Re-using yeast

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sup3rh3ro

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So my recent brew should be ready to be bottled this weekend (it will then be two weeks since it was brewed). I want to do another one and I was thinking I should be okay to bottle it, say Saturday, and brew the next batch on Sunday and just reuse the "old" yeast as it, right? It may have a bit of the old beer in it because I wouldn't wash it out, but it should still be fine, am I right?

Literally just taking it out of the bucket in sterilised jars over night (fridge maybe?), then brew the next and once cooled pitch the yeast from the jar?
 
Sure, as long as the jars,lids,covers and anything else that yeast touches is fine.
I have kept yeast from a previous brew for up to 4 months with no problem.
 
Lots of brewers (myself included) do just that. As long as your sanitation is on point (dunk the jar and lid in starsan solution before pouring the yeast slurry into the jar is fine), and you keep it refrigerated until ready to pitch, you'll be fine.
 
I used to use glass mason jars for doing this. I’ve switched over to using 64 oz plastic Snapple bottles. Make sure to clean and sanitize.

You can dump the entire yeast cake from the carboy into the bottle. Easy storage until you figure out what to do with your yeast. Easy to shake up and dump out too, either into your next batch or into a starter flask. Really an improvement IMHO…
 

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so bucket fermenter? I recommend brewing and bottling the same day.

Brew your next batch. While it's chilling just bottle your current beer. Once that's done hopefully your new beer is chilled enough to just dump in the bucket fermenter on the old cake.

there are guys here who have perpetuated a bucket fermenter several generations without any yeast harvesting or bucket cleaning.
 
there are guys here who have perpetuated a bucket fermenter several generations without any yeast harvesting or bucket cleaning

I did this with a carboy but only brave enough to do it for 2 beers in a row. That beer was a good one, and the fermentation was very strong within a few hours. S-04 on its 2nd beer did a wonderful job.

This was the brew that made me wonder if I really was pitching enough yeast, surely the previous 5G batch had produced enough yeast to over-pitch my wort, I did not pick up any obvious flaws with fermenting on a gazillion cells.

Not the approach I would use for banana flavor in my Hefe, but I was impressed with the results.
 
I've started fermenting and serving in the same keg.

If I have a beer I like to always have on tap...when it blows, I'll keep that keg sealed and cold, brew a fresh batch and then pitch it right into that old dirty keg and keep that yeast cake going.
 
It's a little bit like reusing underpants really. Some key pointers: make sure they're yours, clean and fit for purpose, before pitching them on brew day. I'd be very skeptical about claims expressed by online characters, about 'how they turn them inside out and/or back-to-front for months without  washing making a starter'. Be suspicious. I suspect their expectations differ significantly from mine.
 
so bucket fermenter? I recommend brewing and bottling the same day.

Brew your next batch. While it's chilling just bottle your current beer. Once that's done hopefully your new beer is chilled enough to just dump in the bucket fermenter on the old cake.

there are guys here who have perpetuated a bucket fermenter several generations without any yeast harvesting or bucket cleaning.


It works. Now I'm get slurry in beer bottles and just let the cap a little loose, to release pressure. 1 bottle os slurry is enough for 20 - 30 L batches. Also you can keep it for months
 
bottle it, say Saturday, and brew the next batch on Sunday and just reuse the "old" yeast as it, right?
Yes, that's fine, as is.*
Even if the yeast gets stored for a week in a jar in the fridge, not on the bottom of your fermentation bucket, with a lid lying on top.

* But don't pitch the whole cake's worth, as you'd be grossly over-pitching. The saved cake contains 4-5x the number of cells you pitched.
 
Good point! I just realised that! How do I figure out how much to pitch? And is it ok that it will include the trub and all the grain gunk?
 
How do I figure out how much to pitch?
Empirically. Say, 100g fresh, almost pure, concentrated yeast slurry was pitched in the first batch. You'd need to guess how trubby the wort is. You could assume the harvested slurry was 50% trub. So try pitching 200g freshly harvested yeast slurry in the next batch. Then decide whether you could add less (not so much trub in the slurry) or more in subsequent batches. Only you can decide what works best for you in your brewing/fermentation environment. Empirical observation is very effective and very cheap. Being consistent and limiting the amount of trub transfer to FV are good practices when repitching yeast.
 
