I brewed an APA with WLP001 two weeks ago. I just racked it to a Secondary carboy and saved 800ml of yeast slurry from the Primary carboy. I want to brew an Am IPA Saturday and reuse this yeast in it. Is the 800ml slurry too much, too little? Any other suggestions? Thanks, MK
Depends on the batch size and gravity of the beer to be made by it. I usually pitch about half a slurry from a lager and a third of a slurry for ales, if the same volume and same ABV. If a slightly bigger beer, then half a slurry from a smaller beer…800 ml is a lot of slurry for an ale…I would go with maybe 500 ml of good, clean slurry for what you are proposing. If you have a fair amount of beer in your slurry, then that might increase the amount you need to use. I pour off the beer at the point I pitch the slurry. The slurry starts to lose viability at a rate of 50% per month or so (possibly greater for some strains). This is all anecdotal, so YMMV on these aspects, but generally what I use to estimate things.
I’d recommend that you use a pitch rate calculator like mrmalty.com. That should eliminate the guesswork and give you an ideal recommendation for the beer you’re brewing.
+1. it’s hard to say without seeing the slurry as well. How stiff/loose is it? how much non yeasty junk is in it. 800 ml is too much almost certainly but I don’t know how much too much.
It will be three weeks old, so I would restart by putting about 75-100ml in a 2000ml stired starter. Three weeks isn’t a huge long time, but I’d restart it just to be sure. My procedure is to direct repitch if it’s been a week or less, restart if longer
well, it’ll be three weeks from pitching but only a week from harvest. given that all my beers stay in primary more than a week it would always be a restart according to that procedure. You will probably get a younger population with a starter and assuming you gave them nutrients and enough o2 they will be raring to go but the harvested slurry is going to be just fine without a starter.
according to mr malty, 5.25 gallons of 1.065 ale wort with yeast harvested four days before brew day at the thinnest and most junky setting you want ~300ml. At moderate thickness and moderate junkiness you need only 100ml
Misread the OP. I thought he racked to secondary two weeks ago… I restart if I have harvested the yeast more than a week before