Awakening aging yeast - longer shelf life?

Since I've decided to start washing yeast, I've been thinking about how to get the most out of it. I've read that most say yeast can only be kept for a few months, or a year at best. But what if we were to awaken the yeast every few months with a starter and nutrient, wouldn't that allow the yeast to multiply, creating new yeast cells and allowing us to keep a strain longer, if not indefinitely?

Or can a strain of yeast be used only a limited number of times, even if they are allowed to reproduce every so often?

I understand that by leaving a colony of yeast in the fridge over time will eventually kill off all of the yeast, but it seems that an occasional starter would help keep the yeast healthy, and also give us the chance to decant the older yeast cells that would fall out of suspension quicker than the healthy ones.

Is this right, or am I missing something?

Last week used a 13 month old washed Wyeast 1968 successfully. For the first time used home-made stir plate with a glass coffee pot, siphoned off 2L of wort and added the washed yeast. 22 hrs later the starter smelled very yeasty so pitched at 70F, 12 hours later(40 total) there was some foaming starting in a OG=1.044 beer.

Previously in the washed yeast thread successfully used a one year old Wyeast 1028 without a stir plate just swirled the starter.

Both of these older yeasts were washed twice to capture only the white yeast layer without any viewable trub. Topped up clear beer bottles 100% full with distilled water then capped. Stored in a very cold beer fridge.

At one year old both of these washed yeasts had developed some darker patches and looked close to expiring so created a new washed generation. Had read somewhere a fellow going two years successfully with a washed yeast. Am going to keep aging a 1 year old washed bottle to see how the color changes over time.

I have a Bock fermenting now. The Yeast has been in the fridge since July 2010.

So those that say yeast can be kept a year at best are wrong?

What about the number of uses? If properly maintained, can yeast strains be used indefinitely?

I successfully used 2 year old washed yeast. I can't remember what type is it was, but I used two jars just to make sure I got things going. I tried it with another 2 yeasr old yeast, but that one didn't start up at all. So, it can be hit or miss.

The next time I wash my yeast, I plan on using them earlier (6 - 9 months) and wash another batch at that time. Everything depends on what yeast you have, how many you really need in a bank, and what beers you brew.

I am considering getting the equipment and slanting some for longer storage.

Bombo80 said:

I successfully used 2 year old washed yeast. I can't remember what type is it was, but I used two jars just to make sure I got things going. I tried it with another 2 yeasr old yeast, but that one didn't start up at all. So, it can be hit or miss.

The next time I wash my yeast, I plan on using them earlier (6 - 9 months) and wash another batch at that time. Everything depends on what yeast you have, how many you really need in a bank, and what beers you brew.

I am considering getting the equipment and slanting some for longer storage.

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For the two year old yeasts, what if you had added them to a starter every six months? Not near as involved as slanting, but it would give the opportunity for the yeast to awaken and reproduce, giving you a younger colony.

Slanting certainly has it's advantages, but I'd rather not invest that much time and money at this point. I think I'll give my method a try and see what results I come up with.

Honestly, I thought this subject would have sparked a little more discussion.

TheZymurgist said:

For the two year old yeasts, what if you had added them to a starter every six months? Not near as involved as slanting, but it would give the opportunity for the yeast to awaken and reproduce, giving you a younger colony.

Slanting certainly has it's advantages, but I'd rather not invest that much time and money at this point. I think I'll give my method a try and see what results I come up with.

Honestly, I thought this subject would have sparked a little more discussion.

Click to expand...

With a name like that you should be telling us how to do it, not asking.

I don't know how slanting could be any more time intensive than you re-starting yeast for years. What if at the end of the year or years the yeast is bad? You just wasted years on this. Instead of the hour or so for the slanting.

And if you want to do this on the cheap, you might want to invest the 20 bucks or so on the yeast book. It has your answer, and better ways to store yeast for as long as you propose. Oil, glycerin, etc. Seriously it is an awesome book.

And to keep somewhat on topic to your question. I have used plenty or years-old yeast will no problem. Of course I stored it under STERILE liquid for that long. Re-starting doesn't sound like a sound plan. All you have to do is make up a starter or two when you are ready to use them. Same as what you propose minus the insane amount of starters to use.

suprchunk said:

With a name like that you should be telling us how to do it, not asking.

I don't know how slanting could be any more time intensive than you re-starting yeast for years. What if at the end of the year or years the yeast is bad? You just wasted years on this. Instead of the hour or so for the slanting.

And if you want to do this on the cheap, you might want to invest the 20 bucks or so on the yeast book. It has your answer, and better ways to store yeast for as long as you propose. Oil, glycerin, etc. Seriously it is an awesome book.

And to keep somewhat on topic to your question. I have used plenty or years-old yeast will no problem. Of course I stored it under STERILE liquid for that long. Re-starting doesn't sound like a sound plan. All you have to do is make up a starter or two when you are ready to use them. Same as what you propose minus the insane amount of starters to use.

Click to expand...

Oh come on, it's just a screen name. I really just wanted to incite some discussion. I do need to pick up the Yeast book. That and Brewing Classic Styles are my next two purchases. I've just recently started understanding the crucial importance yeast plays in beer, so it's fun to learn more and be able to fully utilize it. Even with washing the yeast from my last batch, I feel like I'm back in my high school chemistry class doing fun experiments.