AG Imperial Stout Help

[BottlesCansCraft]

Hi,

I have been researching a strong, sweet imperial stout recipe and got brewing the other weekend, but didn't think very well ahead, and couldn't measure the original gravity as my my hydrometer only goes up to 1080. Brewer's friend said my OG would be a whopping 1180 with a FG of 1065. I can guarantee the wort was atleast 1100 from how the hydrometer essentially sat on top the brew, but can't know for certain

To get there I have heard positive stories with US05 and double pitching, so as this was only a small batch of 7 litres, I did exactly this. Currently after a week I am down to 1083 and will keep an eye on it.

If it struggles should I just add another packet of US05 to help it to the finish?

I take it there is no other way of knowing how strong this really is when finished?

Cheers

 

[Banbeer]

I take it there is no other way of knowing how strong this really is when finished?

just drink a few when it's all finished and if you wake up with the feeling that your partners eyes are burning into your back then it's probably strong.

 

[strange-steve]

Brewer's friend said my OG would be a whopping 1180 with a FG of 1065. I can guarantee the wort was atleast 1100 from how the hydrometer essentially sat on top the brew, but can't know for certain

That's insane Don't forget though that efficency tends to drop off as the gravity goes up, so you'd need to take that into account when predicting the OG. If it was that high (or even close to it) I can tell you from experience that you'll struggle to naturally carbonate this because there's more than enough fermentables in there for the yeast to kill itself with alcohol, so I hope you have a keg system.

My RIS had an OG of 1.143 and it fermented out to just over 16% abv, and a repitch of kveik, and champagne yeast at bottling did nothing and I ended up opening all the bottles and dumping them into a corny keg.

I'll be keeping an eye on this though!

 

[BeerCat]

That would be 15% ABV and extremely sweet. A cola is around 1040 for comparison and fermentation would likely stall due to massive amounts of sugar. Get a refractometer for measuring pre boil gravity. they are pretty cheap

@strange-steve Did you keep a bottle to see if it ever carbed? I have a 15.5% to bottle and hoping ec118 will do the job

 

[strange-steve]

Did you keep a bottle to see if it ever carbed? I have a 15.5% to bottle and hoping ec118 will do the

Yes I still have a plastic bottle which has been kept at room temperature for just over a year now and there's no sign of carbonation at all. Fingers crossed you have more success

 

[BottlesCansCraft]

That's insane Don't forget though that efficency tends to drop off as the gravity goes up, so you'd need to take that into account when predicting the OG. If it was that high (or even close to it) I can tell you from experience that you'll struggle to naturally carbonate this because there's more than enough fermentables in there for the yeast to kill itself with alcohol, so I hope you have a keg system.

My RIS had an OG of 1.143 and it fermented out to just over 16% abv, and a repitch of kveik, and champagne yeast at bottling did nothing and I ended up opening all the bottles and dumping them into a corny keg.

I'll be keeping an eye on this though!

I hadn't really of though of this. I don't have a keg system yet, so just getting by with bottles. Off the back of this:

> Is there a particular abv where bottle conditioning begins to struggle?
> would any yeast I repitch simply die?
> how do breweries get their 12%ish impys to carbonate in bottles?

Thanks for the wisdom

 

[BottlesCansCraft]

Calling to all impy heads:

If anyone is still looking at this, I repitched with US05 and it's done nothing, gravity is at 1080. It does however taste great, and I'll add some cocoa and vanilla pods now and leave for a few more days.

Gravity is still at 1080.

Any suggestions for things to change on a future brew? what % is roughly successful for a bottle conditioned impy?

 

[strange-steve]

I hadn't really of though of this. I don't have a keg system yet, so just getting by with bottles. Off the back of this:

> Is there a particular abv where bottle conditioning begins to struggle?
> would any yeast I repitch simply die?
> how do breweries get their 12%ish impys to carbonate in bottles?

Thanks for the wisdom

Sorry I just saw this.
When you go over about 12% or so then it might start getting difficult.
Repitching into this is going to be really hard on the yeast, and depending on the strain could really struggle to do anything.
I'm not sure how commercial breweries do it, maybe a very alcohol tolerant strain, bottling before FG is reached, force carbed...

Calling to all impy heads:

If anyone is still looking at this, I repitched with US05 and it's done nothing, gravity is at 1080. It does however taste great, and I'll add some cocoa and vanilla pods now and leave for a few more days.

Gravity is still at 1080.

Any suggestions for things to change on a future brew? what % is roughly successful for a bottle conditioned impy?

If your OG was as high as you say at 1.180 then it's currently >13% ABV which is probably at or beyond the limit of US05. You might be lucky and it eventually carbonates given enough time, it's impossible to say really. Lessons for the future, an OG of 1.180 is huge and was never going to ferment out.

 

[BottlesCansCraft]

Cheers @strange-steve, appreaciate you getting back on my other questions.

Would it make more sense to just go with a champagne yeast/turbo yeast from the start? Are these considered "clean" in taste like US05 or could they change the flavour? Do you have experience with a good choice?

Attempting again, I may move it down to a max of OG 1.13/1.14, it still maybe crazy, but It might have more success?

 

[strange-steve]

Would it make more sense to just go with a champagne yeast/turbo yeast from the start?

Maybe not from the start, but perhaps 2 or 3 days into fermentation. That would prevent it from changing the flavour too much while giving it a more hospitable environment.

Are these considered "clean" in taste like US05 or could they change the flavour?

I've never used them for primary fermentation so I don't know what you'd end up with.

Do you have experience with a good choice?

I used a blend of Voss and hornindal kveik yeasts which fermented up to about 16%.

Attempting again, I may move it down to a max of OG 1.13/1.14, it still maybe crazy, but It might have more success?

That's still really high. Mine had an OG of 1.143 and it was a right pain in the ass. Never carbonated even after a year. In future I don't think I'd go higher than about 1.110.