Reusing yeast

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Kerrden

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I have an amber ale I am fixin to keg. And the same day going to make a Wee Heavy. People talk about reusing yeast but I have never done this. After I transfer my amber to the keg, do I need to pour the yeast into a sanitized container and then pour back in the fermenter for the Wee heavy? Do I pour it in the bottom before I transfer the wort to the fermenter? Or should I oxygenate the wort first then pour the yeast in the fermenter? Or do you just transfer the wee heavy in the fermenter without cleaning? What about all the crap stuck to the walls? Normally this beer takes 2 pkgs of yeast. Will I still need 2 or will 1 be enough. Help!
 

Redpappy

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I have done a wheat beer back to back. I waited till my new wort was ready, then I transferred my ready to carb beer into my keg, I had a little bit beer left, so I swirls it around to get everything mixed up well, then I poured my new wort into it, and let everything do it’s thing.
 

TheBluePhantom

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I prefer to clean the gunk off the walls, it is dried out and nasty. When harvesting yeast you get a lot more yeast, some of the calculators will tell you how much. I usually use a quarter cup of thick slurry. Think of your last batch as a huge starter for the next batch. But realize starters shouldn't be too high a gravity, and dark and hoppy can carry over to the next batch....
 

HB2 HughBHomeBrew

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I have an amber ale I am fixin to keg. And the same day going to make a Wee Heavy. People talk about reusing yeast but I have never done this. After I transfer my amber to the keg, do I need to pour the yeast into a sanitized container and then pour back in the fermenter for the Wee heavy? Do I pour it in the bottom before I transfer the wort to the fermenter? Or should I oxygenate the wort first then pour the yeast in the fermenter? Or do you just transfer the wee heavy in the fermenter without cleaning? What about all the crap stuck to the walls? Normally this beer takes 2 pkgs of yeast. Will I still need 2 or will 1 be enough. Help!
Just put the new wort into the fermenter without cleaning. Don't worry about the crap on the walls. I would oxygenate next but probably not necessary with all the splashing that goes on. You don't need any pkgs of yeast - that's kind of the whole idea!
 

IslandLizard

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I'm with @TheBluePhantom, and scoop (or save) out some of that yeast/trub slurry from the fermenter. Clean and sanitize the fermenter well, before adding the fresh wort. Oxygenate and pitch the saved slurry.

How much slurry to repitch?
A typical average (1.050) batch of beer will multiply the # of pitched cells by 3-5 times.
There will be trub left in it too, so it's not all yeast.

So after transferring the beer:
  • Swirl the leftover yeast/trub slurry well to bring all the yeast into suspension. Some tends to stick to the bottom, make sure you suspend that too.
  • Either judge the volume and scoop out around a quarter of it for your repitch.
  • Or pour (most of it) out into large sanitized jar (e.g., 1/2 gallon pickle jar). Mix well before pouring about 1/4 out into your new batch.
You should use a yeast calculator to estimate how much yeast to pitch:
BrewUnited's Yeast Calculator
 

RM-MN

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I've just poured the new wort right onto the yeast/trub. It ferments fine but...you are in effect pitching about 4 times the necessary yeast. You won't have the lag time while the yeast propagates and any effect caused by the propagation won't be evident. You also need to be prepared for an explosive fermentation as there will be so much more yeast than necessary that there will be no lag time and lots of activity.

Probably the best way is to collect all the yeast, divide it equally (best you can) into 4 containers, store 3 of them in the refrigerator, and pitch just one into your new wort.
 

Toxxyc

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I pitch right on the yeast cake, IF the styles are compatible. I won't, for example, pitch a Blonde Ale wort on a Stout's yeast cake. I'll pitch a Stout on a Blonde Ale's yeast cake though, that'll be fine. Also consider hops and so on used, specially if you dry hopped without a hop bag.

