Imperial stout OG 1.160, US-05

[Sskytthe]

Hi everyone.

So I brewed an imperial stout yesterday going for an OG of 1.140
After boiling for 7 hours ai ended at 1.138 and thought it was as close as I could get.
When the wort cooled the OG ended at 1.160. So my question is basically if you think my yeast can do the job?
I used two packs of US-05 and bought a pack of Lanvin wine yeast as a safety.

How far can US-05 go?

I've used 15g yeast nutrients as a side note.

Thanks in advance.

 

[Miraculix]

Wine yeast won't help, it can only metabolize short sugars and these are eaten first by the beer yeast, which means they are gone once the 05 quits. You can add water to lower the og, you can boil hops in it first if you don't want to thin out the bitterness.

 

[Albany brew guy]

You can add San Diego super yeast (WLP 090) but you will still have two more percentage points to get. Might I suggest adding top-off water and diluting a bit? 17% seems to be your current ABV and while a victory in some sense if you hit, completely unnecessary.

 

[Sskytthe]

Wine yeast won't help, it can only metabolize short sugars and these are eaten first by the beer yeast, which means they are gone once the 05 quits. You can add water to lower the og, you can boil hops in it first if you don't want to thin out the bitterness.

How much alcohol will the 05 produce? Cause I don't mind a high FG as I'm considering barrel aging it after fermentation and have read somewhere that it's preferred to have a FG around 1.030-1.040. Correct me if om wrong

 

[AlexKay]

I used US-05 on an American Barleywine that started at 1.135. FG was 1.041 (70% attenuation), and (six months later) it tasted pretty good, definitely not too sweet. However, fermentation crawled along for a full month. I've had much better luck with Nottingham on high-gravity ales, but that's not so helpful, seeing as you've already pitched. Good luck, and let us know how it goes!

 

[jerrylotto]

You are going to stall out around 1.045. You can then pitch an STA-1 enhanced yeast like WLP-099 and you probably can slowly get another 10 points over the next two weeks. I just did that with a Bourbon Stout.

 

[VikeMan]

How much alcohol will the 05 produce?

It's possible you'll reach your wort/yeast combination's full potential apparent attenuation before bumping up against US-05's true ABV tolerance level.

What were your grain bill, mash temp, and mash length?

After boiling for 7 hours ai ended at 1.138 and thought it was as close as I could get.
When the wort cooled the OG ended at 1.160.

That's quite a change between your hot and cooled gravities. How hot was the wort when you initially measured it?

 

[DuncB]

Ahh @Sskytthe
Found your question.
You could consider reoxygenating after a day or two and or pitching some Nottingham as well. Yeasts strains are like people, they can only eat so much regardless of how much is on the plate. Some yeasts can eat more ( attenuation ), much as some people can.
But your US 05 and or Nottingham will struggle to get you a low FG.

 

[Miraculix]

How much alcohol will the 05 produce? Cause I don't mind a high FG as I'm considering barrel aging it after fermentation and have read somewhere that it's preferred to have a FG around 1.030-1.040. Correct me if om wrong

I think it will end up between 1.04 and 1.05 for about 14-15% abv. This is about the maximum that you can get with "normal" yeast in a beer, without doing special things like using diastatic yeast. But even that diastatic yeast might not go further as the alcohol level is already pretty high and maybe above the yeast's limit. I'd just toss in an additional pack of Nottingham (cannot go wrong with that one) and see where it ends up.

 

[McMullan]

The 'trick' is to add more yeast at the beginning. Above about 5% ethanol, yeast (metabolism) slow down and get increasingly stressed as the % increases further. They drop out at a rate, they don't just all give up at a certain point. This is why you need to pitch on the massive side, imo. Oxygenating with dry yeast is pretty pointless regardless and possibly has more risks than anything else. I think you've got time to sprinkle in a few more packs.

 

[Sskytthe]

I think it will end up between 1.04 and 1.05 for about 14-15% abv. This is about the maximum that you can get with "normal" yeast in a beer, without doing special things like using diastatic yeast. But even that diastatic yeast might not go further as the alcohol level is already pretty high and maybe above the yeast's limit. I'd just toss in an additional pack of Nottingham (cannot go wrong with that one) and see where it ends up.

I'll get me a pack of Nottingham

 

[Sskytthe]

It's possible you'll reach your wort/yeast combination's full potential apparent attenuation before bumping up against US-05's true ABV tolerance level.

What were your grain bill, mash temp, and mash length?



That's quite a change between your hot and cooled gravities. How hot was the wort when you initially measured it?

Just below boiling point

 

[VikeMan]

@Albany brew guy... have to quote you manually because your reply was within your quote box for the OP...

"17% seems to be your current ABV and while a victory in some sense if you hit, completely unnecessary."

How did you arrive at 17%?

 

[Sskytthe]

Just below boiling point

I did a double mash
First mash with half of the base malts
20min at 45c
20min at 58c
40 min 65c
10min at 75c

Second mash was a bit simpler
60min at 65c
Then I added my roasted barley and chocolate and mashed for 20 more minutes at 65c

It's possible you'll reach your wort/yeast combination's full potential apparent attenuation before bumping up against US-05's true ABV tolerance level.

What were your grain bill, mash temp, and mash length?



That's quite a change between your hot and cooled gravities. How hot was the wort when you initially measured it?

