I am starting to brew larger batches (10-15 gal) and need to come up with a practical method for harvesting and repitching yeast. I tend to brew about once a month, so I usually have to store the yeast in the fridge for 2-3 weeks rather than simply harvesting and repitching directly into the next batch (like craft breweries do). A full yeast cake from one 5 gal carboy is more than enough yeast to ferment the next 15 gal batch. But after a couple weeks in the fridge, I'm assuming that I need to "wake the yeast up" before pitching. Should I...
1) just let the yeast warm up to pitching temp on brew day and pitch the desired quantity of yeast to my next beer?
2) add the desired pitching quantity of yeast (~300 ml, ~600 billion cells) to a small (1-2 liter) starter just to wake it up (not expecting growth) the day before brew day?
3) grow up a sample of the harvested yeast in an appropriate size starter, which I believe would have to be at least 3-4 gallons to get the 600 billion cells I need to pitch?
I'm leaning toward method #2, as giant starters are time consuming and expensive, but I've heard that lots of slurry in a small starter can actually negatively impact yeast health. Is there any truth to this? If I wake the yeast up in a small starter on the morning of brew day, can I avoid negative yeast impacts by limiting the time they have to grow and pitching the entire starter within 6-8 hours?
