Author Topic: Re-using yeast  (Read 752 times)

Offline yso191

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Re-using yeast
« on: March 27, 2014, 02:21:51 PM »
I am just completing my 2nd brew using my new 7.3 gallon conical from Stout Tanks.  It is my first attempt at saving the yeast for a subsequent brew.  After determining that FG had been achieved, I dumped the yeast and was shocked at the amount.  This is Wyeast 1968 (London ESB). I started with one smack-pack with a 1 liter starter.  After fermenting 5.5 gallons of a 1.053 APA I got a lot more yeast than I expected.  Is this a normal amount of yeast?  If so, how much of it should I repitch for the next brew?  Here is the picture:

Steve
All Hands Brewing

Offline Joe Sr.

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Re: Re-using yeast
« Reply #1 on: March 27, 2014, 02:31:05 PM »
That looks about right.  I usually get about a liter.  Maybe less.
It's all in the reflexes. - Jack Burton

Offline yso191

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Re: Re-using yeast
« Reply #2 on: March 27, 2014, 02:42:45 PM »
That looks about right.  I usually get about a liter.  Maybe less.

Good.  Thanks.  I also just went to Mr. Malty and noticed they had a repitching function.
Steve
All Hands Brewing

Offline Joe Sr.

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Re: Re-using yeast
« Reply #3 on: March 27, 2014, 02:45:46 PM »
Misread, or read too quickly.

I wouldn't repitch the full volume.  I get about a liter of yeast from my batches.  If I was using it right away, I'd repitch about half.

If you use the full amount, your probably overpitching.
It's all in the reflexes. - Jack Burton

Offline yso191

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Re: Re-using yeast
« Reply #4 on: March 27, 2014, 02:47:18 PM »
But, Mr. Malty says I need 117 mL of slurry.  I've obviously got 7 times that.  Is there any easy way to get the right amount, or do you just guesstimate?
Steve
All Hands Brewing

Offline yso191

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Re: Re-using yeast
« Reply #5 on: March 27, 2014, 02:48:07 PM »
Sorry, posted just as you were.  That works.  About 1/2.  Thanks!
Steve
All Hands Brewing

Offline Joe Sr.

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Re: Re-using yeast
« Reply #6 on: March 27, 2014, 02:50:22 PM »
I guesstimate.  Short of counting cells you really don't know what you have.

Obviously it depends on your OG, too.  I'm typically repitching into big beers so I'll go with a big pitch.

Go with Mr. Malty if that's your comfort level.
It's all in the reflexes. - Jack Burton

Offline Joe Sr.

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Re: Re-using yeast
« Reply #7 on: March 27, 2014, 02:52:53 PM »
Sorry, posted just as you were.  That works.  About 1/2.  Thanks!

We're posting over each other.

My conference call is obviously boring.

You won't go wrong with 1/2, but if you want to try and be more accurate go with Mr. Malty.

It will work either way, especially with a fresh slurry.
It's all in the reflexes. - Jack Burton

Online kramerog

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Re: Re-using yeast
« Reply #8 on: March 27, 2014, 02:56:33 PM »
But, Mr. Malty says I need 117 mL of slurry.  I've obviously got 7 times that.  Is there any easy way to get the right amount, or do you just guesstimate?

I think Mr Malty also assumes a density to the repitched yeast, which you may not be at.  You have to look at My Malty's documentation about that.  When repitching yeast to a big beer, I use about half of the yeast  from the small beer.













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Offline ynotbrusum

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Re: Re-using yeast
« Reply #9 on: March 27, 2014, 03:05:34 PM »
1/3 repitch of fresh slurry for similar gravity ales; 1/2 for lagers.  A little more if less than really fresh or if a bigger beer for the repitch.  Nothing scientific, but it has served me well.  After a couple weeks or so, I would want to consider a starter from the slurry using a couple tablespoons of the slurry.
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Offline klickitat jim

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Re: Re-using yeast
« Reply #10 on: March 28, 2014, 01:48:10 AM »
I figure 1 bill per mill. But I rinse with sterile distilled. Five gallons of 1.050 ale gets 250 ml. Five gallons of 1.050 lager gets 375. This makes great beer for me, but I'm not suggesting it's the way to do it.

Offline reverseapachemaster

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Re: Re-using yeast
« Reply #11 on: March 28, 2014, 05:27:26 AM »
Is that everything that dumped from the cone or is that yeast rinsed out from the trub?
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Offline redzim

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Re: Re-using yeast
« Reply #12 on: March 28, 2014, 06:51:42 AM »
Is that everything that dumped from the cone or is that yeast rinsed out from the trub?

I stick a flask like that in the fridge, let it settle for a couple days, then pour off about 75% of the liquid that is on top of the compacted slurry. Then I "sloosh" that around (I think that's a technical brewing term, right?) to loosen the slurry, and measure whatever Mr Malty calc says for my beer's OG and the yeast's harvest date. It's worked great for a couple years. I think I may be over-pitching a hair, as some beers start fermenting in 4 or 6 hours after pitching, but it works for me.

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Re: Re-using yeast
« Reply #13 on: March 28, 2014, 07:51:31 AM »
But, Mr. Malty says I need 117 mL of slurry.  I've obviously got 7 times that.  Is there any easy way to get the right amount, or do you just guesstimate?

Serial dilution is pretty easy. Once you've done it once for a given strain and harvesting equipment/technique, you can go with that number and get fairly good precision.

http://www.homebrewing.com/articles/yeast-management.php
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Offline yso191

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Re: Re-using yeast
« Reply #14 on: March 28, 2014, 08:57:16 AM »
Is that everything that dumped from the cone or is that yeast rinsed out from the trub?

That is everything dumped from the cone - no rinsing.  How important is rinsing?  Here is a pic taken today:



Whenever I think of rinsing yeast I try to envision a method where it is not exposed to airborne contaminants, and I don't come up with anything.  I'm probably being too anal about it.  I just want to do it right - that's the bottom line.
Steve
All Hands Brewing