Author Topic: Repitch slurry or new starter  (Read 1931 times)

BrewDorg

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Repitch slurry or new starter
« on: January 10, 2017, 10:52:22 PM »
Just kegged a 1.063 IPA and have collected a yeast cake of WLP007. I poured off as much beer as I could and scooped the cake at the bottom into an erlenmeyer flask with a sanitised spoon. I then added 500ml of boiled then cooled water and shook it up. I've never done this before, so I'm not sure this was the right thing to do.

This weekend I brew a 1.100 Russian Imperial Stout, 12.5L batch and I plan to use WLP007. Should I use the yeast I just collected or should I just make a starter from a vial I harvested already from a starter?

It seems like a waste of plenty of good yeast that I left behind. The IPA had a modest dry hop of ~50g so it's not too dirty. What is the best way of going about pitching this yeast cake if that's the best thing to do? Just looking for some opinions and advice thanks!

DEMPSEY

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Re: Repitch slurry or new starter
« Reply #1 on: January 11, 2017, 12:06:34 AM »
Washed the yeast in 4 separate containers to help clean out the hops from the IPA. Brew your RIS then decant the wash from the top of each container  and pitch all the yeast leaving behind the dead gunk at the bottom  of each container. This yeast has already had one ferment which was like a big starter for your RIS. The second time around should have the yeast rearing to go.
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molc

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Re: Repitch slurry or new starter
« Reply #2 on: January 11, 2017, 08:41:24 AM »
I'd do it and not even wash. Normally I just pitch about 250ml into the next big brew, a calculator will give you the correct amount to use.
Fermenting: IPA, Lambic, Mead
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Bubbles

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Re: Repitch slurry or new starter
« Reply #3 on: January 11, 2017, 08:50:15 AM »
I just pitch a portion of the yeast slurry. I haven't had any adverse effects over the years that would make me consider the pallaver of washing yeast.

If you're doing an RIS I'd consider pitching the entire cake. Very difficult to overpitch a beer style like that. I wouldn't expect any carryover of hop flavour in an RIS either.

neoanto

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Re: Repitch slurry or new starter
« Reply #4 on: January 11, 2017, 10:46:28 AM »
Would pitching the entire cake not be a bit of overkill?
Seems a huge amount to be pitching!

Bubbles

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Re: Repitch slurry or new starter
« Reply #5 on: January 11, 2017, 10:54:42 AM »
Would pitching the entire cake not be a bit of overkill?
Seems a huge amount to be pitching!

It is in normal beers, but in an RIS (probably over 10%), I'd rather be overpitching than underpitching.

The biggest problem with overpitching is the loss of flavour development while the yeast is in a growth phase. But in an RIS (with lots of roast and malt flavours), I wouldn't consider a slight reduction in yeast flavours to be a massive issue.

But that's just what I do... ;)

DEMPSEY

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Re: Repitch slurry or new starter
« Reply #6 on: January 11, 2017, 10:55:47 AM »
Maybe a little but look what he is pitching in to, a 1.100 gravity batch even if it is only 12.5 liters
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BrewDorg

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Re: Repitch slurry or new starter
« Reply #7 on: January 11, 2017, 11:03:47 AM »
Great stuff, thanks for the advice. Does the slurry above look typical and did I collect it ok? It was extremely compacted so I found it difficult to scoop into the narrow opening of my flask. I hope it is still sanitary. Even if my batch is only 12.5L, should I pitch the lot? That would be about 500ml of slurry?

The RIS will be above 10% for sure. I based the recipe on 65% but I have a sneaking feeling I will go beyond that. So either way I will have stronger wort or a larger volume of wort and therefore a need for more yeast  :)

DEMPSEY

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Re: Repitch slurry or new starter
« Reply #8 on: January 11, 2017, 11:09:01 AM »
Learn to smell the yeast smell and use the smell test to see if its OK.
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DEMPSEY

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Re: Repitch slurry or new starter
« Reply #9 on: January 11, 2017, 11:10:46 AM »
Looks fine,fridge it to help it settle and when pitching,decant the top liquid and use the center portion.
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BrewDorg

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Re: Repitch slurry or new starter
« Reply #10 on: January 11, 2017, 11:19:36 AM »
I'm guessing it should smell similar to a healthy starter? I'll have a sniff  :D

Bubbles

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Re: Repitch slurry or new starter
« Reply #11 on: January 11, 2017, 11:29:01 AM »
Great stuff, thanks for the advice. Does the slurry above look typical and did I collect it ok? It was extremely compacted so I found it difficult to scoop into the narrow opening of my flask. I hope it is still sanitary. Even if my batch is only 12.5L, should I pitch the lot? That would be about 500ml of slurry?

That's a characteristic of a lot of English yeast strains. They settle like a hockey puck. :)

For a reduced volume, yes, I'd consider pitching a reduced volume of slurry, say 1/2 or 2/3. 500ml would be a lot alright.

BrewDorg

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Re: Repitch slurry or new starter
« Reply #12 on: January 14, 2017, 10:40:23 AM »
So the yeast now looks like this. Compacted down to around the 250ml mark on my flask. Guess I'll decant and pitch it all later today.


Leann ull

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Re: Repitch slurry or new starter
« Reply #13 on: January 14, 2017, 01:59:08 PM »
That's loads, pour off as much of the beer as you can leaving 100ml to keep it fluid on a good shake, makes it easier to pour rather than it just glooping in.
There would also be trub on the bottom but it looks clean enough, smell ok?

BrewDorg

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Re: Repitch slurry or new starter
« Reply #14 on: January 14, 2017, 02:12:39 PM »
Smells hoppy but no weird or bad smell from it. Haven't decanted yet, I'll sniff it then too