Reuse Yeast Left in Carboy

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

msmith92

Well-Known Member
Joined
Jan 10, 2012
Messages
272
Reaction score
2
Location
dayton
So, I've seen that people will rack their finished beer out of a carboy and then pour their wort on top of the remainder.

My question is..what about all that trub? Doesn't that affect the beer or is it ok?
 
I think it probably depends on the beer. If the 2 beers are similar enough it might not matter. You probably don't want to pitch a witbier on the yeast cake from a double IPA (although you probably wouldn't do that anyway because it would be the wrong yeast, but you get the idea).

I usually wash the yeast and then use it to make a starter. Washing gets rid of most of the trub.

https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/
 
As mentioned it really depends on what the initial beer was and what you then want to make and how similar the profiles are. If there is a big difference in the two beers the yeast should be washed so the remaining trub does not have influence on the second brew.
 
Also, keep in mind that dumping on the cake will probably be grossly over pitching unless it's a pretty high gravity brew. Use Mr. Malty to determine how much you need to use when re-pitching from slurry.
 
Seems like there is a lot of success with this method though. Has to be worth while.
 
It does work, no arguing that. The result will be beer. The question is, how good do you want your beer to be? Saving yeast from the fermenter and repitching it is a very successful practice, but deviating from proper pitching rates is whole different story.
 
It works fine. I've done A/B brews with fresh yeast vs gelled, unwashed, 2nd generation yeast cake and there is very little difference in taste.
 
I had this same thought a while back so asked. I asked a local brewmaster about this cause he also owns a homebrew shop, he said you can, but would be better trying to poor the yeast layer on top of already aerated beer.
 
It does work, no arguing that. The result will be beer. The question is, how good do you want your beer to be? Saving yeast from the fermenter and repitching it is a very successful practice, but deviating from proper pitching rates is whole different story.

Exactly ! A+
 
Honestly, I think the best answer is try it, and let us know how it turns out.

People seem to dismiss negative effects from the trub when I talk to them or read the forums. I think the books make more out of it than people have experienced in practice. Supposedly, if it breaks down, it may impart a soapy flavor in the beer. But folks on here seem to typically leave their beers in primary for 3-4 weeks. I've even seen people leaving their beers in primary for 6-8 weeks. And they generally like the resulting beer! That should help lift some concern about trub (although if you left your original beer in primary for those 6-8 weeks, I might proceed a little more cautiously.)

As others have pointed out, you are starting your beer out with way more yeast than you need when you brew on top of a yeast cake. Remember how little yeast your original beer started out with? The yeast cake is many times larger in cell count, and now you are starting a beer with all of that yeast.

I think the primary concern with over pitching is too little yeast characteristics being imparted in the beer. Ester and phenol production is correlated with yeast cell reproduction. Your yeast won't need to reproduce nearly as much since there is already enough of them to ferment your beer when you are fermenting on top of a yeast cake. Depending on the style, you may not care about ester and phenol production. If there are other concerns with over pitching, I'm sure others can chime in.

Is it worth it? I think so. You'll still get the satisfaction of reusing your yeast, improving your overall brewing knowledge and experience. You should already have all the equipment you need, as opposed to yeast washing where you may need to collect some jars and some equipment to make a yeast starter, if you don't already have that.

I just started washing yeast. I haven't yet brewed on top of a yeast cake. I'd like to try it eventually. I'm all for experimenting and having fun. Even if a technique is considered inferior to another, wouldn't it still be fun to try it out and see what results? Try it out, don't worry, relax, have a home brew. (And then be sure to let us know how it turned out!)
 
No problems doing that here. Lots of brewers have strong opinions against doing things like this with no experience actually doing it themselves. I routinely brew a small to medium beer - 1.045-60 and rack an imperial strength beer on the yeast cake - troub dry hops and all.

Just make sure you have a blow off assembly...and it's not a bad idea to rack this beer to a secondary for dry hopping. - though most of the time I don't bother.

YMMV and IMHO and WTF
Steve da sleeve
 
well if its too much yeast being the problem.. can't one just scoop some trub out? how much? who knows. but it would be less now :)
 
I'm curious if you decided to dump your new batch of wort on the yeast cake of your previous batch. I'm thinking of doing the same thing for the first time. I am currently fermenting a kolsch using WLP029 and want to use the yeast cake for a Octoberfest.
 
i reuse the yeast cake all the time. i'll do a cream ale with us-05, then do an ipa. i'll cook up a bitter, then drop a barleywine on top of it. theme here? it's ok, just drop a much stronger beer on top of it
 
Hay guys, I want to reuse my yeast. Fermentation is finished but my mash is cloudy and no yeast cake at the bottom of my Carboy leads me to believe that the yeast is still in suspension. How long should I wait to collect it. Is it ok for me to cold crash my mash, or will that risk killing the yeast? I have (2) 5 gal carboys at 15% so I can manage to put one in the fridge at a time for a few hours while the wife is at work! Haha.
 
streetmachine said:
Hay guys, I want to reuse my yeast. Fermentation is finished but my mash is cloudy and no yeast cake at the bottom of my Carboy leads me to believe that the yeast is still in suspension. How long should I wait to collect it. Is it ok for me to cold crash my mash, or will that risk killing the yeast? I have (2) 5 gal carboys at 15% so I can manage to put one in the fridge at a time for a few hours while the wife is at work! Haha.

Is your fermentation done? Check your gravity. Yeast will pretty much always be in suspension. Cold crashing helps. I'm sure there's a yeast cake in there somewhere.
 
Back
Top