Sweet wort

The basic raw materials for the production of beer are sweet worts formed by en2ymatic hydrolysis of cereal starches. The principal cereal is barley which, after malting, is also the source of en2ymes that hydroly2e starches, glucans, and proteins. In some countries, eg, Germany, the mash biH consists... 

The new edition appears as two volumes because a single one would be inconveniently bulky. The first volume outlines the entire process and leads from barley, malting and water to the production of sweet wort. In the second volume there are chapters on hops and hop products, production of hopped wort, fermentation, yeast biology and all aspects of beer qualities and treatment. 

If mash temperatures in the brewhouse fall or sweet wort is held at temperatures below 60 C (140°F), there is a danger that thermophilic bacteria will... 

Wort bacteria not belonging to the family Enterobacteriaceae may be present in small numbers, such as species of Achromobacter, Acinetobacter and Pseudomonas. They are more sensitive to pH and ethanol than the majority of the brewery enterobacterial strains. Still other bacteria may be present in sweet wort, sometimes in appreciable numbers, arising from the microbial flora of raw materials, particularly malt. Most of these bacteria fail to grow in the wort. 

Bacterial spoilage at various stages in the brewing process The spoilage caused by bacteria at the various stages of the brewing process are outlined in Table 21.2. The infection of sweet-wort by thermophilic lactic acid bacteria has already been mentioned. Because these bacteria are sensitive to isohumulones, they do not survive in hopped wort. 

I Mashing and sweet>wort Thermophilic lactic acid bacteriaf... 

Apart from spoilage incidents of beer products, certain thermophilic lactobacilU, including Lactobacillus delbrueckii, have been noted as contaminants of sweet wort. They are killed by the boiling process, but if the wort is kept sweet for an extended period, even stored hot (less than 60 °C), thermophilic lactobacilli spoil sweet wort by producing lactic acid (Priest, 2(X)6). 

Compare enzyme hydrolyses for production of glucose syrups and sweet worts for grain bioethanol production. 

During mashing with rice or maize adjuncts, about 80% of the grits are solubilized or extracted and become part of the sweet wort. The soluble solids are mainly dex-trins, maltose, maltotriose, glucose, and FAN. If starch is used, the extraction rates are usually 100 or more because the hydrolyzed starch gains water after conversion. 

Chicha could be obtained from two processes one where saliva is used as a source of starch-hydrolyzing enzymes, and the second where maize malt supplies the starch-degrading enzymes. Chicha could be also produced by combining salivation and malt (Figure 16.9). After enzyme conversion, the mash prodnces a sweet wort that is naturally fermented into the alcoholic beverage. 

Lautering The act of separating sweet wort from spent grains after mashing. 

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