Gravity question on fruit beer - Home Brew Forums

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03-01-2012, 05:12 AM   #1
sirmichael
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Feb 2012
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A few weeks back I brewed an all extract wheat. This past Saturday I mashed up and boiled 11 cups of huckleberries and racked my five gallons on the huckleberry purée. I took a gravity reading before primary fermentation (1.057) and I had a steady reading for three days (1.018) before moving to secondary. I did not take another reading after adding the huckleberries and moving to secondary. Can I still find out my ABV after secondary is complete? There is a very nice krausen layer going on right now.

Thanks.

03-01-2012, 03:07 PM   #2
TopherM

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Mar 2011
St. Petersburg, FL
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You would need to find the sugar contribution of the huckleberry puree to find out your ABV.

Looks like there are 2.4 grams of sugar per 28 grams of huckelberries. I have no idea how many grams of huckelberries fit in 11 cups.

If you could approximate the weight of 11 cups of the berries, we could figure out the sugar contribution and overall ABV.
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03-01-2012, 07:00 PM   #3
sirmichael
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Feb 2012
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So does this math make sense.

11 cups of huckleberry.
16 cups in a gallon.
4.5 pounds of huckleberries per gallon
2.4 g of sugar per 28 g of huckleberries = .0857 g of sugar per g of huckleberries

11/16 =.6875 gallons
.6875 x 4.5 lbs = 3.09 pounds

454g/lb

3.09 x 454 = 1402 g

1402 x .0857 = 120.17 g of sugar from huckleberries or .265 lbs of sugar

Added 160 g of sugar to sweeten huckleberries

160/454 = .352 lbs of sugar

Total sugar added = .617 lbs at 46 ppg = 28.4.

03-01-2012, 07:07 PM   #4
sirmichael
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Feb 2012
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I forgot to add that it's a 5 gallon batch. Assuming the 28.4 is somewhat close, I would then divide it by 5 right? So 5.68.

Brewing is hard on my math skills.

03-01-2012, 08:20 PM   #5
TopherM

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Mar 2011
St. Petersburg, FL
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You've asked the wrong guy to check your math, but assuming it's all right, and you added 28.4 grams (0.617 lbs) of extra fermentables with the fruit, that would have added 0.006 gravity points, so you are at about 1.063 aggregate OG, 1.018 FG = 6% ABV.

Without the Huckelberries, you would be at about 5.3% ABV, so the fruit and sugar in secondary add about 0.7% ABV to the overall brew.

That sounds about right to me! I have a math headache now!
__________________
Primary #1 - Midnight Ryeder (Midnight Wheat and Rye)
Primary #2 - Florida Weiss
Primary #3 - Kane-DOH APA (Honey Citra APA)
Secondary #1 - Downtown Flanders Brown (brewed August 2012)
Keg #1 - Raspberry Florida Weiss
Keg #2 - Cinnamon Raisin Cider
Keg #3 - NONE!
Bottled - NONE!

03-01-2012, 08:32 PM   #6
huge1s
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Jul 2011
Monument, CO
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03-02-2012, 12:57 AM   #7
sirmichael
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Feb 2012
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Thanks everyone. I guess as long as it tastes good I don't really care what the ABV comes out too.