Each vial of White Labs liquid yeast is designed to be used directly in 5 gallons, hence the term "pitchable yeast." Each vial is equivalent in cell count to a pint starter, or 75-150 billion cells. One vial will usually start fermentation in 5 gallons in 5-15 hours at 70oF. If a faster start is desired, or if initial gravity is over 1.070, we recommend a 1-2 pint starter be made.
Directions for Use:
Store in refrigerator until use, do not freeze. Remove 2 hours prior to addition and let warm to room temperature (~70o
F). This makes re-suspension in the vial easier, and prevents a temperature shock when added to wort. Remove the shrink wrap on cap, shake the vial well to re-suspend yeast, and open cap carefully.
Important! Package under pressure, hold the vial upright and loosen the cap a little at a time to relieve the pressure slowly
Pour into fresh, aerated wort (by shaking fermentor for 15 minutes or injection though an aeration stone) at 70-75o
F. The first sign of fermentation will be a raised airlock, then wisps of foam will start to cover the top of the wort. A full, thick krausen will be evident 1-2 hours after this. Be careful to leave enough head space in the fermentor, or use a blow off tube because some fermentations will be very active, and it is not unusual for a 5 gallon fermentation to blow the airlock off a 6.5 gallon fermentor! When fermentation activity subsides, check the gravity. If fermentation is complete, bottle the beer or transfer the fermentor to 40o
F for 1 week to cold condition. Bottling or transfer to cold should take place 14 to 30 days after brewing.
Shelf Life: Yeast is a living organism. As such, it needs to be in the right conditions to survive. Dry yeast can stay alive for one year, but yeast left in liquid form, even though it's a better product in terms of taste and performance, is more perishable. At White Labs, we are constantly working on our recipe to maximize the viability of the yeast in long term storage. The longer we can make the yeast last in the vial, the better shape it will be in for fermentation. After 30 days in the vial, the viability of our yeast is 75-85%, which is very high for liquid yeast. Yeast that is harvested after a brewery fermentation will typically have a viability of less then 50% after 30 days. Our high viability is due to the health of the yeast and nutrient content of our liquid at packaging. After 6 weeks, lag time before active fermentation is usually between 15-20 hours. The shelf life for White Labs Yeast is four months. Yeast used after this point is usually fine, but lag times will be longer. There will be living yeast in most vials for 6-12 months, so if a starter is made to activate the yeast, successful fermentations can be carried out with aged yeast.