What I need to know is how mush will my beer gain or lose in ABV % after bottled. I just bottled a Coopers Pilsner and my OG was 1.040 and FG 1.012 this gives me a 3.7 ABV% if my math is right whats the Plus or Minus after bottle conditioning.
ABV % after bottled
- Thread starter dentdr
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carltjones
Well-Known Member
Alcohol content may increase by 0.2% with bottle conditioning. It depends on how much sugar is added and fermented for carbonation.
The Cooper's formula-(OG-FG)/7.46 + .5 =ABV% accounts for .5% increase from the priming addition.
Two things:
1) the OG and FG in that formula actually refer to the gravity points (e.g. 1.070 --> 70 gravity points)
2) 0.5% seems like a lot added from the bottle conditioning. My calculations are in the 0.2-0.3% range for most standard carbonation levels (yes, I know there's not much absolute difference, but since we measure beer ABV to one decimal place, tenths of percents matter). You might approach 0.5% for highly carbonated beers though.
Looking at the instructions,you don't remove the first two digits. You remove the decimal point. I see what you're getting at,but it isn't done that way. I always save a couple of the latest instruction pamphlets from the can's false lid. So what you're conveying is a moot point. You subtract the Final Gravity (minus decimal point) from the Original Gravity (dito here),& devide by 7.46. Yeah,adding .5 percent for alcohol produced might be a little high. But it seems like the whole list of other formulas out there are a bit low. The point being,none of them agree with on another. There was a thread last year where someone took all of them & plugged in the same numbers. All different answers. I always wondered which one is really the closest?!
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unionrdr said:
I always figured the bottle conditioning addition to abv was a pretty straightforward calculation. If you know the weight of the sugar and the volume of beer you're adding it to, you can calculate the increase I gravity (just as if you were adding sugar to the boil kettle and wanted to calculate an OG). Assuming the priming sugar ferments completely out in the bottle, you just apply the above ABV formula. I suppose things get trickier if you use DME to prime with since it is not 100% fermentable.
And the removal of decimal point vs the gravity point method are just two ways of doing the same thing. 1070-1015 is the same as 70-15. Both give you the difference in gravity points between the OG and FG.
5 ozs of corn sugar in 5 gallons will increase the effective OG by .002. That will equate to 0.25% abv. BUT ..... you dilute it in water. If you added it in 2 pints of water you would effectively get zero difference in abv in a 1.040 beer. Adding it with 1 pint of water would result in 0.125%.
Way too small to be concerned about.
Way too small to be concerned about.
@jlem-I see what you mean by dropping the "1.0",I just like to keep things straight up in that regard so as not make things too confusing when relating experiences. But while priming calculators seem to be straight up simple,the different formulas aren't,since they all give different answers. It'd be interesting to have a lab calculate the actual ABV percent of a given brew,tyhen see which calculator comes the closest to that. Then we'd know for sure which calculator is the best to rely on. I'd love to see that happen...
