From Wyeast Website - Yeast Harvesting / Re-Pitching
When Yeast Should be Harvested
The timing of cropping will have effects on the quality and density of the slurry. Consistent timing of harvest will help maintain the desired characteristics of the culture.
* Cylindroconical and Dish Bottom Vessels (Bottom Cropping): Yeast should be harvested once the temperature has dropped below 40°F (4°C) and trub has been discharged. This will insure a large yield of clean, homogenous slurry.
* Open Vessels (Top Cropping): Yeast can be harvested once the gravity has dropped below 50% of original gravity. First head will rise approximately 24-36 hours into fermentation. Discard 1st skim (“dirt skim”). A clean, 2nd head will rise which can be harvested with a 2nd skim.
-St. Louis Brewing Group on HBT
Fermenting- Dark Crystal ESB, Vanilla Poter, Oatmeal Cookie Ale
On Tap - American Amber, English Pale Ale, Deception Cream Stout
I work for a few billion single cell organisms. I feed them and keep them happy. They pay me in beer!