any preceding claim, wherein the weak wort has a gravity of between 3 to 15 °P, preferably between 3.5 to 12.5 °P, more preferably between 4 to 10.5 °P.

7. A process according to any preceding claim, wherein the process is an iterative process comprising two or more iterations.

8. A process according to claim 7, wherein the weak wort comprised in the composition for mashing in step (a) in one iteration of the process is the weak wort provided in step (c) of the previous iteration of the process.

9. A process according to any preceding claim, wherein in the composition for mashing the volume ratio of water to weak wort is 0:100 to 50:50, preferably 1:99 to 25:75, more preferably 2:98 to 20:80.

10. A process according to any preceding claim, wherein the mashing step comprises a rest at 60 to 70 °C, preferably about 63 °C, such as between 62 to 66 °C, for greater than 30 minutes, preferably greater than 35 minutes, more preferably greater than 40 minutes.

11. A process according to any preceding claim, wherein step (b) comprises mashing the composition provided in step (a) to provide a mashed composition, wherein mashing includes raising the temperature of the mashed composition to a mashing-off temperature of greater than 78 °C, more preferably greater than 79 °C, still more preferably about 80 °C.

12. A process according to any preceding claim, wherein the gravity of the pre-boil wort is greater than 17.5 °P, preferably greater than 18 °P, more preferably greater than 19 °P, still more preferably greater than or equal to 20 °P.

13. A process according to any preceding claim, wherein the gravity of the pre-boil wort is between 17.5 to 23 °P, preferably between 18 to 22 °P, more preferably between 18.5 to 21 °P.

14. A process according to any preceding claim, wherein the first wort has a gravity of greater than 24 °P, preferably greater than 26 °P, more preferably greater than 28 °P.

15. A process according to any preceding claim, wherein the first wort has a gravity of between 23.5 and 30 °P, preferably between 24 and 29 °P, more preferably between 24.5 and 28 °P.

16. A process according to any preceding claim, wherein the composition for mashing comprises p-glucanases and / or xylanases.

17. A process according to any preceding claim, wherein sparging is at a temperature of greater than 78 °C, preferably greater than 79 °C, more preferably about 80 °C.

18. A process according to any preceding claim, wherein step (c) comprises sparging with a sparging liquid comprising or consisting of weak wort.

19. A process according to any preceding claim, wherein the VHG wort comprises fewer than 15 % of sugars having a degree of polymerisation of 4 or more, preferably less than 13 %, more preferably less than 12%, still more preferably less than or equal to 11 %, wherein percentage values are based on the total mass of sugar in the VHG wort.

20. A process according to any preceding claim, comprising:a’) processing a composition comprising one or more grains in a cereal cooker to provide a processed grain solution;a) providing a composition for mashing having a watergrist ratio of 2.4:1 or less and comprising weak wort;b) mashing the composition provided in step (a) to provide a mashed composition;b”) combining the processed grain solution provided in step (a’) with the mashed composition provided in step (b), and, optionally, mashing the resulting composition;c) filtering and sparging the composition provided in step (b”) to provide a pre-boil wort having a gravity of at least 16 °P, a filter cake, and a weak wort; andd) boiling the pre-boil wort provided in step (c) to provide a VHG wort having a gravity of at least 18 °P,wherein the pre-boil wort comprises first wort having a gravity of greater than 23.

521. A process according to any preceding claim 20, wherein the WTGR in step (a’) is less than 4.4:1, preferably less than 4:1, more preferably less than 3.5:1, still more preferably less than 3.2:1.

22. A process according to claim 20 or 21, wherein the composition in step (a’) comprises weak wort.

23. A process comprising:i) preparing a VHG wort according to a process as defined in any preceding claim;ii) optionally, diluting said VHG wort to provide a diluted VHG wort;iii) optionally, fermenting said VHG wort or said diluted VHG wort to provide a fermented VHG wort; andiv) optionally, processing said fermented VHG wort to prepare an alcoholic beverage, wherein the process comprises steps (i) and (ii); steps (i), (ii), and (iii); steps (i), (ii), (iii), and (iv); steps (i) and (iii); or steps (i), (iii), and (iv).

24. A VHG wort obtained or obtainable, preferably obtained, by a process as defined in any one of claims 1 to 22.

25. A fermented beverage, preferably a beer, obtained or obtainable, preferably obtained, by a process as defined in claim 23, wherein said process includes step (iv).

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