Frozen Yeast?

[MrBIP]

Concerned that my vials of yeast may have gotten frozen in shipment and/or sitting on the front porch for a few hours when delivered. When I cracked the lid on my WLP007 Dry English Ale Yeast, I got just the faintest of fizz and it was very thick, "gloppy". It just didn't act right or look right.

If that happened, will it still be viable? Can I trust the starting cell count based on date for calculating starter? Or, if it was frozen, will it be reduced?

 

[Nosybear]

English yeast always looks a bit gloppy and the fizz is possibly an indication of viability. Make a starter. If it works, your yeast is good.

 

[Ozarks Mountain Brewery]

I've lightly frozen wort and yeast by accident keeping them in the deep freeze too long, its fine as long as its given a slow warm up

 

[MrBIP]

Starter is going, so we'll see.

 

[sbaclimber]

Starter is going, so we'll see.

I've been using WLP007 exclusively for the past 2+ years.
The "fizz" can happen, and I even had the "gloppy" for the first time the last vial ordered.
So far, no dead yeast!
The gloppy definitely acted differently in the starter, but still produced the amount of fresh healthy yeast I needed for my brew. The yeast I harvested from that brew has acted absolutely normally for the following 2 brews.
So, in other words, RDWHAHB

 

[MrBIP]

Well, it appears to be fine, starter is looking like it should.
When that WL vial didn't fizz out aggressively like they always seem to do, I really thought it was bad. Usually have to be really careful and open those very slowly so as not to make a mess of it.

 

[Bishop on the Moor]

A small tangent on the freezing yeast thread.

I froze a whole fridge of newly conditioned beer. Not intentionally. I thawed it, reprimed it and rebottled. There was enough active yeast still there to carbonate it all a second time.

 

[Foster82]

The main issue is if you freeze your yeast solid. Ice crystals form in the cells and cause them to burst, thus killing the yeast. The initial freeze is not always a death sentence, however multiple freeze and thaw cycles is extremely deadly. If there was still some liquid in the vial, brew on.