The "dragon" wants me to make an AG beer with fruit (blackberries are all around at the moment) I was thinking probably just pale malt with perhaps cascade or amarillo to compliment the fruit. The plan (feel free to offer advice) is to add the fruit (pulped?) about two thirds through primary fermentation.
The question is .....if I add fruit part way through (or any other sugar for that matter) how do I work out the final ABV?
HOW DO I CALCULATE ALCOHOL FROM FRUIT?
- trucker5774
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HOW DO I CALCULATE ALCOHOL FROM FRUIT?
John
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
- trucker5774
- Falling off the Barstool
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- Joined: Sun May 17, 2009 12:20 pm
- Location: North Devon
Re: HOW DO I CALCULATE ALCOHOL FROM FRUIT?
I have since noticed a thread on brewing a clear liquid to imitate a weak vodka. They add sugar late in fermentation............if anyone has the formula to calculate ABV it would be helpful to that thread to.
Is it as simple as adding on the increase in gravity then the usual calculation? This obviously won't work in the case of fruit as the sugar will take time to release, unless it's added as an "extract"
Any ideas?
Is it as simple as adding on the increase in gravity then the usual calculation? This obviously won't work in the case of fruit as the sugar will take time to release, unless it's added as an "extract"
Any ideas?
John
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
Re: HOW DO I CALCULATE ALCOHOL FROM FRUIT?
Strain some juice off the pulped fruit and measure the SG with a hydrometer. Rinse and sanitise the hydrometer and measure the PG of the fermenting beer. Assume the volume of the fruit to be all liquid (not very scientific
) and then work it out by:
Approx: PG of 20 litres of 2/3rds fermented beer is 1.020
SG of 3 litres of fruit is 1.040
ignore the 1 at the front of the gravities
Beer: 20 x .02 = 0.4
Fruit: 3 x .04 = 0.12
Add: 0.4 + 0.12 = 0.52
Total volume: 20 litres + 3 litres = 23 litres
Total gravity: 0.52 / 23 = 0.023 approx
put the 1 back in front = 1.023
when you put 3 litres of 1040 fruit into 20 litres of 1020 beer you get 23 litres at 1023
Measure the FG - say 1010?
From the point of adding the fruit you get a drop of 1023 - 1010 = 13 so use the HMRC fudge factor of 0.127 (for gravity drops between 10.5 and 17.2)
13 x 0.127 = 1.65 % ABV
Now what was the OG of the beer at the start of fermentation...? If we knew that we could get the overall ABV.

Approx: PG of 20 litres of 2/3rds fermented beer is 1.020
SG of 3 litres of fruit is 1.040
ignore the 1 at the front of the gravities
Beer: 20 x .02 = 0.4
Fruit: 3 x .04 = 0.12
Add: 0.4 + 0.12 = 0.52
Total volume: 20 litres + 3 litres = 23 litres
Total gravity: 0.52 / 23 = 0.023 approx
put the 1 back in front = 1.023
when you put 3 litres of 1040 fruit into 20 litres of 1020 beer you get 23 litres at 1023
Measure the FG - say 1010?
From the point of adding the fruit you get a drop of 1023 - 1010 = 13 so use the HMRC fudge factor of 0.127 (for gravity drops between 10.5 and 17.2)
13 x 0.127 = 1.65 % ABV
Now what was the OG of the beer at the start of fermentation...? If we knew that we could get the overall ABV.
- trucker5774
- Falling off the Barstool
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Re: HOW DO I CALCULATE ALCOHOL FROM FRUIT?
Thanks edit1now. I was trying to get my head around it. The fruit was throwing me. Assume the OG of the original brew was 1040, would you be good enough to complete the equation.....................seems a shame to have gone so far
I'm not sure if I should calculate to the FG of the whole brew or to when the fruit was added
Your help is very much appreciated.............it's not expressed by enough people when a member helps out


Your help is very much appreciated.............it's not expressed by enough people when a member helps out
John
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
Re: HOW DO I CALCULATE ALCOHOL FROM FRUIT?
I think you add the drop from OG to PG to the drop from PG to FG, so if the PG of the beer is 1020, then
OG 1040 - PG 1020 = 20
HMRC fudge factor for drops from 17.3 to 26.1 is 0.128, so
20 x 0.128 = 2.26 % ABV
add 2.26% to 1.65% from my previous post = 4.21%
If you didn't add the fruit then if the FG is 1010 then
OG 1040 - FG 1010 = 30
HMRC fudge factor for drops from 26.2 to 36.0 is 0.129, so
30 x 0.129 = 3.87% ABV
Now try it with your actual figures?
OG 1040 - PG 1020 = 20
HMRC fudge factor for drops from 17.3 to 26.1 is 0.128, so
20 x 0.128 = 2.26 % ABV
add 2.26% to 1.65% from my previous post = 4.21%
If you didn't add the fruit then if the FG is 1010 then
OG 1040 - FG 1010 = 30
HMRC fudge factor for drops from 26.2 to 36.0 is 0.129, so
30 x 0.129 = 3.87% ABV
Now try it with your actual figures?
- trucker5774
- Falling off the Barstool
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Re: HOW DO I CALCULATE ALCOHOL FROM FRUIT?
Cheers edit, thanks once again 

John
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife
Drinking/Already drunk........ Trucker's Anti-Freeze (Turbo Cider), Truckers Delight, Night Trucker, Rose wine, Truckers Hitch, Truckers Revenge, Trucker's Lay-by, Trucker's Trailer, Flower Truck, Trucker's Gearshift, Trucker's Horn, Truck Crash, Fixby Gold!
Conditioning... Doing what? Get it down your neck! ........
FV 1............
FV 2............
FV 3............
Next Brews..... Trucker's Jack Knife