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Yes, that's fine, as is.*
Even if the yeast gets stored for a week in a jar in the fridge, not on the bottom of your fermentation bucket, with a lid lying on top.

* But don't pitch the whole cake's worth, as you'd be grossly over-pitching. The saved cake contains 4-5x the number of cells you pitched.


What if you're brewing a barleywine or other strong beer that you're going to pitch on a session beer's yeast cake? That could be an exception, right?


I used to use glass mason jars for doing this. I’ve switched over to using 64 oz plastic Snapple bottles. Make sure to clean and sanitize.

You can dump the entire yeast cake from the carboy into the bottle. Easy storage until you figure out what to do with your yeast. Easy to shake up and dump out too, either into your next batch or into a starter flask. Really an improvement IMHO…


Good idea! Could you do the same with a 2L Coke bottle? I've thought about this for myself. After all, it's rated for pressure.
 
Empirically. Say, 100g fresh, almost pure, concentrated yeast slurry was pitched in the first batch. You'd need to guess how trubby the wort is. You could assume the harvested slurry was 50% trub. So try pitching 200g freshly harvested yeast slurry in the next batch. Then decide whether you could add less (not so much trub in the slurry) or more in subsequent batches. Only you can decide what works best for you in your brewing/fermentation environment. Empirical observation is very effective and very cheap. Being consistent and limiting the amount of trub transfer to FV are good practices when repitching yeast.
In this instance I used half a pack of salfale (it's only a 10l batch, I only ever brew small batches). Looking at it, it doesn't seem to have too much trub but then again it might be hard to tell if it is not washed out
 
Does anybody have a good technique for doing this with dryhopped beers? One that doesn’t involve washing or racking to secondary for dry hop? I have found the first to be a pain in the ass and the second to have oxidation risks.
 
Does anybody have a good technique for doing this with dryhopped beers? One that doesn’t involve washing or racking to secondary for dry hop? I have found the first to be a pain in the ass and the second to have oxidation risks.
I've done this with no issues; if I'm saving a yeast from a dry-hopped beer, I will only use it again on another dry-hopped beer. Added bonus, if I forget to label the jar, I can always tell which one is which; green!!!! What you can also do, is brew something that isn't dry-hopped; when it's time to save the slurry, save two jars. One can be for dry-hopped beers, the other for non-dry hopped. On a standard 5g batch I can usually get two full quart mason jars of good slurry, but I only take one; otherwise my fridge would be full of yeast!!
 
I limit trub carry over into the FV and have come to the best repitches for my brewery are as follows. slurry after a 5 G ferment.
Ale- This slurry will do 4 batches of 1.050 so you could save 4- 1 pint jars and pitch one on a dry hopped and not worry about repitching that cake.
Kolsch (2565-house yeast) can do 3 1.050 batches.
Lager- I'll repitch one cake on 10 gal.
I'm with McMullan on the sensory eval's, clear fermenters and the depth of krausen and rising temps in a short time.
When I do a big one 1.100+ I make a small one for a starter and pitch the whole cake,that one won't be saved.
Last but not least , get to know your yeast, i couldn't tell you anything about US05 but Notty and BRY97 are always in the fridge.
 
Yes, one can save yeast from a dry hopped primary and it does work. But I still prefer dry hopping in a secondary for the following reasons
If I’m making a stout at 5-6 abv and I’m dry hopping, I’ll dry hop in the secondary because usually, I make a light stout first followed by a imperial stout that I won’t want those hops in.

Now if I’m making a ipa , dry hop with citra or your choice of hop, and I want the next ipa to have some of that in it I will not dry hop in a secondary, but, if I want to make a very different tasting ipa I will dry hop in the secondary.

My favorite reuse of yeast is when I make my burton light. This gets 2 oz of goldings at 60. I’ve ever had a problem reusing this yeast for any beer I make and I store all my recycled yeast in growls here type bottles.
 
I've done this with no issues; if I'm saving a yeast from a dry-hopped beer, I will only use it again on another dry-hopped beer. Added bonus, if I forget to label the jar, I can always tell which one is which; green!!!! What you can also do, is brew something that isn't dry-hopped; when it's time to save the slurry, save two jars. One can be for dry-hopped beers, the other for non-dry hopped. On a standard 5g batch I can usually get two full quart mason jars of good slurry, but I only take one; otherwise my fridge would be full of yeast!!

