ABV Question

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Hoonakwa

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My starting SG was 1.5 and my final is .992. According to the online calculator that is >63% ABV? Could that be right?
 
You could add a bit more sugar and restart the fermentation. Most wines will keep better with and ABV of 10% or more.

(Browse the wine shelves at the stores and check out the ranges and you will see a wide variety even in the same wine varietals (Chardonnay for example) BUT I doubt you'll find many with anything under 10% unless it's a specialty wine.)
 
You could add a bit more sugar and restart the fermentation. Most wines will keep better with and ABV of 10% or more.

(Browse the wine shelves at the stores and check out the ranges and you will see a wide variety even in the same wine varietals (Chardonnay for example) BUT I doubt you'll find many with anything under 10% unless it's a specialty wine.)

Those reading were while in the primary fermenter. The recipe said to rack the wine into a carboy and add 3/4 lbs of sugar. I am guessing this is a second fermentation? It is bubbling nicely. So how would I calculate the ABV now? After adding the sugar the SG went to 1.020, which is lower than in the primary fermentation. SOOO 1st fermentation SG started at 1.050 and went down to .992. Second fermentation SG started at 1.020 and we will see what is is in a month.
My question is how will I know what the ABV total is after the second fermentation?:?
 
My question is how will I know what the ABV total is after the second fermentation?:?
/QUOTE]

It's actually quite simple. You add the added SG to the initial reading and you need to add any added liquid volume (if you added syrup and not just sugar)
So.. assuming you added just sugar to calculate the increase in SG you subtract the SG just before you added the sugar (.992) from the FG (1.020) =.028
Your initial SG was 1.050 so, adding .028 sugar means the nominal true starting SG = 1.078.
 
Correctly or incorrectly I take the SG at the point just before I add additional sugar and subtract that from the SG after that sugar is added. Add that difference to the OG and then figure as if that total was where I started. SO:


SG Before adding additional sugar .992
SG AFTER adding additional sugar 1.020
Difference = .028
OG 1.050
1.050 + .028 = 1.078 Potential SG if it ferments all the way to .990 = 11.58% ABV
 
The foregoing three posts will give you approximately the correct value. You really need to account for the added volume when you added the sugar. The way I would do the calculation is to figure out the ABV before you added the sugar. Then multiply that by the volume of the must to figure out the ounces of ethanol in your must. Then, figure the increase in ABV due to second sugar addition, calculate the added ounces of ethanol. Add the two and divide by the final volume.

Having said all of that, the effect that I speaking of is to lower your ABV compared to the above calcuations by a small amount, like 0.5%, so I wouldn't sweat it.
 
Yup. There's always that pesky volume increase factor even when the sugar dissolves, it still adds volume. My simple syrup (2 parts sugar to 1 part water) ends up being between 2 2/3 cups - 2 3/4 cups liquid once the sugar is completely dissolved. In unscientific terms I would guess that equals the airspace between the sugar crystals in 2 cups of sugar.
 

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