Grain was
75.8% marris otter
3.8% golden promise
5.2% flaked oats
3.8% crystal malt
3.8% roasted barley
5.1% chocolate malt
2.5% honey

I did a double mash

First mash with half of the base malts

20min at 45c

20min at 58c

40 min 65c

10min at 75c


Second mash was a bit simpler

60min at 65c

Then I added my roasted barley and chocolate and mashed for 20 more minutes at 65c

Boiling for 7-8 hours

 

[Sskytthe]

I used US-05 on an American Barleywine that started at 1.135. FG was 1.041 (70% attenuation), and (six months later) it tasted pretty good, definitely not too sweet. However, fermentation crawled along for a full month. I've had much better luck with Nottingham on high-gravity ales, but that's not so helpful, seeing as you've already pitched. Good luck, and let us know how it goes!

I will! Thanks. I'll keep the Nottingham in mind for next big brew!

 

[VikeMan]

I did a double mash
First mash with half of the base malts
20min at 45c
20min at 58c
40 min 65c
10min at 75c

Second mash was a bit simpler
60min at 65c
Then I added my roasted barley and chocolate and mashed for 20 more minutes at 65c

Grain was
75.8% marris otter
3.8% golden promise
5.2% flaked oats
3.8% crystal malt
3.8% roasted barley
5.1% chocolate malt
2.5% honey

I did a double mash

First mash with half of the base malts

20min at 45c

20min at 58c

40 min 65c

10min at 75c


Second mash was a bit simpler

60min at 65c

Then I added my roasted barley and chocolate and mashed for 20 more minutes at 65c

Boiling for 7-8 hours

Back of the envelope (a couple of envelopes, given your two mashes), I'd estimate this to get about 76% apparent attenuation, landing around 16% ABV, if the US-05 is up to the task. US-05 has a published ABV tolerance of 9-11%, which IMO is conservative. That said, 16% is probably a stretch. A lot depends on yeast health and pitch rate.

ETA: Meant to mention, that 7 hour boil might have made the wort slightly less fermentable, due to maillard reactions. I kind of doubt that it would be very significant, but I've never done a 7 hour boil.

 

[Sskytthe]

Back of the envelope (a couple of envelopes, given your two mashes), I'd estimate this to get about 76% apparent attenuation, landing around 16% ABV, if the US-05 is up to the task. US-05 has a published ABV tolerance of 9-11%, which IMO is conservative. That said, 16% is probably a stretch. A lot depends on yeast health and pitch rate.

ETA: Meant to mention, that 7 hour boil might have made the wort slightly less fermentable, due to maillard reactions. I kind of doubt that it would be very significant, but I've never done a 7 hour boil.

I've tried a 8 hours boil before which ended with an og of 1.09 and fg of 1.03 same recipe but the difference being the efficiency (in brewfather). Turned out really well except ofcourse I didn't hit OG at all

 

[BrewnWKopperKat]

[barley wine, US-05] fermentation crawled along for a full month.

Good observation.

In the Fermentis Tips & Tricks brochure, on page 28, there are a couple of charts that show apparent attenuation over time with 13.5P and 18P worts at 68F. The charts suggest that US-05 can be slower in higher gravity situations.

 

[Albany brew guy]

@Albany brew guy... have to quote you manually because your reply was within your quote box for the OP...

"17% seems to be your current ABV and while a victory in some sense if you hit, completely unnecessary."

How did you arrive at 17%?

Assuming a FG of 1.025
(OG-FG)*131.25
(1.160-1.025)*131.25 = 17.72% ABV

Assuming a FG of 1.035
(OG-FG)*131.25
(1.160-1.035)*131.25 = 16.40% ABV

So - 17% is about middle there -reasonable estimate

 

[VikeMan]

Assuming a FG of 1.025
(OG-FG)*131.25
(1.160-1.025)*131.25 = 17.72% ABV

Assuming a FG of 1.035
(OG-FG)*131.25
(1.160-1.035)*131.25 = 16.40% ABV

So - 17% is about middle there -reasonable estimate

Sure, that's how ABV is computed. But how did you estimate the FG(s) without knowing anything about the grain bill or mash parameters?

 

[Albany brew guy]

Sure, that's how ABV is computed. But how did you estimate the FG(s) without knowing anything about the grain bill or mash parameters?

BJCP standards for a RIP is between 1.018 and 1.030. Guessing that with that much of an OG, the probability of finishing on the high end was likely.

 

[VikeMan]

BJCP standards for a RIP is between 1.018 and 1.030. Guessing that with that much of an OG, the probability of finishing on the high end was likely.

Yeah. Unfortunately, yeast do what they can do with the wort they're given. They hardly ever read the BJCP guidelines, in much the same way that they don't read yeast manufacturers' published attenuation ranges.

 

[Albany brew guy]

Yeah. Unfortunately, yeast do what they can do with the wort they're given. They hardly ever read the BJCP guidelines, in much the same way that they don't read yeast manufacturers' published attenuation ranges.

true enough. Just used to hitting gravity - also realizing that in this case, topping off to bring the OG down, also brings the volume up, so more beer

 

[jerrylotto]

I'm curious WHY you did a 7-8 hour boil and how you kept from boiling it dry? Was it boiled uncovered and water added to maintain volume?

 

[Sskytthe]

I'm curious WHY you did a 7-8 hour boil and how you kept from boiling it dry? Was it boiled uncovered and water added to maintain volume?

Tbh I wanted to try it out..I wanted to caramelize the sugar for flavour, color and thickness.
I've went from 5gallon to around 2 during the boil.