Storing yeast questions

[doodoobutter]

Update, read post #7.

I have a lot of grain from a bulk buy to get through before it gets cold outside (north east). I use california ale yeast from white labs for a large portion of our recipes. I want to take a vile, and make a bunch from it to store. After some reading, this is the plan that I came up with, I took what I needed from different turorials:

I'm going summarize so this doesn't turn into a novel, let me know if you need more info.

1) Split vial into (2) 1 gallon glass jugs, filled with 4oz dme and 1 qt water each. Basic starter gravity.

2) After 48 hours, add another 4oz dme and 1qt water.

3) After 48 hours, add another 4oz dme and 1 qt water.

4) Let finish fermenting for a few more days.

5) Boil some 8oz Ball jars and lids. When I take them out, leave about half full of water and screw on the tops while hot.

6) Cold crash starters for a day or 2. Then take them out and decant 90% of the spent wort. Then swirl the slurry around to make it somewhat homogeneous. Use it to top off the jars that are half filled with sterile water.

7) Refrigerate my little bottles of yeast. Then take one out 48 hours before brew day, and make a starter.


Ok, this looks good to me except one thing I came across while researching, botulism. I know it has come up before with boiling wort for storage instead of using a pressure cooker. But I feel like I might be doing something a little unique here. I could just store the yeast in its own spent wort, and that would be as safe as storing beer. But I thought that storing it in sterile water would be more healthy for the yeast, as opposed to storing it in it's own spent wort which contains some alcohol. Buuuut, sterile water is going to have a higher ph than spent wort, putting into botulism territory.

Am I looking into this too much? If there is a risk of botulism, I'll just store on spent wort and get a pressure cooker in the spring when we start brewing again.

I should also note that I left out a lot of my sanitary procedures in the steps.

 

[HumulusHead]

I'm basically wondering this same thing. I poured a whole yeast cake into a sanitized growler and put in my fridge about two months ago. Haven't used it, wondering if it's worth it or not.


Sent from myPhone

 

[LLBeanJ]

Your plan is fine and will work well. It's very similar to how I store yeast and I can attest that it will keep for several months. Also, the yeast will stay "fresh" longer if stored under its own wort, as opposed to sterile water, so don't bother to decant once the starters have finished out and you are ready to transfer to sanitized jars.

Edit: Let me also add that you don't need a lot of yeast to start with. I only keep one jar at a time and I make my starter from it as I need it. I just make it a little larger than I need so that I have 25-50B cells left over to pitch. Also, if avoiding having to make fresh starters for every brew is a goal, plan your brews so that you can pitch slurry from the previous brew. That way, you make an oversized starter, pitch most of it and save a little for later, then use the slurry from the first pitch to inoculate another batch of beer. I do this all the time and it work beautifully.

 

[doodoobutter]

Sounds good. I think I'll just use my method and change one thing. I'll decant maybe like 70% of the liquid off so that I'm left with a slurry and just store that as it is.

@HumulusHead, it depends a lot on how sanitary you were when you poured the cake into the growler. You will have a lot of trub in it though, you should be washing the yeast. I have washed yeast, and it's a pain, and you still have trub, hops, and alpha acids that get added to your next beer. That is why I'm going to start cultivating yeast straight from the vial that I buy from the lhbs using this method.

On a side note, when I wash yeast, I mix sterile water with the yeast cake and start decanting the suspended yeast into jars. I guess that would have the same safety concern of botulism that my method has since you would be storing something with very little acidity.

With this method, I'm basically washing the yeast, minus the washing part because it's not needed.

 

[HumulusHead]

Ah that makes sense. I've read that it's not a big deal to pitch a wort on a fresh yeast cake and you can store it for short periods of time. I just did this out of a time savings stand point. That totally makes sense tho with the trub and hop residue affecting flavors. I think I'll just dump it and not risk ruining a batch, since I planned a totally diff beer then that yeast cake made.

I'm going to need to look into more of what you are doing more

Thanks for bringing this to my attention. It seems more sanitary and clean (flavor wise) to just start growing right from the original vial.


Sent from myPhone

 

[doodoobutter]

I think it is only a big deal if you are saving the yeast from a really hoppy beer and then brewing a lightly hopped beer. Or if you saved the yeast from a stout and then you're going to brew a light colored / flavored beer. The color and flavor will carry over.

You want to use your method when brewing the same beer, or something stronger in flavor and ibu's than the last beer so that it overpowers.

 

[doodoobutter]

Update: Didn't work as well as I had hoped for. First, I'll admit, I haven't started using a stir plate yet. After all of these years brewing, I now see why everyone uses them. Without them, you get nothing, and I'll be getting one right away.

I ended up with almost nothing more using this method, than what I would get from doing a normal, 2 liter starter.

It would be more efficient to just brew up a 10 gallon batch at 1.040, make a 2 liter starter from a vial, and pitch that into the 10 gallons (throwing away 10 gallons of light, unhopped beer). Store it in sterile, Ball jelly jars, and use a stir plate to make a starter from your stored yeast.

There it is from my experience, that's what I'll do from now on. You generate a yeast cake that doesn't need to be washed, there are no hop particles, and very little trub. Do this and you are set for many batches imo.

 

[flars]

Without decanting the original spent wort(s) you were diluting the second wort and again the third, and so on.
The second addition of 4 ounces of DME would effectively have been in 2 quarts of water, reducing the OG by 50%. The next 4 ounces of DME would have been diluted in 3 quarts reducing the OG even more.
Decanting the spent wort for each step would have resulted in the growth planned.