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20without exposing it to unwanted contamination.62 Figure 4 shows the wort going from keg kettle, through the garden hose wort chiller, and into the five-gallon glass carboy where the yeast will be added and controlled fermentation will take place. Generic brewer%u2019s lager and ale yeast wereall that was available in the late 1970s and early 1980s, though now there are hundreds of yeast strains available to homebrewers and professional brewers alike. The brewer%u2019s yeast strains are separated into seven broad categories based on desired fermenting outcomes, and are used alongside wild, once-undesirable strains that have now been %u201ctamed.%u201d63 Since cascade hop pellets were ubiquitous in early craft beers from Anchor, New Albion, Sierra Nevada, and others, they became the flavor and aroma of %u201cgood beer.%u201d Homebrewers sought out this specific hop variety to recreate the new craft beer styles.64Figure 6 shows yeast happily fermenting (as brewers say), converting the sugars in the wort and producing flavor compounds, carbon dioxide, and ethanol (base alcohol). Owens used two five-gallon glass carboys with a water-filled airlock on the left and a blow-off tube on the right. These devices prevent airborne bacteria from interrupting the yeast at work while allowing carbon dioxide to escape, preventing a literal blow-up of foamy, yeasty, sticky liquid. The converted mini-fridge allows for temperature control. Glass carboys allow the brewer to watch yeast activity. The timing of yeast completing their work depends on the type and health of the yeast, amount of sugar in the wort, ambient temperature, and other factors. Owens suggests fermenting at 70 degrees or room temperature using ale yeast (ale yeast happily ferments at warmer temperatures while lager yeast want cooler temperatures). Once yeast activity stops, the brewer transfers the beer away from the trub%u2014the yeast, malt proteins, and hop material that settles to the bottom of the fermenter. The brewer may transfer the beer to a keg or bottles, or may transfer to a secondary fermenter for lagering%u2014the German term for %u201cstoring.%u201d Beer is