# Using Yeast Slurry



## Hop Me (11/6/09)

Hello Everyone. I've been reading too many books, and the most recent of those are "How to Brew" and "Designing Great Beer." I've found that I might be pitching far too little yeast just using the little packets, and my IPA may be an example of that. It fermented out fairly well, I think 73%, but it was cloudy as hell. I know that might be as much TYPE of yeast strain as HOW MUCH. Anyway, I keep reading that using yeast slurry from a previous batch is a good way to get a good pitch rate. 

So... My question is this: The diarrhea looking stuff with the slightly more firm than pudding texture at the bottom is the slurry, right? I got everything sanitary, then drained off the last of the liquid. All that was left was the stuff I described above. If I got the right stuff, do I just pitch it on in with the next bacth, or do I have to start it or rehydrate it. Thanks! Dave


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## newguy (11/6/09)

I ferment in glass carboys and what I do is just pour the new batch onto the cake from the previous batch. I don't remove part of the cake either - the full cake gets used. I typically reuse my yeast 3x (initial pitch from starter, then another 2 batches after that). My fermentations that are pitched onto the cake aren't any more energetic/volcanic than the initial fermentation from a starter. The only gotcha is that you have to have 2 or 3 batches worked out ahead of time so that once one is done, the next is immediately brewed. The longest I ever let my yeast cake sit is about a week - no issues. If you want to store the cake for some time before you use it you'll need to store it under sterile water. Someone experienced with the procedure will have to chime in with the particulars.

The one thing that I do acknowledge is an issue is that I typically don't get a lot of fruity esters which is likely because I'm using too much yeast. I'm going to try to remedy the situation with my next few batches by pouring out roughly half of the cake before I pour the new batch in.


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## smollocks (11/6/09)

DaveW said:


> If I got the right stuff, do I just pitch it on in with the next bacth, or do I have to start it or rehydrate it. Thanks! Dave


If your next brew is ready to go, just add about 100mL of slurry for a 23L batch. If you won't be pitching the slurry straight away, I would store it in jars or bottles under sterilised water in the fridge. You won't need a starter if you use it within 1 or 2 weeks, but after that I think it's recommended that you check the viability of the slurry by making a starter before pitching.


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## mwd (11/6/09)

smollocks said:


> If your next brew is ready to go, just add about 100mL of slurry for a 23L batch. If you won't be pitching the slurry straight away, I would store it in jars or bottles under sterilised water in the fridge. You won't need a starter if you use it within 1 or 2 weeks, but after that I think it's recommended that you check the viability of the slurry by making a starter before pitching.



+1 on that I have stored slurry for a few months in the fridge with no problems just gave the jar time to warm up quick slosh to get the yeast up into suspension and into the cooled wort in the FV.


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## geoffi (11/6/09)

A week ago I reused about 250ml of 34/70 slurry that had been in the fridge for one month. No starter, just allowed it to warm up a little then straight into the wort. It was fermenting strongly at 12c within 24 hours.


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## raven19 (11/6/09)

Tropical_Brews said:


> +1 on that I have stored slurry for a few months in the fridge with no problems just gave the jar time to warm up quick slosh to get the yeast up into suspension and into the cooled wort in the FV.



+2.

I have used one tablespoon of US-05 trub from one yeast cake into a fresh 22L batch with good fermentation within 12 hours.

I tend to use around half a cup now of yeast cake in repitched beers.

I tend to use a clean fermentor though.


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## christmasbender (11/6/09)

hi

i've got a couple of yeast slurrys sitting in bottles in my fridge (one about 2 weeks old and one about 4 weeks). they both still have some beer sitting on top of them. above it is mentioned to store under sterile water. will my yeasts be bad now for storing under the beer they came from or can i swap the beer for sterile water and be ok? planning on pitching the 4 week old slurry this weekend and the other in a couple of weeks.

cheers

christmasbender


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## newguy (11/6/09)

christmasbender said:


> i've got a couple of yeast slurrys sitting in bottles in my fridge (one about 2 weeks old and one about 4 weeks). they both still have some beer sitting on top of them. above it is mentioned to store under sterile water. will my yeasts be bad now for storing under the beer they came from or can i swap the beer for sterile water and be ok? planning on pitching the 4 week old slurry this weekend and the other in a couple of weeks.