Generally though I'll make my wort a few days in advance and seal in a no-chill cube. Then I can be sure it's ready immediately after the beer is racked or kegged off the yeast cake. I don't do this more than once though, as the yeast cake contains a lot of trub as well and it becomes too much if you keep pitching on it over and over.
 

hottpeper13

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I would pitch on the yeast cake and not 02 it. Also because of the overpitch, I wouldn't repitch it. I do this with my RIS, one of which was 1.134, finished at 1.024 and that was Notty, third repitch.
 

jrgtr42

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If you're doing relatively similar gravities, then use only a portion of the yeast from the last batch. The only time I'll use the whole thing is when brewing a massive beer next.
I did a pale ale, then used the cake for a barleywine at 1.100 or something SG. that big needs the extra yeast to get going.
 

bwible

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I pitch right on the yeast cake, IF the styles are compatible. I won't, for example, pitch a Blonde Ale wort on a Stout's yeast cake. I'll pitch a Stout on a Blonde Ale's yeast cake though, that'll be fine. Also consider hops and so on used, specially if you dry hopped without a hop bag.

Generally though I'll make my wort a few days in advance and seal in a no-chill cube. Then I can be sure it's ready immediately after the beer is racked or kegged off the yeast cake. I don't do this more than once though, as the yeast cake contains a lot of trub as well and it becomes too much if you keep pitching on it over and over.
Exactly. I plan my brews light to dark, weak to strong - the same way judges judge beer so I can re-use yeast and minimize the impact of a previous batch on the next batch.
 

odie

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You could kinda do both....

swirl up the yeast cake...pour into some small jars (to save for later)...hold back about 1/4-1/3 in the bucket...dump the new beer in...
 
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Kerrden

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what is the difference between the yeast cake and the trub? are they separatable? Or they one in the same?
 

Tobor_8thMan

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Please understand, in the perfect world, we're supposed to only pitch the white layer of yeast after it settles. Of course, no one does this method. What do we, most homebrewers do? Pitch the whole thing we saved from the prior batch.

In my experience, re-pitch up to 5 times.
 

odie

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what is the difference between the yeast cake and the trub? are they separatable? Or they one in the same?
trub is all the solids/sediment that made it into the fermenter. It slowly drops and collects on the bottom. The yeast cake is all the dormant yeast (once all the sugars have been converted to alcohol) that settles to the bottom once the fermentation is complete.

The "trub I think is typically darkermay have specks or hops and other particulate matter. The yeast layer should be fairly white/beige and rather clean looking. But it's a thin layer I think.

Typically I would say the bottom of the "cake" is mostly trub and the top layer is mostly yeast. Now separating them is the "trick" IMO.

Most try to leave much of the trub in the kettle so that the fermenter will have a less "trubby" yeast cake.
 

Toxxyc

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If you really want to split and get just yeast (would be awesome, TBH), a separatory funnel would be great. I've considered buying one actually, if you can accurately cut trub and yeast you should make up the cost very quickly. A single yeast can should be fine for 4 or 5 future brews, easily.
 

SrLobaugh

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I have an amber ale I am fixin to keg. And the same day going to make a Wee Heavy. People talk about reusing yeast but I have never done this. After I transfer my amber to the keg, do I need to pour the yeast into a sanitized container and then pour back in the fermenter for the Wee heavy? Do I pour it in the bottom before I transfer the wort to the fermenter? Or should I oxygenate the wort first then pour the yeast in the fermenter? Or do you just transfer the wee heavy in the fermenter without cleaning? What about all the crap stuck to the walls? Normally this beer takes 2 pkgs of yeast. Will I still need 2 or will 1 be enough. Help!
If pitching into the same vessel just pour the fresh wort on the existing yeast cake, cap and let it go.
 

Gusso

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If pitching into the same vessel just pour the fresh wort on the existing yeast cake, cap and let it go.
Did that 3x on a single pack of 34/70. Probably could have gone more but didn't want to push it. Just started a fresh one on 34/70. We'll see how it goes. At least one more...
 
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