Reusing yeast for high gravity beer

[toddo97]

I have a batch of imperial stout that I'll be bottling this weekend and would like to turn around and make another batch in the next week or two. I used Imperial's The Darkness and would like to just add the next batch on top of it. Would this be advisable? I can also pitch US-04/05/Kviek if it needs some more horsepower.

 

[brownni5]

General advise is to not reuse yeast that has been used for a high gravity beer - the yeast get really beat up in a stressful environment. Most people stay under 1.060 or so if reusing yeast, but can probably stretch that a bit. If it we're me, I'd look to different options for yeast, but, hey, how will you know how far you can go if you never go too far?

 

[toddo97]

Maybe I'll copitch with Kviek and make a Brut Imperial Stout

 

[isomerization]

Maybe I'll copitch with Kviek and make a Brut Imperial Stout

This sounds like it’s in jest, but just to be safe kveik yeasts do not typically attenuate like that, you’d need to add glucoamylase. Just FYI.

 

[Jayjay1976]

Pull a few ounces of the slurry and spin up a new starter then build it to a sufficient size for the beer you're brewing. Old, weak cells will be replaced by new healthy cells ready to ferment your next batch. I've brewed 1.060 stout as a starter for an imperial stout, saving a few liters of the slurry but it was sluggish because the cells were tired and weak. I wouldn't do it the same way again. Imperial stout wort is a stressful environment as it is, and pitching old, grey cells may not get it done and could lead to off-flavors.

 

[Jayjay1976]

I've just bottled a 1.070 stout that was fermented with Hornindal, it didn't fully attenuate even with heat but it sure tastes good as a sweet stout.

 

[odie]

I’ve got a stout with 05 that’s about ready to keg. I’m also about to brew an imperial stout that also calls for 05. I’m wondering if I could rack the stout and immediately pour the imperial on the cake in the fermenter? The stout was screened pretty good into the fermenter so trub should be minimal

 

[Jayjay1976]

I've never tried it with 05 myself, but lots of brewers do this. What was the OG of the stout you're kegging?

 

[toddo97]

This sounds like it’s in jest, but just to be safe kveik yeasts do not typically attenuate like that, you’d need to add glucoamylase. Just FYI.

I was joking because of the violent fermentation I've gotten with the kveik I've used, but good to know for sure

 

[toddo97]

Pull a few ounces of the slurry and spin up a new starter then build it to a sufficient size for the beer you're brewing. Old, weak cells will be replaced by new healthy cells ready to ferment your next batch. I've brewed 1.060 stout as a starter for an imperial stout, saving a few liters of the slurry but it was sluggish because the cells were tired and weak. I wouldn't do it the same way again. Imperial stout wort is a stressful environment as it is, and pitching old, grey cells may not get it done and could lead to off-flavors.

The stout I'm getting ready to bottle started a bit north of 1.100 so I might be pushing it with that. Maybe I'll see how a 100% kveik fermentation turns out.

 

[odie]

I've never tried it with 05 myself, but lots of brewers do this. What was the OG of the stout you're kegging?

My notes are at home but I’m thinking around 1.080 but that’s including a pound of lactose and some cacao powder which is not fermentable.

It’s an imperial maple stout that also calls for cacao and US-05 yeast. So I think the flavor profile of the first beer’s yeast/trub works well with the second

 

[Jayjay1976]

My notes are at home but I’m thinking around 1.080 but that’s including a pound of lactose and some cacao powder which is not fermentable.

It’s an imperial maple stout that also calls for cacao and US-05 yeast. So I think the flavor profile of the first beer’s yeast/trub works well with the second

IMHO, 1.080 is pushing it regarding the viability of the yeast after fermentation. As @brownni5 said, 1.060 is about the ceiling when it comes to pitching on a yeast cake.

If I were taking the trouble, time, and expense of brewing an imperial stout I would make a starter from a bit of that slurry. The 1.080 cake you have is likely mostly made up of dead yeast cells and other stuff you don't want in your next batch.

 

[Jayjay1976]

The stout I'm getting ready to bottle started a bit north of 1.100 so I might be pushing it with that. Maybe I'll see how a 100% kveik fermentation turns out.

If the kveik stalls out before reaching your target gravity you might want to try pitching fresh yeast to help it finish out. Also, add half a packet of CBC-1 at bottling time in case the residual yeast in suspension aren't up to the task of bottle conditioning. Nothing worse than a flat, syrupy-sweet, under-attenuated mess of an imperial stout. Oh and to avoid all that mess, aerate the hell out of it at pitching time.

 

[toddo97]

I've just bottled a 1.070 stout that was fermented with Hornindal, it didn't fully attenuate even with heat but it sure tastes good as a sweet stout.

I have some glucoa

If the kveik stalls out before reaching your target gravity you might want to try pitching fresh yeast to help it finish out. Also, add half a packet of CBC-1 at bottling time in case the residual yeast in suspension aren't up to the task of bottle conditioning. Nothing worse than a flat, syrupy-sweet, under-attenuated mess of an imperial stout. Oh and to avoid all that mess, aerate the hell out of it at pitching time.

I got some glucoamylase for my current batch in case I had a stuck fermentation I can try. I might try throwing in some dry yeast along with the kveik to help cover my bases. I'm shooting for a bigger OG for the next one to make a big ol' raspberry imperial milk stout.

 

[odie]

IMHO, 1.080 is pushing it regarding the viability of the yeast after fermentation. As @brownni5 said, 1.060 is about the ceiling when it comes to pitching on a yeast cake.

If I were taking the trouble, time, and expense of brewing an imperial stout I would make a starter from a bit of that slurry. The 1.080 cake you have is likely mostly made up of dead yeast cells and other stuff you don't want in your next batch.

My notes say 1.081 but how much of that is lactose? Pulled a FG sample but lots of silt so letting it settle before reading. BTW just tapped my first hefe...I’m pretty happy with it. Taking samples to a bbq for critique