[Bel Air Brewing]

Brewing an Imperial Stout today, using London Ale yeast. The website says it is good up to 11% ABV.
Never made a high gravity beer with this before. Mine came in at 1.093, or 22.2 Brix.

What has your experience been?

Looks like my efficiency is off a bit, as the recipe calculator said OG of 1.120.

[dannyjed]

When I make big beers my efficiency always goes down 10-15%. I pay less attention to what the yeast manufacturer states as the max alcohol tolerance and more to what the wort composition is. The more Crystal and Roasted grains the less attenuation.


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[denny]

When I make big beers my efficiency always goes down 10-15%. I pay less attention to what the yeast manufacturer states as the max alcohol tolerance and more to what the wort composition is. The more Crystal and Roasted grains the less attenuation.


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THIS.  Yeast attenuation rating is for comparing one yeast to another using a standard wort.  It doesn't necessarily reflect that attenuation you can expect.  Wort composition is the main factor in attenuation.

[Bel Air Brewing]

When I make big beers my efficiency always goes down 10-15%. I pay less attention to what the yeast manufacturer states as the max alcohol tolerance and more to what the wort composition is. The more Crystal and Roasted grains the less attenuation.


Sent from my iPhone using Tapatalk

THIS.  Yeast attenuation rating is for comparing one yeast to another using a standard wort.  It doesn't necessarily reflect that attenuation you can expect.  Wort composition is the main factor in attenuation.

Ok, understand. So with an OG of 1.093, any guess as to what we should expect? The ferment temp is 62F.

[denny]

When I make big beers my efficiency always goes down 10-15%. I pay less attention to what the yeast manufacturer states as the max alcohol tolerance and more to what the wort composition is. The more Crystal and Roasted grains the less attenuation.


Sent from my iPhone using Tapatalk

THIS.  Yeast attenuation rating is for comparing one yeast to another using a standard wort.  It doesn't necessarily reflect that attenuation you can expect.  Wort composition is the main factor in attenuation.

Ok, understand. So with an OG of 1.093, any guess as to what we should expect? The ferment temp is 62F.

I can make a guess if I see the recipe.  But it's only a guess.

[dmtaylor]

Usually a reasonable estimate for most yeasts and recipes:  Gravity points divided by 4.  That's specific gravity but ignoring the 1.0 in front.

So, for 1.093, that's 93 / 4 = 23 which is 1.023.

However Denny is correct, the real number is very dependent on yeast strain and recipe, so if we have that, including mash times and temperatures, then we can refine the estimate further.


P.S.  Another very rough guideline:  If the OG is 1.093, then you should end up with roughly 9.3% ABV, plus or minus a few tenths.  This works for many yeasts and recipes, but again... it depends.

[denny]

Usually a reasonable estimate for most yeasts and recipes:  Gravity points divided by 4.  That's specific gravity but ignoring the 1.0 in front.

So, for 1.093, that's 93 / 4 = 23 which is 1.023.

However Denny is correct, the real number is very dependent on yeast strain and recipe, so if we have that, including mash times and temperatures, then we can refine the estimate further.


P.S.  Another very rough guideline:  If the OG is 1.093, then you should end up with roughly 9.3% ABV, plus or minus a few tenths.  This works for many yeasts and recipes, but again... it depends.

Those are good ballpark numbers, Dave.

[Bel Air Brewing]

Usually a reasonable estimate for most yeasts and recipes:  Gravity points divided by 4.  That's specific gravity but ignoring the 1.0 in front.

So, for 1.093, that's 93 / 4 = 23 which is 1.023.

However Denny is correct, the real number is very dependent on yeast strain and recipe, so if we have that, including mash times and temperatures, then we can refine the estimate further.


P.S.  Another very rough guideline:  If the OG is 1.093, then you should end up with roughly 9.3% ABV, plus or minus a few tenths.  This works for many yeasts and recipes, but again... it depends.

Good to know, thank you.

[Bel Air Brewing]

When I make big beers my efficiency always goes down 10-15%. I pay less attention to what the yeast manufacturer states as the max alcohol tolerance and more to what the wort composition is. The more Crystal and Roasted grains the less attenuation.


Sent from my iPhone using Tapatalk

THIS.  Yeast attenuation rating is for comparing one yeast to another using a standard wort.  It doesn't necessarily reflect that attenuation you can expect.  Wort composition is the main factor in attenuation.

