I mostly brew small batches – 2 gallons or less. I’ve done ok using a full pack of dry yeast, but I’m wondering what would happen if I just used a full pack of, say, Imperial. They quote 200B cells per pack – that’d be like a 4x over pitch according to Brewer’s Friend.
If bad things would happen, what would be the best way save half a pouch of yeast between brew days?
Those pitch rates are not equivalent. I wish that people would stop using pitch calculators because they are flawed. The difference between 100B and 200B cells is one replication period, which is in the noise with respect to pitching rate. What matters is yeast cell health and dissolved O2. If we pitch 100B cells into a 5-gallon batch of wort, I can assure you that dissolved O2 in the wort will play a role regardless of if the yeast is dry or liquid.