White Labs lager yeast tips
Lager yeast strains are unique, because they ferment beer wort at temperatures between 45° F and 55° F. Even though they can ferment at these temperatures, they work slower than ales fermented around 68° F. When fermenting lagers at true lager temperatures, you will need to pitch 2 to 3 times more cells than you would when fermenting ales. Our lager strains are supplied in the same pitching rate as our ale strains. Therefore, you must practice one of the four options on the following page:
1. Order two times the amount.
Order twice the amount (i.e. 15 Bbl. For 7Bbl) and start at your desired fermentation temperature.
2. Start fermentation at ale temperatures.
Order the corresponding barrel size for your system (i.e. 7 Bbl for a 7Bbl system). Maintain fermenting wort temperature at ale temps (about 68° F) until signs of fermentation are evident (i.e. CO2 evolution). Begin to lower temperatures to desired fermentation temperature. Lower 10° F over each 12 hour period until temperature is reached. For each succeeding generation, repitch as per #4. Flavor effects of this method vary with yeast strain, recipe, and palette. Most of our customers report little or no flavor effects of starting fermentation at higher temperatures.
3. Propagate yeast 2-3 days before using.
This cannot be done the same way as for ales. For a 14 bbl brew, purchase at least a 7 bbl pitching rate from White Labs. Grow this in 2 bbl's of wort that closely approximates the wort that will be used for the lager. Maintain temperature of propagation at the same temperature of desired lager fermentation. After 50% attenuation (2-3 days), top off fermentor to 14 bbl.
4. Repitch with 2 to 3 times ale pitching rates.
Once the yeast is in the brewery, high pitching rates can be accomplished with repitching. Collect 2-3 times the normal slurry from a completed fermentation and use to repitch the next batch. Cell counts should be about 30 million cells per ml of wort.