Pitching on really old slurry harvest

[meaty32]

I found some old slurry that I harvested, cleaned and have stored in a refrigerator for the past three or four years. What would happen if I made a starter and used it in a batch? I think it's American Ale yeast.

 

[eadavis80]

I don't know what would happen. My GUESS is because the yeast's age, it's probably not very viable anymore and it would take 3-4 step ups to get that yeast going again. You'd probably have to start with a very small (in volume and OG) starter and gradually build them up. You could try it as an EXPERIMENT for fun, but I would not use yeast that old in a batch for fear of ruining all that beer. I'd spend $4 and get a new pack of 05 for my next batch.

 

[Biobrewer]

I would just do a small scale test fermentation. If you get good attenuation and the character you'd expect with no off flavors, let it rip!