Yeast Cake / reusing yeast

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FreshZ

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What are the advantages to reusing yeast from a previous batch? I have heard this few times on this board and I'm not sure how it works or why you would do it? To save the few bucks new yeast costs? How do you do it?
 

pwndabear

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$$$$!!!

You also have an active yeast that just finished another beer and is fully acclimated to the job at hand: beer.

There are a number of ways you can do it: some people wash the yeast, some will syphone it out and just put it in a new batch, some will simply rack their new beer onto the old yeast cake (the 3rd being the easiest of them all).
 

Shaneoco1981

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There are a few ways. You can wash the yeast, or just keep the carboy with a sanitized air lock on it if you are going to be brewing in the next 2 or 3 days and just put the wort right on the yeast cake. There is one major problem with reusing the yeast cake is that there is everything else along with yeast in there. Hop particles, dead yeast, proteins from krausen, etc. Washing yeast is really the way to go. It's not very hard at all. Google it, and there are a bunch of web pages with videos on how to do.
 

eppo

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Yes, you can do this, from what I've heard, in subsequent generation of the yeast, the beer will come out better than with the first generation.
The best way of doing it (to my knowledge) is to wash the yeast. Basically you take yeast from your cake and you separate the yeast from the trub.
Definitely do some reading on this if you would like to try it. You should use this yeast within a week of washing it.
DO NOT just pour new wort on an existing cake. In that cake you have trub, dead yeast, that can result in off flavors from your beer.
I did wash yeast a while back. My second generation worked out well, the next one did not (i'm sure it had something to do with my process). If i brewed enough i'm sure i would try it again.
 

pwndabear

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imo, if you decide to just rack onto your old yeast cake, for small homebrews, i really wouldnt worry about it. there are indeed things left over from the previous batch but yeast has a life cycle and will eat dead yeast cells and clean up after itself. everything from the previous batch will fall out of suspension and you will be fine.
 
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FreshZ

FreshZ

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So, in order to just pour my wort onto the old yeast cake, I need to brew within a few days? Also, I guess I wouldn't clean or sanitize the primary?

Don't yeast get used up eventually? How many batches can you make using the same yeast?
 

bk0

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If you did this a ton of times in a row I guess the primary would get kind of gunked up because it would never get cleaned. Other than that I don't think there would be any ill effects.

I love reusing yeast cakes. It's simple and easy and you don't have to worry about making starters.
 

eppo

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Yes, i would use the yeast within a few days, up to a week. Also, dont just dump your new wort on top of the old. Regardless of the factors i said above, There is way too much yeast there. Just use some of it. too much yeast can be bad too, you may lose character in the beer that you normally look for.
Take a look at the calculator on www.mrmalty.com there is a calculator there for using a Slurry also. that should help you out.
 

amandabab

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If you did this a ton of times in a row I guess the primary would get kind of gunked up because it would never get cleaned. Other than that I don't think there would be any ill effects.

I love reusing yeast cakes. It's simple and easy and you don't have to worry about making starters.
I only do 2 ferments then clean the primary. I also do the next batch boil the same day I rack to my secondary.
even only pitching on the cake once, then starting with new, yeast budget is down 50% without any added work or off flavors because I secondary.

yeast used to be stupid cheap, now its expensive enough to be worth tracking.
 

h22lude

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Just as others have said, rinsing yeast will save you a little money and the yeast will be ready to start fermenting another batch.

You do want to make sure you match the yeast with another similar beer. You don't want to use a hefe yeast with a blonde ale or a big beer yeast with a low gravity beer...unless that is what you are going for.
 
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