Pollution Sources and Countermeasures in Beer Brewing Process During beer brewing, hygiene plays a key role in producing high-quality beer. Microorganisms found in brewery environments and controlling microbial contamination are critical to preventing microbial spoilage of beer. Many common odors stem from wild yeast or bacterial contamination that grows in little nooks and crannies. So we have to take beer hygiene seriously, many things can be a source of contamination, so sanitize after the brewing process, like fermenters and hoses. Next, our engineers will take you to understand the source of pollution.