Use the freshest yeast possible.
- Yeast is sensitive to temperature extremes and light.
- Keep refrigerated and use within 30 days of manufacture.
- Culture up yeast if not at peak freshness.
- If over 1 month rejuvenate with SG1.020-1.025 half litre starter, cooled to 75°F before pitching.
- Use sufficient quantities.
- Double the pitching rate for every 0.008 above SG 1.048.
- Pitch at the right time.
- The high kraeusen stage 36-72 hours after making starter is optimum.
- Use the proper yeast for the beer type.
- Select the appropriate yeast for the style and the actual fermentation temperature. http://beersmith.com/Yeasts/Yeasts.htm
- More flocculant ale yeast = Clearer, maltier beer.
- Less flocculant ale yeast = Drier, estery, fruity beer.
- More flocculant lager yeast = Clearer, full-bodied beer.
- Less flocculant lager yeast = Drier, colder-fermenting, longer to be bright.
- Use the correct fermentation temperature.
- Culture yeast at 75°F, not fermentation temperature.
- Introduce the starter into your wort both at 75°F.
- Then adjust to proper fermentation temperature.
- Perform proper aeration.
- Lack of aeration: lag time increase, prolonged fermentation, high final gravities, Off flavours.
- At 75°F, no threat of oxidation from vigorous aeration, CO2 produced will purge any oxygen.
- More flocculant yeasts need more aeration.
- Keep your fermentation temp constant.
- The temp changes at night can result in premature flocculation and stuck fermentation.
- Don’t rack prematurely.
- Results in a high gravity.
- Wait until ~90% sugars are attenuated for a 2nd fermentation.
- Top-fermenting yeast should not be harvested until 50% sugars are attenuated.
- Avoid a prolonged yeast storage.
- Ensure that yeast cells are maintained in a minimal metabolic state, unaffected by stress.
- During storage, yeast uses endogenous reserves for basal functions.
- Depletion of these reserves due to a delayed storage and exposure to cold stress or ethanol stress may affect subsequent fermentation performance.
Dr. Heng-Cherl Yom