Each vial of White Labs liquid yeast is designed to be used directly in 5 gallons, or "pitchable". Each vial is equivalent in cell count to a pint starter, or 30-60 billion cells. One vial will usually start fermentation in 5 gallons in 5-15 hours at 70°F. If a faster start is desired, or if initial gravity is over 1.070, White Labs recommends a 1-2 pint starter be made.
Homebrewers that enjoy yeast culturing - If a starter is made from a fresh vial, one vial can be added directly to a 2 liter starter, which in 2 days will grow to approximately 240 billion cells, to achieve a pitching rate in 5 gallons of 1 million cells/ml/degree Plato (with a 12 Plato beer).
Directions for Use- Store in refrigerator until use, do not freeze. Remove 2 hours prior to addition and let warm to room temperature (~70°F). This makes re-suspension in the vial easier, and prevents a temperature shock when added to wort. Shake the vial well to re-suspend yeast, and open cap carefully. Pour into fresh, aerated wort (by shaking fermentor for 15 minutes or injection though an aeration stone) at 70-75°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!
Please note: High Gravity cannot guarantee the viability of liquid yeast if it fails to work unless it was purchased with a cold pack.