BM45 and the 15% ABV Wall

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FunkedOut

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Last night, I pitched some BM45 into a RJS Super Tuscan kit.
This morning, SG is up to 1.110.
Math indicates that this wine will reach 15% ABV (the advertised max tolerance of BM45) at an FG of 1.000.

Assuming that the SG does not increase any more (sugars still hiding in the skin packs),
assuming full attenuation down to 0.992,
math indicates an ABV of 16%.

I am wanting this wine to ferment dry.
Should I be worried about BM45 sputtering out at the 15% mark?
What has been your experience with the upper end of BM45 tolerance?

Should I add some EC1118 in the latter part of fermentation?
I am planning an 8 week EM for this kit.
Thinking I could add the EC1118 at an SG of 1.010 as I seal it up for the remainder of the EM.

Thoughts?
 

stickman

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I don't have experience with BM45 so can't comment on that part of the question. As far as adding EC1118, my opinion is, it would be best accomplished by pulling out a small portion of the must right now, even just a quart, and adding the EC1118 and allow it to ferment separately. When the main batch drops down to 1.010 then add the EC1118 portion and allow to complete per your plan. Often when dry yeast is tossed into high ABV must it fails to adapt, the odds are much better if the yeast is already adapted to the high alcohol level.
 

sour_grapes

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FWIW, I have had BM45 take me from 1.106 to 0.991.
 

FunkedOut

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I just set aside a quart of the must and sprinkled 5g of EC1118 on top.
I didn't bother with the rehydration procedure on this bit, mainly because I did not want to add a bunch a nutrient to the main fermentation that late in the game.

I recently added a pack of EC1118 to a 10% beer (Imperial Stout) that finished too sweet.
It took about 4-5 days for the yeast to take off, but it's been chugging away for over week since.

Adding the EC1118 is a safe bet, and allowing it to get started on a low ABV must is a second safety net.
I think I just made my own BM4X4...

Thanks for your help.
 

Rocky

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Last night, I pitched some BM45 into a RJS Super Tuscan kit.
This morning, SG is up to 1.110.
Math indicates that this wine will reach 15% ABV (the advertised max tolerance of BM45) at an FG of 1.000.

Assuming that the SG does not increase any more (sugars still hiding in the skin packs),
assuming full attenuation down to 0.992,
math indicates an ABV of 16%.]

Not that it makes a whole lot of difference in your situation, but what formula are you using to compute ABV? With the numbers you show, I get an SG of less than 14.5% for your first case and about 15.5% for your second case. I use (ISG-FSG)x131=ABV.
 

FunkedOut

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I use BeerSmith for my brewing purposes. Lots of great features including calculations.
This package is barely useful for making wine, but it is a place for me keep all my notes.

The calculation employed by the software uses the same formula you list above.
The complication is that the factor of 131 is not constant. It increases as the ABV increases.

Using the software, I calculated this factor's value for a few data points and derived the following formula for the factor that gets you pretty close:
factor = (53 x ABV) + 128

So for 15%, that works out to 135.95.
And for 16%, that works out to 136.48.
 

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