Chapter 21

Beer Spoilage Organisms

Major Beer Spoilers

There are two major groups of microorganisms responsible for contaminating wort and beer: bacteria and wild yeast and to a lesser extent molds. From a microbiological standpoint, the brewing process can be broken down into various stages from malting followed by those that include wort production, fermentation, and subsequent beer processing. Microorganism contamination can occur during anyone of these stages. A summary of such microorganisms and the stages of the brewing process at which they are found are outlined in Figure 21.1 and will be discussed in more detail further below. The spoilage character of a particular organism will depend on the stage at which it is found in the brewing process.

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