Ha. I just always assumed I shouldn't do this. I've got an IPA finishing fermentation w/ Hothead and I'm about to dryhop w/ Citra. My next one will probably also be a Citra IPA because I have a freezer full of it, so I'll try this out.
 
In this instance I used half a pack of salfale (it's only a 10l batch, I only ever brew small batches). Looking at it, it doesn't seem to have too much trub but then again it might be hard to tell if it is not washed out
It doesn't really matter. I mainly brew half batches (12L) these days. It's so easy at this volume I brew more often and pitch even fresher yeast. For me, it's a no brainer these days. Since the pandemic I stopped giving beer away. I readjusted the output. I'm saving money and getting to change beers more often. For me, it's a win-win-win. There's not much better than rediscovering the joy of home brewing, with a little knowledge onboard. I can't believe how close I've got to spending some serious coin on  upgrading upscaling to a 50L system. It's a load of shiny nonsense, way above what a home brewer needs. I was quite skeptical about advice on HBT re going for a system volume twice what you aim to brew, but, as I've come to realise, it makes so much sense. Pretty much any system on the market is going to function better at half its capacity, in pretty much most respects.
 
I've started fermenting and serving in the same keg.

If I have a beer I like to always have on tap...when it blows, I'll keep that keg sealed and cold, brew a fresh batch and then pitch it right into that old dirty keg and keep that yeast cake going.
I've also been fermenting and serving from the same keg. Do you prefer a floating dip tube, cut tube, or bent tube for the purposes of saving yeast?
 
I've also been fermenting and serving from the same keg. Do you prefer a floating dip tube, cut tube, or bent tube for the purposes of saving yeast?
well depends HOW you wish to reuse the yeast.

At first I used the old dip tube. No cutting or bending. At the end of fermentation I would burp the yeast cake out into a couple small mason jars and put them in the fridge for future use in a variety of beers. When I tapped the keg for drinking I just discard the first pint or two with any residual yeast/trub and then enjoy clear beer.

Now I use a floating dip tube. All the yeast remains inside the keg and I enjoy clear beer on the first pint. When the keg pops, a lot of yeast is expelled and I just toss it out since it's in an unsterile pint glass that I've been drinking from. I will leave that keg sealed and cold, either in the kegerator or move it to cold storage (freezer with Inkbird). I then will brew up another batch, same type or similar style/characteristic and then dump it in that keg on the residual yeast (there is still plenty) and let it go again.
 
well depends HOW you wish to reuse the yeast.

At first I used the old dip tube. No cutting or bending. At the end of fermentation I would burp the yeast cake out into a couple small mason jars and put them in the fridge for future use in a variety of beers. When I tapped the keg for drinking I just discard the first pint or two with any residual yeast/trub and then enjoy clear beer.

Now I use a floating dip tube. All the yeast remains inside the keg and I enjoy clear beer on the first pint. When the keg pops, a lot of yeast is expelled and I just toss it out since it's in an unsterile pint glass that I've been drinking from. I will leave that keg sealed and cold, either in the kegerator or move it to cold storage (freezer with Inkbird). I then will brew up another batch, same type or similar style/characteristic and then dump it in that keg on the residual yeast (there is still plenty) and let it go again.
Brilliant, thanks. Pretty much what I've been doing as well. Those first pours of yeast cake with an unmodified dip tube can be really slow!
 
Brilliant, thanks. Pretty much what I've been doing as well. Those first pours of yeast cake with an unmodified dip tube can be really slow!
I didn't have any issues with the full length dip tube. Yeast came out pretty fast. A lot will depend on the keg pressure.
 
So how much yeast trub from fermented batch would a guy need to have the equivalent of one dry yeast package. 2 for lagers
 
My repitch rates for sediment from a 5 gal ferment of ale would be 1/4 , for Kolsch 1/3 and for lager 1/2. This allows me to repitch subsequent batches without over pitching.
 
I was already taking slurry from a fermenter and using it to ferment new beer, but with varying success. I’ve had a few spoiled beers so I’ve given up on that and I haven’t had a single case of my beer spoiling since.
I wonder if the slurry should be kept in a sealed jar in the refrigerator or should the jar be left slightly open?
 
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