One factor that can impact the quality of your beer is fermentation loss. This occurs when some of the beer is absorbed by the yeast during fermentation. Let’s discuss the factors that can reduce beer fermentation.
Using a low-quality brewer’s yeast is one of the biggest mistakes you can make during fermentation. This not only leads to increased beer loss but can also result in off-flavors and affect the appearance of the beer. For optimal results, use a high-quality starter culture or fresh dry yeast that has been packaged within the last six months. If you’re using liquid yeast, ensure that it has been stored correctly, between 59°F and 72°F, with sufficient oxygen to prevent stress before pitching it into the fermenter. It’s important to note that different yeast strains have different optimal temperatures for activity. If you’re uncertain about which strain is best suited for your desired style or process temperature range, consult an experienced professional before making any decisions.
Pitching an adequate amount of yeast is crucial to ensure complete and clean fermentation. If you pitch too little yeast, fermentation may stall or stop before reaching the desired terminal gravity (SG). In such cases, you’ll have a thick layer of yeast at the bottom of the fermenter, which can contribute to off-flavors in the beer.
If you notice an active fermentation that’s progressing slower than expected or if there are signs of contamination, such as bubbles in the airlock or mold growth on the wort’s surface, it might be necessary to discard some unfermented wort and pitch fresh yeast. If you don’t have access to another yeast culture, you can use canned liquid malt extract that has been boiled to kill any bacteria. Measure out the extract into a sanitized flask. Avoid using boiling water from a kettle as an alternative, as it could also kill any desirable yeasts present on your equipment.