Re-using yeast

[Normalicous]

Sorry for the noob question but I am new to home brewing and on my 5th extract batch. I have some harvested yeast and want to know if I should save it and what type of beer I should use it with. It started out as liquid wyeast (american ale) and I fermented it with an american pale ale. I then used most of that yeast cake and fermented it with a brown ale (carribou slobber from northern brewer.) Now I have I savedit again and am wondering if it should still be good for a third batch and what type of beer to use it for. Thanks!

 

[kanzimonson]

There is a sticky at the top of the fermentation and yeast page titled "Yeast Washing Illustrated." Read that.

Then read this: http://www.mrmalty.com/pitching.php

Then play with this: http://www.mrmalty.com/calc/calc.html

Then listen to the Brewing Network's Brewstrong episodes titled "Repitching Yeast," "Yeast Washing," and "Yeast Starters."

After you do all these things, you'll know how to optimally reuse yeast from batch to batch. Until then, for the love of satan don't repitch onto an entire yeast cake. If you want some basic guidelines I suggest this:

-use your yeast as soon as you can without disrupting the batch it's currently fermenting
-use about 6-8oz of yeast slurry in an average strength beer
-use more for bigger beers.
-be sanitary

Care for your yeast, IMO, is the most important thing in brewing, so it's totally worth it to take some time and learn all this stuff. Have fun!

 

[breez7]

If you have been perfectly sanatary and the yeast is clean, it should be good for a couple of weeks in the fridge. As for what to use it on, thats your decision, I'm guessing it was Wyeast 1056 which you could make thousands of different types of beers with. Make what you like you to drink.

 

[Malticulous]

With proper pitching rates the color of the original beer has very little impact on the beer it's pitched into. With fresh yeast you only need about 1/2 cup of slurry. 1/2 cup into five gallons isn't going to change the color noticeably unless your really trying to make zero SRM beer.

I think yeast rinsing is more hassle than it's worth and leaving it with some beer is better due to alcohol and low pH minimizing growth of contaminants.

 

[Normalicous]

Thanks for the info, I am reading those links now. I guess I wanted to know if I needed to wash the yeast after a pale and brown ale, or if it was tainted in any sort of way from that type of beer before re-pitching. I think the info in those links should help me out.

 

[ddockery]

I seem to remember reading (although I can't find it now) that when reusing yeast, it should only be used for beer with the same or higher OG. Any truth to this?

 

[kanzimonson]

That's often repeated but really, so long as the harvested yeast came from a low IBU, low gravity batch, and experienced a healthy fermentation with plenty of nutrients, then it's optimal for fermenting any beer next.

If any of these factors was less than optimal, then you're pitching less than optimal yeast in your next batch. I'm sure it will "work" but how good will it be? Some people are willing to accept less than perfect. You just have to decide where you draw your own line.

 

[TANSTAAFB]

I seem to remember reading (although I can't find it now) that when reusing yeast, it should only be used for beer with the same or higher OG. Any truth to this?

You should start w/ a lower gravity beer that is not excessively hoppy. You can then wash and save multiple jars of this yeast from that batch to pitch into starters and brew multiple different beers, small, big, or in between.

OP, if you are reusing the yeast after each brew, then you are changing the yeast with ech generation due to mutations and selection pressures of your beer's different environments. You can re-use a yeast for several (5-6) generations (the number has been argued ad nauseum) but then it has changed significantly and you should start w/ fresh yeast.

Let's say the original fermentation is 2nd generation (pale ale), the smack pack or vial being 1st gen. You reuse that for a brown ale (3rd generation). You pitch a big stout onto it (4th generation). By now, you have progressed through increasingly higher ABV beers and should not pitch a pale onto the cake from the big Imperial Stout. You move from smallest and lightest to biggest and darkest with this method.

However, if you wash into several jars, you can brew whatever you want as you are not saving the yeast after each brew. I washed 1 smack of 1056 into 6 jars and brewed 6 different beers, all of which are brewed with 2nd generation yeast. If one of those is a small, low hopped beer like a Cream Ale and I wash that into 6 jars, I can brew six more beers with this 3rd generation yeast.

Hope that helps clear things up

 

[ddockery]

Thanks, that helps. I have a yeast in a Black IPA I plan on bottling this week, and will be re-using that for another IPA. How do the IBUs affect the yeast? It sounds like I shouldn't take this back to something less hoppy, like a red ale.

 

[kanzimonson]

The "experts" would say you shouldn't reuse that yeast.

You know how we say hops add a preservative quality to the beer? It's the IBUs. The isomerized acids coat microorganisms (including yeast) and inhibit their growth.

Once again, I'm sure it will "work" but do you just want to make beer or do you want to make the best beer possible?

 

[TANSTAAFB]

Thanks, that helps. I have a yeast in a Black IPA I plan on bottling this week, and will be re-using that for another IPA. How do the IBUs affect the yeast? It sounds like I shouldn't take this back to something less hoppy, like a red ale.

