Author Topic: Harvest this yeast cake for reuse or no?  (Read 2021 times)

Offline brewsumore

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Harvest this yeast cake for reuse or no?
« on: September 08, 2017, 09:51:53 PM »
I've read it's not recommended to harvest and store for later re-use, a yeast cake from the bottom of a fermenter if any fruit or spice was used.  I'm curious if there are degrees of grey here.

Tomorrow I will begin to cold crash two 5-gallon buckets of saison (OG 1.055) and then rack the beer into kegs a couple days later.  The remaining two yeast cakes will undoubtedly have a tiny amount of non-yeast particulate that is not from malt. 

That is, for an 11-gal yield of wort runoff from the kettle (after leaving behind a gallon of hop/break/spice/peel spooge in the kettle), I had added with at least 5 minutes remaining in the boil 1.3 oz of lightly ground coriander, an ounce of dried bitter orange, a small amount of fine zest from a couple fresh sweet oranges, and 2 grams cracked grains of paradise.  And when I ran off the wort from the kettle into the fermenters, all was first strained through a fine-mesh strainer.

I'm pretty much looking for three basic options for a response, as follows:

1) in my experience, or from reading articles and/or other forum threads it's not worth the risk,

2) I've done the same thing a time or two with no problem or read, or know from industry practice that it's not very risky,

3) I've done this plenty of times with no problem.


Thanks!



« Last Edit: September 08, 2017, 10:05:21 PM by brewsumore »

Offline flars

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Re: Harvest this yeast cake for reuse or no?
« Reply #1 on: September 08, 2017, 11:23:15 PM »
The yeast you harvest will hold little of the flavor from your previous beer.  The left over beer poured from the fermentor with the yeast will have some aroma but you will be decanting the left over beer before pitching into a new wort or pitching into a starter wort.  I don't think there is any risk if you decant the spent beer before pitching.

You could also decant the previous beer, after the yeast compacts in your collection jar, and replace it with a Lite beer someone left at your place.  Your nose will then tell you if the yeast has any left over flavors.

Offline brewsumore

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Re: Harvest this yeast cake for reuse or no?
« Reply #2 on: September 08, 2017, 11:42:15 PM »
Thanks Flars.  I guess where I was going with this is I don't know if the veg material in the stored yeast would potentially pick up bacteria, or otherwise contribute to off flavors in its next use, or subsequent generations. 

It does make sense that having been boiled, the veg matter became completely sterilized along with any trub that went into the fermenters before commercially purchased yeast was pitched, and so bacterial risk of any harvested would be equivalent to that of the yeast itself.

As you suggest, either decanting the top-off beer in the canning jar, before re-pitching, or better yet adding some leftover bottled light beer would further reduce any flavor impacts from the spice/veg component.

Seems pretty low risk to me too!   :)

Offline Slowbrew

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Re: Harvest this yeast cake for reuse or no?
« Reply #3 on: September 09, 2017, 05:22:32 AM »
My understanding of the recommendation to not reuse yeast from beer with fruit in it is more about recipes with some number of pounds of fruit.  I wouldn't worry about it in your case.

Paul
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Offline reverseapachemaster

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Re: Harvest this yeast cake for reuse or no?
« Reply #4 on: September 09, 2017, 08:34:47 AM »
For the volume you used I would not be worried about carryover. I've reused several times after adding spices.

Hops are technically a spice and most people have no problem reusing yeast after adding hops to the boil/after boil/dry hop and use way more hops than you have other spices.
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Re: Harvest this yeast cake for reuse or no?
« Reply #5 on: September 09, 2017, 08:40:25 AM »
As the previous 2 posts said, not a problem at all.
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Offline brewsumore

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Re: Harvest this yeast cake for reuse or no?
« Reply #6 on: September 09, 2017, 10:49:15 AM »
Excellent!  Thanks all.  Once again, RDWHAHB!

Offline brewsumore

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Re: Harvest this yeast cake for reuse or no?
« Reply #7 on: September 24, 2017, 11:44:32 AM »
My understanding of the recommendation to not reuse yeast from beer with fruit in it is more about recipes with some number of pounds of fruit.  I wouldn't worry about it in your case.

Paul

Hi Paul, I meant to get back to you after finding the researched online article I had read before posting - yeah I know a lot of online articles are suspect and often downright incorrect.  Anyway, I haven't located that article but it definitely had indicated the preference for not re-pitching yeast in any batch that used "fruit, peel, and/or spices".  It was wrong. 

BTW, my kettle soured plum saison which is the re-pitch batch is progressing very well and continuing to drop SG during the fruit added stage (plum puree) and the hydro sample yesterday the 3rd day on fruit, and continued actively fermenting at 1.010, tasted really good.  This should be a good beer.  Of course, as the yeast cake this time is mixed with fruit puree I will toss it after I cold crash and rack to kegs.

Adding the puree at 80F after primary ferment of the kettle soured straight wort was mostly done sure kicked up instant massive blow off so I added a few drops of anti-foam drops to knock it back some.

 :D
« Last Edit: September 24, 2017, 12:32:47 PM by brewsumore »