Ok, understand. So with an OG of 1.093, any guess as to what we should expect? The ferment temp is 62F.

I can make a guess if I see the recipe.  But it's only a guess.

Here goes:

20 lbs Pale
4 lbs Munich
1 lb 40 Crystal
1 lb 120 Caramel
1/2 lb Brown Malt
1/2 lb Chocolate Malt
1/4 lb Roasted Barley
1/4 lb Special B

Mash @ 142 = 30 minutes
Mash @ 154 = 30 minutes
Then raised to 170
90 minutes total time in Mash.

2.0 oz Willamette 6% AA FWH
2.0 oz Willamette 6% AA 30 minutes
2.0 oz Willamette 6% AA 5 minutes

Target IBU = 55

90 minute boil

Wyeast London Ale - #1028 (5th Generation)

OG - 1.093
Brix - 22.2

I tasted the wort after cooling. Balanced, bitterness & sweetness. Not bad. Fingers crossed on this one, as it is a first attempt.

[denny]

When I make big beers my efficiency always goes down 10-15%. I pay less attention to what the yeast manufacturer states as the max alcohol tolerance and more to what the wort composition is. The more Crystal and Roasted grains the less attenuation.


Sent from my iPhone using Tapatalk

THIS.  Yeast attenuation rating is for comparing one yeast to another using a standard wort.  It doesn't necessarily reflect that attenuation you can expect.  Wort composition is the main factor in attenuation.

Ok, understand. So with an OG of 1.093, any guess as to what we should expect? The ferment temp is 62F.

I can make a guess if I see the recipe.  But it's only a guess.

Here goes:

20 lbs Pale
4 lbs Munich
1 lb 40 Crystal
1 lb 120 Caramel
1/2 lb Brown Malt
1/2 lb Chocolate Malt
1/4 lb Roasted Barley
1/4 lb Special B

Mash @ 142 = 30 minutes
Mash @ 154 = 30 minutes
Then raised to 170
90 minutes total time in Mash.

90 minute boil

Wyeast London Ale - #1028 (5th Generation)

OG - 1.093
Brix - 22.2

I tasted the wort after cooling. Balanced, bitterness & sweetness. Not bad. Fingers crossed on this one, as it is a first attempt.

Rough top of the head math is that you've got around 13% low fermentables.  I wouldn't expect it to finish any lower than the 1.023 Dave predicted.  Which wouldn't be bad.  But like I said, it's only a guess.

[dmtaylor]

Thanks for the recipe.  Looks like a good one.  Based on it...

I stand by my previous numbers.  They should be almost completely dead on.  9.3% ABV.  And/or maybe 1.024 and 9.2%.  Close to that.

[erockrph]

I agree with the ballpark numbers from Denny and Dave. One other crucial factor is the yeast pitch. Fresh,  big, and healthy will get you a lot closer to the mid to low 1.020s FG

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[dmtaylor]

I agree with the ballpark numbers from Denny and Dave. One other crucial factor is the yeast pitch. Fresh,  big, and healthy will get you a lot closer to the mid to low 1.020s FG

In my experience, pitch rate is important to minimize lag time and get to the goal faster, while minimizing off-flavors.... but should not affect attenuation / FG, with enough patience.

[Bel Air Brewing]

Thanks for the recipe.  Looks like a good one.  Based on it...

I stand by my previous numbers.  They should be almost completely dead on.  9.3% ABV.  And/or maybe 1.024 and 9.2%.  Close to that.

Thanks for your input.
This recipe is taken from North Coast RIS, but a lot more base malt was added. About 8 lbs total extra base malt, 4 lbs Pale, 4 lbs Munich. My goal was to hit north of 10% ABV. But, we can live with 9.3% +/-.

[Bel Air Brewing]

I agree with the ballpark numbers from Denny and Dave. One other crucial factor is the yeast pitch. Fresh,  big, and healthy will get you a lot closer to the mid to low 1.020s FG

In my experience, pitch rate is important to minimize lag time and get to the goal faster, while minimizing off-flavors.... but should not affect attenuation / FG, with enough patience.

The yeast is fresh, being harvested about a month ago from an English Porter. Got it going yesterday, with added fresh wort, and today with more wort. It looks very good, and active. About 1/2 gallon slurry in a 6 gallon batch. And the aroma from this yeast is to die for!

edit: Yes, I know...another example of over-pitching. But it works for me!