Old Washed Yeast

[GDoucet]

Hey guys, I’d like to get some advice on reusing some old washed yeast.

I pulled out a jar with about a teaspoon of yeast slurry that I washed a year ago and made a 1.5L starter with it on Monday. I didn’t see any yeast activity until Wednesday morning and it probably won’t be fermented out until tonight (Thursday night). This seems to be going much slower than I’m used to but I’m thinking this has to do with the age of the yeast. Because of the age and lag time, I’m guessing there weren’t many viable cells when I made the starter meaning the starter was really underpitched. If I turn around and decant and pitch this yeast directly into my wheat I’m brewing this weekend, will the yeast have a tendency to produce any of the off flavours associated with underpitching assuming I’m pitching the right amount in my beer? Is this yeast going to be healthy for my brew evethough it was underpitched?

[jeffsmith]

I'm thinking you might want to cold crash, decant and pitch it into another starter to make sure you have a nice, healthy amount of cells. Also make sure that you're not getting any nasty aromas from the new starter, that would be a pretty good indication that you wouldn't want to pitch that yeast.

[chalmers]

Agreed.

[GDoucet]

Thanks for the help. I was originally planning on doing a two step starter but because of the lag time in the first, I won’t have time to cold crash and decant the second starter in time for my brew day on Sunday.

It seems to me my only option now is to cold crash tonight, decant and repitch tomorrow in another starter and let it ferment up until my brew day on Sunday and hopefully it will be at high krausen by that afternoon and pitch the entire starter.

I’ve never pitched the whole starter before, only cold crashed and decanted. Have you guys had good results doing this? I was planning on doing a 2L starter for the second step and my final batch size is going to be 23L. Maybe if I’m going to pitch the whole starter, I should use dried wheat extract for the starter since I’m doing a wheat beer.