Sascha Wunderlich

1 – Overview of Manufacturing Beer: Ingredients, Processes, and Quality Criteria

Brewers worldwide produce beer at an advanced technological level while keeping in mind the importance of tradition. The basic ingredients are water, malted barley, hops, and yeast, as it is fixed in Germany by the legislation governing commercial brewing, the Reinheitsgebot (Purity Law) ( BGB1, 1993). Brewing technologies worldwide are based on this recipe, although brewers in other countries have more flexibility, for example in selection of starch supply. Nevertheless, barley is commonly used as the source of starch but it has to be malted to dissolve starch in the grains prior to brewing. Malting steps are steeping, germination, and kilning. Enzymes digest grain contents during these processes and prepare starch for further processes. Heating during kilning produces coloring and flavoring substances. Further enzymes convert the starch of milled malt to fermentable sugars during mashing. This procedure results in wort that is boiled. Hops are added in this stage of boiling. Yeast converts sugars to alcohol during fermentation of cooled wort. After maturation and storage, beer is filtered and stabilized to inhibit quality deficiencies. These may be turbidity, decrease of flavor stability, or decrease of foam stability. Each production step influences decisively the resulting beer. So, an enormous variety of beers is possible that are all tasty, thirst-quenching and healthy.