The Role of Starch in Brewing Beer

Brewing beer is a complex process that requires a variety of ingredients, including starch. Starch is a polysaccharide, which means it is composed of carbon, oxygen, and hydrogen. It is broken down into sugars during the brewing process to create wort, which is then fermented into beer. Malted barley is the most common source of starch used in brewing, but other grains such as wheat and rice can also be used.

In the maceration phase, starch is converted into fermentable sugars by specific enzymes (amylase) present in malt. The brewer can use iodine (or iodophor) to check a sample of the wort and see if the starches have completely converted to sugars. As you may remember from high school chemistry, iodine causes starch to turn black. Maceration enzymes must convert all starches, which does not produce any color change when a couple drops of iodine are added to a sample of the wort.

The wort sample must not contain grain particles. Musts with a high content of dextrins will produce a strong reddish color when iodine is added. Starch granules have an internal structure, with tightly packed regions of amylose molecules and regions of amylopectin less dense and more amorphous. Both proteins and lipids are associated with starch granules and their presence can inhibit the action of amylase enzymes. By altering the temperature, pH and time of the mash or performing a staggered puree, a brewer can potentially alter the yield of his extract, the fermentability of the must and influence other variables. For the production of high-quality beers, cereals and pseudo-cereals (buckwheat, quinoa and amaranth), as well as tubers (sweet potatoes) are being promoted for use as starch additives in brewing beer.

The Food and Agriculture Organization of the United Nations (FAO) reports that there are 11 starch additives among cereals and pseudocreals that have a wide application in brewing. Although it dealt with all enzymes relevant to brewing, not just starch-degrading enzymes, it can be considered that these starch articles cover much of the same or similar terrain, but from the perspective of the substrate, not the enzymes. The vast majority of beers on the market today contain a wide variety of starch additives, some of which can reduce production costs or improve several beer quality attributes, such as color or taste, although not all starch additives have the right attributes to be used in brewing beer. It is useful to understand the molecular structure of starch and the degradation process when choosing a maceration program and when monitoring extraction. In conclusion, starch plays an important role in brewing beer. Starch granules have an internal structure with tightly packed regions of amylose molecules and regions of amylopectin less dense and more amorphous.

By altering certain variables such as temperature, pH and time of mash or performing a staggered puree, brewers can potentially alter their extract yield and fermentability.