Beta-amylase is capable of breaking down starches into soluble sugars. After the alpha-amylase added, it create smaller soluble molecules but beta-amylase produce most of the fermentable sugars by breaking down starch to create maltose, glucose and maltose. These enzymes help create lighter bodies and more alcohol and are most active from 131°F-149°F. As the temperature approaches 149°F, these enzymes are operating extremely fast, but are also being denatured quickly.
Alpha and beta-amylase act together to degrade starches to produce a range of soluble sugars in the wort. Below a certain temperature (149°F), alpha-amylase activity is low and so the large starch molecules remain insoluble because the enzyme is unable to break them up. Same goes for above a certain temperature (150° F), beta-amylase activity is hindered, limiting the amount of fermentable sugars for the wort.
beta glucanase is an enzyme that hydrolyzes β-glucans. The most important β-glucanases for brewing are those that break down the β-glucans located in the cell walls of the barley endosperm. High levels of β-glucans in brewing raw materials are to be avoided as they can cause problems, particularly in wort production and beer filtration. β-Glucanases are important in that they are needed to break down the complex β-glucan molecules to smaller units. There is a wide range of such enzymes, differing in the specific bonds that are broken.
Protease & peptidase
Two groups of proteolytic enzymes are important in the brewing process, proteinase (protease) and peptidase.Proteinase breaks down the very large protein molecules into smaller amino acid chains, which enhances the head retention of beer and reduces haze. The other enzyme is peptidase. It breaks down the smaller amino acid chains released by proteinase, but only works from the ends, releasing nutrients used by the yeast.Proteins are important to us because after they are broken down by proteolytic enzymes, the resulting amino acids and other products are used nutrients by the yeast. Some protein remains in the finished beer giving it richness and mouthfeel. The proteins are also responsible for the beer’s head It is the nitrogen in proteins that combine with carbohydrates during kilning to produce many of the flavors we enjoy.
Dextrinase, are most active in this regime and break up a small percentage of dextrins at this early stage of the mash. The vast majority of debranching occurs during malting as a part of the modification process. Only a small percentage of the debranching enzymes survive the drying and kilning processes after malting, so not much more debranching can be expected. With all of that being said, the use of a 20 minute rest at temperatures near 104°F (40°C) has been shown to be beneficial to improving the yield from all enzymatic malts.
Lipase is produced during germination of barley. The malt lipase thus obtained can hydrolyse most trigiycerides into glycerol and free fatty acids. Consequently, barley grains contain higher amounts of lipids than malt grains. These lipids are able to build inclusion complexes with starch which makes starch degradation more difficult during mashing when barley is used as crude adjunct. Moreover lipids in the mash create an emulsion like medium leading to low filtrate rates. After wort filtration these lipids are found mainly in the spent grains causing rancidity, off-flavours, and others, which render cattlefeed application less acceptable. A minor amount (5-1 0%) is still found in the filtered wort with bad consequences on organoleptic properties of the final beer: no foam stability, staling, hazing
Beta-glycosidase enzymes can be added artificially, however there has been much interest in the natural capability of microorganisms to produce beta-glucosidases, particularly 1,4-β-glucosidase. Microorganisms that can break down glycosides by using beta-glucosidases can then access the resulting sugars for fermentation. There are two major categories of glucosidase activity: endogenous and exogenous. Endogenous enzymatic activity takes place inside of the cell, and exogenous enzymatic activity takes place outside of the cell. Bacteria and fungi that show endogenous glucosidase activity have been shown not to be effective in alcoholic fermentation due to not tolerating low pH (optimum pH of 5), glucose, and/or ethanol. Generally, the flavorless glycosides remain unaffected by yeast fermentation, leaving them unused as a potential source for flavor and aroma.