- Jul 3, 2019
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Beer and wine play an indispensable role in our social life for thousands of years. Yeast fermentation of sugars is used to produce both the drinks. Wine is a grape-based product, and beer is traditionally based on barley. The matured grapes already contain the sugar which is needed for the product fermentation, whereas, barley contains starch which needs to be broken down to fermentable sugars prior the yeast can make alcohol. Therefore, traditional brewing includes an extra step compared with winemaking, namely malting in which enzyme needed for the degradation of starch into fermentable sugar are produced.
Even for a traditional industry like beer brewing, newly developed industrial processes benefit from using enzymes derived from microbial sources. In the past years, quality issues like flavour control, beer stability and overall cost reductions in the industry go along with efficient solutions of environmental problems. Future aspects focus on a broader application of enzymes to brew with high amounts of inexpensive raw materials like barley. Alternative beer processes for the production of wort and beer with higher productivity and reduced costs of waste and by-products are under development.
Protease used for malt improvement and improved at yeast growth.
Xylanase improves extraction and beer filtration.
Fungal Alpha Amylase
Increase the percentage of fermentable sugar in light beer.
The malt enzymes also have some limitations. For instance, they can only work at certain temperatures, pH values, etc., and the activities might be too low to do a proper job in proper time. In contrast, commercial exogenous enzymes can be designed to work at preferred temperatures and pH values, to have more enzymatic power, or to express wanted enzyme activities that are not present in malt. Addition of exogenous enzymes at various steps during the brewing process can, therefore, make brewing more accessible, faster and improve consistency. It gives the brewmasters more comprehensive flexibility while choosing raw materials due to less dependency on malt enzymes.
Furthermore, providing an opportunity to create new products, which is not possible to make with malt enzymes alone. Also, the possibility to improve beer quality by avoiding off-flavours is viable with commercial enzymes. The increasing concern on resources and CO2- emission has also put the use of industrial enzymes within the brewing industry in focus. By the use of exogenous enzymes more can be extracted from the raw materials, more local raw materials can be used, and more unmalted grains can be used, saving significant amounts of energy and transport.
The brewing process
Traditionally, beer is produced by mixing crushed barley malt and hot water in a mash copper to perform the mashing. Besides malt, other starchy cereals such as maize, sorghum, rice and barley, or pure starch itself, can be added to the mash. These are known as adjuncts.
The standard mashing for pilsner type beer consists of several temperature steps, each favouring different malt enzyme activities. The lowest temperature (45 ºC) is the optimal temperature for cell wall degrading enzymes, β-glucanases. The proteases work more efficiently at 52 ºC, the β-amylase at 63 ºC and the α-amylase at 72°C. The last step in the mashing is the inactivation of the enzymes at 78 ºC.
Enzymes at work
Many breweries have run programs within the last two years to increase efficiency and optimize raw material usage. Many of them have focused on commercial enzymes to shorten the production time, increase capacity, and to allow the use of a raw material alternative to malt. Three outstanding examples are mentioned:
Exchanging part of the malt with barley has been quite popular because using barley along with commercial enzymes will give the same quality beer as with malt.
Introducing a higher content of starch hydrolyzing enzymes offer the possibilities of producing “light beer” also called “low-calorie beer”.
An enzyme solution for diacetyl control after fermentation improves vessel utilization, save energy and ensures a high beer quality after a reduced maturation time.