Storing yeast: lesson learned

[Simonh82]

I went to make a starter today for a brew I have planned. The yeast had been built up from a vial I received for �£3 from Wibbler Brewery. I'd been storing it under beer in a screw top kilner jar in the fridge.

I discovered today that you really need to leave some head space when you store yeast. I filled the jar to the brim and screwed on the lid. Clearly the wort hadn't finished fermenting completely so as soon as I cracked the lid the liquid started fizzing. The yeast layer immediately shot back up onto suspension with the CO2 released and any chance of pouring off the spent wort disappeared.

Now my started is twice the size it should be and half made of spent wort.

I'm going to do a second step to build it up further before pitching.

 

[TartanSpecial]

I keep my cultured & harvested yeasts in the fridge in 1 ltr tonic water PET bottles with wort on top. I noticed some continue to be active for a day or two or three despite being in the fridge, so part of my breakfast routine is to squeeze each of them (I have 4 yeasts on the go) to check for pressure build up.....and vent if necessary.

 

[Simonh82]

That sounds like a good idea. I did vent it a couple of times after putting it in the fridge but I thought it wouldn't carry on fermenting for long. It also spent 3 days at room temperature after fermentation subsided before going in the fridge.

I think the issue is that the co2 was forced into solution so as soon as I cracked the lid it went crazy. With a bit of head space it should be fine.

I don't think I could keep my yeast in litre bottles. Between the three jars of beer yeast, one large sourdough starter and many rolls of film (my other hobby), space is at a premium in my fridge and each new addition brings a deeper frown from my missus.