I used WL530 to brew Patersbeir extract 5 gallon batch. Did a starter and the OG was 1.047 and FG was 1.045. Used the whole yeast cake for velvet rooster extract with OG of 1.079 and FG of 1.019
I would like to brew another batch of the Patersbier - can I harvest and use the yeast again?
Also given the Patersbier is a lower FG I assume I only need to use about a 1/3 of the yeast cake - is this correct
You can harvest and reuse the yeast as many times as you want, provided the yeast is healthy and not too stressed. Stress can be caused by under-oxygenating the wort before pitching, by storing the yeast too long between batches, or exposing it to high temperatures or alcohol levels. Some people say you should never pitch from a higher alcohol beer into a lower one, but I’ve not found that to be true. As long as the high alcohol beer didn’t get within a couple percentage points of the alcohol tolerance limits for the yeast, there shouldn’t be any problems.
And yes, about 1/3 of the yeast cake is about right for a “normal” 1.050 OG beer.
