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Author Topic: Repitching yeast  (Read 1457 times)

Offline miker88

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Repitching yeast
« on: July 21, 2014, 07:52:21 pm »
I was going to try to repitch yeast for the first time. I brewed a pale ale at 4.5% abv and collected the yeast from the primary and put it in a  nalagen bottle under billed water on the frige. My questions are do I need to propagate it back up to repitch into another APA  or just do a quick starter to get it going. Also do I pitch everything that I collected or do I need to clean it up. And how do I do that exactly. I was under the impression that I swirl the yeast up and throw away what settles to the bottom after ten min?


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Re: Repitching yeast
« Reply #1 on: July 21, 2014, 08:59:35 pm »

Offline morticaixavier

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Re: Repitching yeast
« Reply #2 on: July 22, 2014, 08:34:38 am »
When did you harvest? how much yeast slurry? what is the gravity of the target wort?

mrmalty.com is a good resource for estimating the amount of slurry to pitch into the next batch. You still have to take a WAG or two but it's not that complicated and as long as you are reasonably close it's all good.

Potentially it's as simple as collecting the slurry from the first batch and pitching it into the next. If you are doing a really big beer (1.100+) you might want the whole cake but generally for ales you want about 1/3 of the cake and about 1/2 for lagers.

It's going to take off quickly especially if you don't chill your wort down to ~5 degrees below your target fermentation temperature so be prepared with a blow off rig.

as S.cervevisiae points out in his referenced thread, the boiled water thing is not ideal and the rinsing is not necessary. But you can still use what you have.

If the yeast has been in your fridge for several weeks or more I would just take a tablespoon full and make a new starter with it but even that's not absolute. it will be just fine to pitch ~200 ml of the slurry into your new wort even after 3-6 weeks.
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Offline Joe Sr.

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Re: Repitching yeast
« Reply #3 on: July 24, 2014, 10:46:26 pm »
I save and reuse my slurries all the time. I simply pour them into a sanitized bottle and store them in the fridge.

As mort says, make a starter if it's been awhile. Otherwise, you can just pitch what you have. 1/2 of the previous yeast cake is probably all you need.


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Offline mainebrewer

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Re: Repitching yeast
« Reply #4 on: July 25, 2014, 04:51:29 am »
I've been reusing yeast for the last 2-3 years.
I sanitize a mason jar, fill it with yeast from the carboy and put it in the fridge for the next batch.
I used to pour off the beer that would rise to the top of the mason jar and replace it with distilled water. Then shake the jar to mix the water into the yeast. My thought was to reduce the amount of alcohol in the solution.
However, recently I've learned that that is not necessary and likely harmfull for the yeast.
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