I’ve never tried resurrecting one that old. Most I’ve done is a year old. But I’ll bet you can do it. I wouldn’t be discouraged if there’s no obvious activity from the initial step. It’ll probably be so minor that you’ll miss it.
I’ve built back up from stored slurry after 17 months, so if your yeast was in the fridge the whole time I’m sure you’ll get some viable cells from it.
IMHO your starter is way too big though. I’d start with 50-100 mL, and step up three or four times to get to a pitchable quantity.
I haven’t seen much activity, but this is what it looks like 24 hours later.
Since I obviously started this off incorrectly what would be the correct course of action? Take a gravity reading and step up? I was thinking of swirling it…
After just 24 hours with yeast that old, it’s way too soon to step up. Give it a couple more days to “wake up”. Swirling certainly wouldn’t hurt anything, though.
So it’s been more than 72 hours. Swirled it a number of times before and after it started fermenting. Never actually foamed but bubbles were vigorous so it looks like it’s done. How do I make sure and how should it be stepped up from 2 cups?
I’d like to take a refractometer reading. Can I use this to calculate ABV? I remember reading somewhere that it doesn’t work that way.
I would crash cool it, then put it into a gallon of something less than 1.040. Maybe add half a pinch of dap+yeast extract.
The problem with a refractometer reading is that the presence of alcohol interferes, and none of the spreadsheets that calculate based on OG work very well in my experience. After you cool it and pour off the sup you can measure the FG of that.
Well, 2 cups is a pint, there are 8 pints in a gallon, an 8x jump is fine. If you’d like to go smaller you can, it’s up to you. Since it’s shaken instead of on a stirplate you can drop it down if you like, but I wouldn’t go down as low as 1/2 gallon unless you feel like the yeast really need to be babied. I know this was an old smack pack, do you feel like you got good growth in this step? If you’re worried about it do 1/2 gallon, at this point you’re in the best position to asses it.
Do you see the very thin layer of white yeast above the brown layer. I believe that is new growth. I suggest decanting the wort and adding some fresh 1.020-1.030 strength wort and shake intermittently for a day or two and repeat.
I crash cooled for 24 hours and decanted per Tom’s advice. Made up 3 qts of 1.033 wort with 3/4 tsp yeast nutrient.
Recalling back I just used RO water for the initial 2 cups. No calcium etc… This time I diluted the RO with some unsoftened tap water to get minerals in there.
So the grower is 3/4 full and hopefully will be a bubbling when I get home…