Confusion in calculating my ABV

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grovedude

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Totally newbie question here - and I've even tried searching for the answer but nothing has done the trick. (Maybe I am dense?)

I am trying to calculate my % ABV, and failing. So I took photos in the hope that someone here could teach me.

The photo (which I am going to try to attach here) shows before and after.

Before = minutes before I pitched the yeast
After = 7 days later when I racked it

This is an experimental brew- I am using a Chimay-style of recipe, but instead of Belgian Candy Sugar, I am using agave syrup (not nectar, I actually got it from a friend's tequila distillery in Mexico and brought it home with me. It's the stuff they make tequila out of, direct from the oven.)

Can anyone help me? I think, based on the readings, my experiment may have produced a beer that is extremely low in alcohol.

before-after.jpg
 
1.072 and 1.030. I use Rooftopbrew website and enter those numbers in their ABV calculator. You probably haven't reached final gravity yet though as its only fermented a week.
 
It's still bubbling in the secondary now, so I wonder how high it is likely to go. Thanks for helping me out - I think I see what you're reading now.
 
You certainly didn't make a weak beer. Your final grav may get down below 1.020. You would have a 7 plus ABV.
Just rough estimates.
 
It's still bubbling in the secondary now, so I wonder how high it is likely to go. Thanks for helping me out - I think I see what you're reading now.

It's more of a how low will it go. Not knowing what you are looking for I'm guessing you are wanting a beer to finish around 1.020 which is 7.1%
 
A simple rule of thumb is to use this equation:

ABV% = (OG - FG) * 131

So in your case:

ABV% = (1.072 - 1.030) * 131 = 5.5


There are other formulas out there, and calculating the actual ABV can actually get quite complicated if you look into the details, but that approximation works well for most beers.
 
I like how different people read the same scale 3 different ways while everyone read the 1.030 current. I have to ask weirdboy, how did you come up with seeing a 1.068?

Sorry, it was 1.072...I meant to change that number in my other post. I guess I ought to do that so as not to cause more confusion.
 
Next time don't rack your beer until you've reached FG. Give it at least two weeks in primary and then take a couple gravity readings on two seperate days to make sure your beer is at FG.
 
Regarding the pictures you posted....The first set is the scale for Specific Gravity... SG. It is the one almost everyone refers to when talking beer. The second set is basically useless for beer and is used more for wine or mead, where the potential to reach a final reading of 1.000 or lower. It is "potential" alchohol. We never use that one for beer. The 3rd set of pictures is for a scale called Brix or Plato. You will learn about that one later, ignore it for now:).
 
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