Guidelines for White Labs Pitchable Yeast Cultures

1. We concentrate our yeast 6-10 times more than other companies, so we can ship our concentrated yeast slurries in relatively small volumes. Each one barrel pitching rate corresponds to the same quantity of cells as one liter from other liquid yeast suppliers.
2. It is best to use the yeast while it is fresh, ideally within 1-3 days of receipt. We have had brewers store the yeast 2-3 weeks before use, and never have a problem. Always store the yeast at temperatures between 35-40° F.
3. For the first generation of the new yeast culture, a lighter style beer with a 10°–12° Plato gravity is recommended for best yeast performance. Servomyces Yeast Nutrient (available through White Labs) will help shorten the fermentation cycle and make the yeast healthier for subsequent generations.
4. Keep yeast in the refrigerator until needed. Do not freeze the culture. Remove yeast from the cold 1-2 hours before pitching, so the slurry can come close to room temperature. This makes pouring easier. To get the yeast from the package to the wort, sanitize scissors, cut the bottom corner of the bag, and pour in.
5. The fermentation is best started at 70-72° F (even for lagers), and lowered to desired fermentation temperature after krausen formation or CO2 begins. The initial signs of fermentation should be evident within 12-20 hours depending on how long the yeast was stored. The successive generations will have a shorter lag time and faster fermentation. The attenuation and flavor profile should be the same. The first fermentation usually takes 1-3 days longer to ferment to completion. The yeast has to adapt to new surroundings, particularly switching from a laboratory culture to a brewery fermentation culture. When repitching, one generally does so with more cells, producing a faster fermentation. More cells are needed when repitching because the pitching yeast becomes a source of contamination, since sterile conditions never exist in a brewery.