How many yeast re-uses?

So I just started all-grain. WOW... what a leap. Now I am thinking ahead for a yeast reclaim. I have done this in the past but my most recent one was a very slow start. I have a multi-part question:

1. I have read that one should only reclaim a few times. But why is this the case? When yeast breeds and multiplies, isn't new healthy yeast created? At the end, isn't that amount generally the same for each batch?

2. I was thinking about pouring off roughly 30 oz or so of wort in its own container that I would insta-cool to room temp and start my yeast in that... then once the rest of the wort comes down, just blend it back. I have been told no on this too, but no one can give a good reason. The yeast will start multiplying sooner, so more will hit the big bucket once it cools. Can someone tell me why I shouldn't do this?

I don't re-use... I throw that nasty stuff away.
What I do is propagate fresh yeast by doing stepped up starters to grow a large volume of yeast that I can split into many batches. I buy once, and use many many times.

I read that it was 5-6 re-uses but not too sure why it's not more or less.

You can reuse, but not indefinitely. The reason is the environment which yeast makes beer is far more intense than yeast natural environment where it will find small areas of sugar to consume. In brewing you push the yeast in a way that encourages it to do what you need, not what is healthiest for the yeast. In time this stresses the yeast and only those with mutations allowing them to keep going will survive. You can't know what those new predominant yeast might do.

"You can't know what those new predominant yeast might do."

Sounds like an experiment in the works!

wickman6 said:

"You can't know what those new predominant yeast might do."

Sounds like an experiment in the works!

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Actually, I had heard this somewhere as well... and the experiment reply is a good one. Why wouldn't I want to propagate a yeast that has adapted to survive my environment? Seems like the perfect / right thing to do.

I recently started doing this with wlp090 and im up to 5 reuses with no problems at all, im going to keep using it until or if I have issues

I usually just pitch on top of an existing yeast cake once then save half of it and use it one more time then throw it away.
2 bucks a batch for yeast works for me.

Many times, I’ve reused yeast by making starters from primary slurry for 10-20 generations. I couldn’t tell any difference compared to new.

Of course it’s risky, but it’s certainly possible.

My Bell's yeast goes about 4 or 5 times, then re harvest. I've found the attenuation seems to suffer a bit after 4 uses.

Breweries usually throw out yeast after 3-5 normally. I've heard after 7 it goes bad but it's case by case.

https://www.homebrewtalk.com/entries/yeast-harvesting-novel-approach.html


Works great and it's freshly harvested directly from the starter every time!

A good read...right from white labs......http://www.whitelabs.com/beer/craft_yeast_storage.html

On the bottom of this article is says between 5-10 generations. One idea is to preserve some by freezing with glycerol, and makeing starters from that. This IIRC is the way that breweries like Heineken have managed to use the same strain since the 1800's thousands of generations later.

Get some unformed two liter bottles (like Whitelabs vials), make an oversized starter, and then store a few tubes of yeast from the starte in a glycerine solution in the freezer.

I think I buy yeast one or two times a year, usually when some special release I want to try has come out. Every other time I pull a vial from the freezer, make a starter, make a couple more tubes of useable yeast while making sure you've got enough to pitch, and then pitch the remaining volume.

IMO, though, this works better if you've got a stir plate. Yeast seems healthier with a stir plate so it lasts a bit more heartily during freezing.

I typically use washed yeast about 4 or 5 times, then that's it. It helps bring the cost way down that's for sure. Besides, I cant bring myself to just flush them down the drain every time, I feel bad for them after all the hard work they did for me and my beer!

So even if you use the 5-10 generations rule you can get hundreds of batches from one batch of yeast. When I harvest I freeze in glycerol. I use one vial of my second generation yeast. Then when I harvest that yeast I freeze 5 vials from that. That way I can save all my other 2nd generation vials for later use.

For a while, I was spending a lot of time saving yeast, different strains, building them up, reusing, etc. Now, I am much less work-intensive on how I use yeast. Basically, its about planning my brewing schedule - for example, three weeks ago or so I brewed a mid-strength APA (1.052ish) using WLP028 (Edinburgh) from a starter I made. When I racked into a secondary for dry hopping, I saved the yeast in sanitized Ball jar and popped it in the fridge. This Sunday, I am brewing a bigger (1.072ish) IPA and will pitch that saved yeast into it.

I currently have a Belgian Golden Strong in the fermenter and will save that yeast to repitch onto a Quad that I am planning on brewing about three weeks from now.

More planning, but less actual work, for my setup and brewing habits, at least.

edufur said:

Actually, I had heard this somewhere as well... and the experiment reply is a good one. Why wouldn't I want to propagate a yeast that has adapted to survive my environment? Seems like the perfect / right thing to do.

Click to expand...

This seems logical but the things we look for from yeast--attenuation, flocculation, esters, etc.--result from controlled stresses manipulated by the brewer. If you get a majority of yeast that are not stressed by the wort environment then these benefits are affected or even lost. Also, if the yeast has been weakened by reuse you can get results that are common for weak yeast--like high diacetyl or fusel alcohol that are common for underpitching--undoing the best benefits of repitching.