Don't worry about it. I used to store yeast under beer just like you are doing now and I never noticed them being slow/sluggish/inhibited in any way. Since then I've read that storing yeast in water is preferable but I don't know why. If you swap the beer for water you're adding a possible spoilage/infection risk so just leave them as is.


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## Neill (11/6/09)

Here's what i do:

take your beer off the trub/yeast cake as much as possible
put in 500ml of tap water, swirl it all around so that the yeast cake is like a liquid slurry
pour it off into sanitised stubbies, usually you'll get about three of them out of a yeast cake
cap the stubbies (helps if they're screw top, for the reason below)
put them in the fridge, uncap them to relieve any pressure once a day for a few days
store as long as you need

when reusing, just pour the beer off the top, then let them warm to room temp for a few hours
put a bit of water in them, swirl it all up so it's liquid then pitch into a 1L starter to get it going, usually takes about an hour before it's going for gold
pitch it all in once the temperatures approximately match


I'm probably overpitching using half a stubby for a batch, but i'd much rather overpitch than underpitch :beer:


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## christmasbender (11/6/09)

thanks guys - always a little bit worried about yeasty matters plus i'm pretty new to the whole re-pitching thing but you've put my mind to rest now

cheers

christmasbender


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## geoffi (11/6/09)

To get an idea of how robust yeast really is, think about that fact that you can take that tiny layer of yeast from a stubby of Cooper's Sparkling, give it a couple of feeds and within a few days you can have a yeast starter that'll rip through your wort before you can say 'attenuate'.


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## hazard (11/6/09)

Neill said:


> Here's what i do:
> ... put in 500ml of tap water, ...


Tap water OK? You don't bother boiling this or taking any steps to sterilise it?


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## benno1973 (11/6/09)

Neill said:


> take your beer off the trub/yeast cake as much as possible
> put in 500ml of tap water, swirl it all around so that the yeast cake is like a liquid slurry
> pour it off into sanitised stubbies, usually you'll get about three of them out of a yeast cake
> cap the stubbies (helps if they're screw top, for the reason below)
> ...



Only change I'd make would be to boil and cool the tap water.

Edit: Beaten to it by hazard...


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## Neill (11/6/09)

errrr....my whole fermenter is full of tap water, so a bit in the yeast slurry is going to mean nothing.


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## geoffi (11/6/09)

hazard said:


> Tap water OK? You don't bother boiling this or taking any steps to sterilise it?



If you have town water, it should be pretty safe. (I only have a rainwater tank, so no untreated water gets anywhere near my brews.) I'd still give it a boil just to make sure, but you'd probably get a way with it, just as using tap water to dilute your brews should be fine.


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## benno1973 (11/6/09)

Neill said:


> errrr....my whole fermenter is full of tap water, so a bit in the yeast slurry is going to mean nothing.



True, but lots of people boil and cool their tapwater before adding to the fermenter. But you're right - the tradeoff (time and effort vs. result) is probably questionable.


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## Hop Me (11/6/09)

Whoa! Just posted last night and now I have all this awesome, distilled knowlegde. Thanksm guys! I'll take it all in and try it out. I'm quite excited to not be spending between 5 and 15 dollars extra per batch, AND... It seems like a lot of fun to experiment with it. Cheers, Dave.


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## Mantis (11/6/09)

I used tank water without boiling it and had no problems when doing kits and partials. Depends on your situation re: roof condition , overhanging trees etc etc. 
Used town water once and the brew ended up on the lemon tree :icon_vomit:


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## SJW (11/6/09)

I just split the slurry from the first used of a Wyeast into 5 or 6 stubbies. Yeast fires up within 24hours in a starter even after 12 months in the fridge. I have had a 2124 going now for 2 1/2 years, no worries. I don't even bother with the serile water anymore just the left over beer from the fermenter.

Steve (I'm back)


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