I'm certainly no expert so I hope one chimes in here, but I believe it has to do with selection pressures on the yeast and the hop resins/ oils coat the yeast cells as well as the possibility of introducing flavors into subseqent brews. You are not saving pure yeast slurry when washing or pitching onto a cake so you will get some trub from the brew. This can change color and flavor. So, pitching a pale IPA onto yeast from a Cascadian Dark Ale D) can have affect the color and flavor of the IPA.

Brew a Pale Ale, wash it, and then brew CDAs and IPAs and IIPAs and RISs to your hearts content :rockin:

That said, you will still have yeast, just maybe not the SAME yeast you put in. For example, by harvesting a batch of 1056 from the secondary rather than the primary, I selected for yeast cells that are highly attenuative but very poorly flocculating. All the resulting brews were very clean (like normal 1056) but were VERY dry and took longer than normal to clear. A jar of this washed yeast would take weeks to settle completely to the bottom while the WLP550 I just washed cleared and settled in a day!

 

[kanzimonson]

I mostly agree with what TANSTAAFB wrote, though it needs to be clarified that the problem is not really with the trub. The problem is the hop resins that are directly coating the yeast. It's not easy to wash that stuff off (think of how much effort it takes to scrub hop resins off your tongue). I wouldn't reuse it.

My strategy is to time my brewing so that every 5 brews or so I'm making another average strength, average IBU wort. Then I'll save like 3-5 jars of extra yeast from this batch for use in bigger beers.

 

[TANSTAAFB]

I mostly agree with what TANSTAAFB wrote, though it needs to be clarified that the problem is not really with the trub. The problem is the hop resins that are directly coating the yeast. It's not easy to wash that stuff off (think of how much effort it takes to scrub hop resins off your tongue). I wouldn't reuse it.

My strategy is to time my brewing so that every 5 brews or so I'm making another average strength, average IBU wort. Then I'll save like 3-5 jars of extra yeast from this batch for use in bigger beers.

Thank you for the clarification kanzi. I do the same thing whan planning my brewing schedule. For example, I wash my 1056 from a 1043 14 IBU Cream ale recipe then brew anything I want. I just started a Belgian project where I am collecting multiple recipes to brew with different yeast strains. The first of each strain will be Saccharomyces' 1060 (or lower) 24 IBU Belgian Pale Ale recipe (it was one of the lowest gravity Belgian recipes I could find and I don't mind selecting for higher alcohol when brewing Belgians). I just bottled this recipe brewed with 550, brewed a Golden Strong with 150ml of slurry from it, and washed the rest for subsequent dubbels, tripels, dark strongs, etc.

 

[kanzimonson]

Most of my Belgians are higher alcohol as well and not optimal for reusing yeast so here's what I do: If the pitch rate calculator says I need a 1.5L starter, I'll make a 2L. As it winds down (but the yeast is still suspended in the starter), I'll pour 500mL into its own container and then pitch the other 1.5L.

Then I'll either store the 500mL or build it up again and then store it. Give it a try!

 

[TANSTAAFB]

Most of my Belgians are higher alcohol as well and not optimal for reusing yeast so here's what I do: If the pitch rate calculator says I need a 1.5L starter, I'll make a 2L. As it winds down (but the yeast is still suspended in the starter), I'll pour 500mL into its own container and then pitch the other 1.5L.

Then I'll either store the 500mL or build it up again and then store it. Give it a try!

Good idea, I will!!!

I have washed starters before, you just have a ton of yeast in a cake I hate washing down the drain!!! And when harvesting from starters you have to build ANOTHER starter or three to get the same yeast count. 1060 isn't that bad when most other recipes are 20 points higher, but I will probably scale it down to 1050ish for subsequent strains.

 

[ddockery]

I'm certainly no expert so I hope one chimes in here, but I believe it has to do with selection pressures on the yeast and the hop resins/ oils coat the yeast cells as well as the possibility of introducing flavors into subseqent brews. You are not saving pure yeast slurry when washing or pitching onto a cake so you will get some trub from the brew. This can change color and flavor. So, pitching a pale IPA onto yeast from a Cascadian Dark Ale D) can have affect the color and flavor of the IPA.

Thanks, this is exactly the piece that I was missing/hadn't sunk in yet. The Black IPA yeast will be dumped, and I'll plan my next couple of brews to try to reuse the yeast, because it's something I'd like to know how to do.

 

[jjones17]

Most of my Belgians are higher alcohol as well and not optimal for reusing yeast so here's what I do: If the pitch rate calculator says I need a 1.5L starter, I'll make a 2L. As it winds down (but the yeast is still suspended in the starter), I'll pour 500mL into its own container and then pitch the other 1.5L.

Then I'll either store the 500mL or build it up again and then store it. Give it a try!

Hey man! This is a great idea

Thanks for sharing, I am getting tired of buying liquid yeasts