My yeast cultures/storage time.

[BrewStooge]

Hi all, I was recently cleaning up the recipe list, trying to get a schedule and a go-to set of yeasts set up. Well I think that's worked out, and I just wanted to get some feedback on my yeast procedures.

What I've done for a while here is I started with one vial of yeast (currently 8 types in store), make up a starter, and just before brewing I pull a sample off the starter and create a new one with that for storage. Each starter is the same, just plain water/dme, usually in the realm of 1.050. The way I figure, this should keep a pure yeast strain unaffected by the beer it was used to brew, and generally pretty trub free (being pulled from a flask on stir plate that was just turned off a minute ago or so).

Anyhow, to cut the rambling short, would you consider these samples to be effectively 'pure' representations of the original, and how long has anyone stored these (I use sterile mason jars myself) and still had it be good?

On a separate note, I've also taken to the idea of making bulk starter wort, and storing that in jars as well. Being put in hot and let seal as any normal canning would it seems about as safe as any home canning could be. Any thoughts on that? Cheers!

 

[insurgus]

As far as the starter wort, canning works great. I go for 20 minutes at 15psi. Likely a bit overkill but it works.

For the yeast, I slant all of mine straight from the package. I have better luck that way as there's less chance of infections from nasties. I'm currently running 32 strains in a frozen yeast bank and so far, they all seem healthy.

 

[theredben]

BrewStooge - you will encounter less of a contamination risk if you take a number of vials at an earlier stage and use them over time. But before we can help you much more, we need to know what you mean by "vials"?

 

[BrewStooge]

I generally use WhiteLabs yeast, I currently have 8 strains in storage, so one 'vial' from them. Pretty much what I do is similar to the common washing, but I re-breed and 'wash' from the starter rather than the brew. I guess the bigger questions would come in on the age factors. Such as the one I started up the other day, it's still alive (even if it took a day and a half to start up) but it had a bit of a vinegar smell on opening it. I'm guessing there may have been some autolysis since it hadn't been used for several months before (near a year actually) but since it's still alive would you still give it a pass?

 

[bigljd]

I started slanting yeasts this summer and I love it. It's pretty easy you've gone thru the process once. Here's the thread on how to do it:

https://www.homebrewtalk.com/f163/slanting-yeast-133103/

You can also click on the link in my signature and I've documented my process, although it's mostly the same as the thread above.

 

[Jbear]

I also harvest yeast from my starters also and have been happy with the results. It just seems far easier to me to make an extra .5L on my starter and pour it into a mason jar than to wash yeast post fermentation. Additionally, I tend to make stronger beers a lot and everything I've read on yeast washing indicates you want to wash from lower alcohol beers so you get healthier yeast - my starters are about 1.040...

As far as storage time goes. Personally, I only keep a few strains so that I turn them over at least every 3-4 months. If its a strain I use less often than that, I just buy a pack. Of course, I do that more for the domestic peace which comes from having fewer mason jars in the fridge... I think you can go much longer without worry, some of the cells will die but you should have enough viable yeast to reculture. As long as you are making a good sized starter and allow it enough time to fully ferment out you'll have all the fresh yeast you need.