If a vial of yeast is at room temperature for 3 days then put back in the refrigerator, is it still viable?

Question

If a vial of yeast is at room temperature for 3 days then put back in the refrigerator, is it still viable?

2010年12月10日 12:48

I live in an apartment and didn't receive notification that my yeast had arrived for 3 days after it got to the office. Normally, I'd just toss the vial of yeast and go to my LHBS to get more, but this is the Antwerp Ale yeast (Platinum Strain, not currently available at my LHBS).

Though I had an ice pack shipped with it, the yeast vial likely sat there for 2-3 days at room temperature before I was able to refrigerate it.

Is the yeast still viable? I'll be making a starter but would prefer not to have to make a brew day run to get multiple vials/pouches of replacement yeast in lieu of a starter.

Thanks!

Topic viability yeast homebrew

Category Mac

brewchez · Accepted Answer · 2010年12月10日 12:48

It'll be fine if you work off a starter. I'd also recommend planning a second batch with some harvested yeast from the cake. Certainly after the primary is done with the first beer, you'll be back to a good amount of healthy yeast in the cake. So planning a second batch will be a nice comparator, and you won't have wasted the platinum strain should the first batch be sub par.

Brandon · Accepted Answer · 2010年12月10日 06:03

The yeast should still be mostly viable, but a viability test would be needed to confirm. If you don't have methylene blue and a microscope, then you'll have to assume a viability level. I would think an assumption of 75% would be fine, along with careful monitoring of your starter.

Should your starter not propagate correctly, you could also always leave the boiled wort in a sanitized vessel while you wait for a new shipment of yeast. Were it me, I would prefer the slight risk of contamination over brewing with the wrong yeast.

Denny Conn · Accepted Answer · 2010年12月10日 03:15

1

Denny Conn answered at 2010年12月10日 03:15

I think it's likely still pretty good. You'd want to make a starter with it in any case, and that will give you a good indication of viability.

baka · Accepted Answer · 2010年12月10日 02:35

There are probably still some viable yeast cells in there. You may need to build it up a couple of times to get a pitchable number of cells, though. Also, there's no telling which cells are still alive, so it may wind up with a different character from what a well-treated vial would produce.

I'd try it and see what happens.

If a vial of yeast is at room temperature for 3 days then put back in the refrigerator, is it still viable?

About