Even for an old industry like beer brewing new industrial processes benefit from using enzymes developed from microbial sources. In the last years quality issues like flavour control, beer stability and general cost savings in the industry go hand in hand with efficient solutions of environmental problems. Future aspects focus on a wider application of enzymes to brew with high amounts of inexpensive raw materials like barley. Alternative beer processes for production of wort and beer with higher productivity and reduced amounts of waste and by-products are under development
In former days, production of malt was an integrated part of every brewery, but today most malt is produced outside the brewery in large malt factories, and malt has become a purchased raw material, like other raw materials. This means that the breweries today are more flexible in the use raw materials, and for that matter for the source of enzymes.
The malt enzymes do have some limitations. 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 easier, faster and more consistent. It gives the brew masters extra flexibility in the choice of raw materials due to less dependence on malt enzymes, as well as providing 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 possible with commercial enzymes. The increasing concern on resources and CO2- emission has also put the use of commercial 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.
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 best at 52 ºC, the β-amylase best at 63 ºC and the α-amylase at 72°C. The last step in the mashing is inactivation of the enzymes at 78 ºC.