Re-chilling yeast vial - Bad or does it not matter?

[MockY]

Tonight I was making a starter as I so often do, but this time near the end of chilling the starter wort, I accidentally bumped my 2L erlenmeyer flask into the sink wall while whirling the flask one last time. I could hear a discrete *clunk* in the ice water followed by a rapid change in color. The few seconds it took to realize what happened while watching the water turning orange/brown, was excruciatingly painful. Lifting the flask shortly after confirmed the nightmare as a piece of the bottom was clearly missing.

So now I find myself without a yeast starter, no erlenmeyer flask, and an uncomfortable feeling of disappointment with a hint of anger. I also have a vial of yeast that's been sitting on my kitchen counter for 5 hours. An occasional shake during that time made sure all yeast were constantly in suspension. These poor yeast cells were ready to roll but are now back in the fridge.

So finally to my question (I'm typing in disbelief and get a bit carried away):

Agitated yeast in unopened vial that's been at room temp for a few hours... what damage am I causing to these little helpers by shoving them into the fridge again? I'm creating a new starter tomorrow after I get a new flask but should I replace the yeast or should I simply "thaw" them up again tomorrow when I attempt to make another starter?

 

[rupert130]

You are probably good. At warmer temps their metabolism increases, but since you are making a starter anyway I doubt the somewhat depleted energy reserves will make any difference.

 

[WoodlandBrew]

Putting them back in the fridge was probably the best thing you could do since you didn't have the resources to make a starter.

When the yeast warms they begin metabolizing their glycogen reserves. If they were left out they would deplete these reserves and begin to starve resulting in cell death that would reach about 50% in a few days.

Putting them back it the fridge will slow the metabolism back down and conserve what is left of their glycogen.

I agree that it probably isn't going to make a big difference in the end. The lower glycogen level may lead to a little slower start of the starter.

 

[eadavis80]

While I know you have a White Labs yeast vial and not a WYeast Smack Pack, I would assume this still holds true. It's from WYeast's FAQ on their website: 8. I popped the inner nutrient pouch and the package swelled tight but I can’t use it right away. What do I do?

If you have activated a package but can’t use it right away, simply allow the package to swell and then refrigerate the package. The yeast will survive for extended periods if refrigerated. Before using, take the package out of the refrigerator and allow it to come up to room temperature before using. It is best to use the yeast as soon as possible.