Froze yeast on accident

I always have a packet of yeast in my refrigerator in case of emergencies; a packet of US-05. Do you have something like this?

I would suggest that you give your fermentation a bit more time (24-36 hours) to see if fermentation ‘kicks off’. If after that extended time you do not see signs of fermentation I would suggest adding some more yeast to the fermenter (which would be the packet of US-05 for me).

Cheers!

P.S. Dry yeast is perfect for emergency reasons since it last for years when stored in the refrigerator.

 

At this point, since you already used it, I'd probably wait and see. Contrary to popular belief, yeast can survive freezing, at least some percentage of them.

But...one concern could be underpitching. Was this a single vial/smackpack? Into what wort? If one pack would have been underpitching, you can bet that frozen/thawed yeast would be even more underpitched.

 

5 gallons of what gravity?

 

By most calculators, a single smack pack would be underpitching for your batch size and gravity. By the dumbed down instructions that appear on yeast packages/websites, it's plenty. That's before taking into account your spillage and freezing losses. Still, I would probably just ride this one out and see.

 

Don't feel like your alone. I have also done this. I had to pitch more yeast. Good luck!

 

Wild yeast survives freezing temps every year and still returns the following warm season. This selects for stronger individuals (at least freeze resistant) but will kill off a percentage of the yeast as well...natural selection at its finest. The real problem is that you don't know if the surviving yeast are more or less fit at reproducing and fermenting, which can't be assumed just because they survived through the temp extreme, and is the most important piece of info to determine if you have enough active yeast for adequate fermentation.

So there will certainly be some viable yeast that survived the freeze, but the percentage of viable cells can't really be calculated, nor can the fecundity (reproductive success) of the yeast. That's why folks are telling you to let it ride out and see what happens first before pitching more yeast. You very well may have enough yeast to take care of this batch, and then again you may not...there really isn't a way to know for sure until you allow the yeast you pitched to get underway and do their thing.

Did you use any yeast nutrient? This can help a little with underpitching or slow fermentation and can be added to the boil or in the fermenter for slow fermentation.

 

If you are the kind that needs reassurance that your yeast are doing their thing you have a few options.

Wait a few days, three max, and see if there is any activity. Bubbles in the airlock is not always the recommended indicator since gas can escape elsewhere while fermentation is occurring but for this purpose it is fine. Once you see bubbles you are making beer. The yeast is.

Get another package of yeast, let it warm to the temp of the wort and pitch the yeast. You underpitched anyway so more yeast is recommended if you can swing it. And you'll feel better.

Or pitch two packages of US-05. You do have US-05 right? The best, always works, classic, fool proof yeast. Get some.

Cheers.

 

Bubbles (or lack of) are not a reliable indicator. Are you fermenting in a bucket? If so, open the lid, peek in, and see if a krausen has formed. I would wait maybe 48 hours from when you pitched to check.

 

Are you fermenting in a bucket or in sobering you can see through? If it's see through, you can see the yeast actively fermenting and mixing the wort/swimming around while active fermentation is taking place. This is the indicator you want to see, along with airlock activity. Ultimately, you will need to take hydrometer readings to determine if you've reached final gravity...if after fermentation occurs and you haven't reached your final gravity, then I'd add more yeast.

 

I don't see a need for 2 packs of 05...over the last 4-5 years of using 05 as my main yeast, I only use 1 pack for my beers that go up to around 1.060 OG and have never had any issues with underpitching. I think too many are a little obsessive about underpitching when it rarely occurs except in higher gravity beers. At least that's my observation after brewing for over 20 years.

 

If you see the described activity, let it ride...if you see nothing happening at all, then go ahead and add the 05. If no activity at all, then no need to check with hydrometer...if activity, wait until fermentation is complete as usual (krausen fall) and yeast settles in the bottom, then check gravity.

 

One pack of US-05 (11.5 grams) would be about 230B cells, which if fresh is more than enough for 5 gallons @ 1.060, by just about anyone's reckoning.

I think that would depend on what's defined as under pitching. In your example, and with the OPs batch, I don't know anyone who would say a pack of US-05 is under pitching.

OP: An 11.5 gram pack of dry yeast contains more than double the cell count of a smack pack or vial.

 

Somewhat personal preference. But also, liquid yeast is available in a staggering variety of strains. Dry yeast isn't.