First timer - alcohol test

MeaderBaker said:

I measured my sugar content when I first pitched my yeast back in November.
I got a reading of 14 % potential alcohol. Which translates to 1.12 S.G.? Correct?

I have just finished measuring it again and got a reading of 0 for potential alcohol content. Which then translates to 1.0 S.G.

the guide then says 133*(SG-FG)
so, 133*(1.12-1.0) =
133*(.12) = 15.96 % alcohol
Did I do this right? Seems high

Mead: JAOM recipe off the forum * 5 gallon


Thanks for any help

Click to expand...

First up, let me recommend you buy a hydrometer that ONLY has SG reading on it, ABV and available sugar readings are skewed by the amount of alcohol in a batch.
Usually meads use a factor of 135 so a 1.100 has a max potential of 13.5
Beers use a factor of 128 or something, So can skew your numbers a bit.

Next: What yeast were you using? What's its ABV tolerance? - hmm perhaps JAP suggests bread yeast, so you have NFI regarding that last q.


you've used a factor of 133, as above, I usually use 135. but close enough eh...

Your discrepancy comes in your assumption that avail able sugar: 14% translates to 1.12 yet you use 133 for your next calc.
133*0.120 = 15.96%

however the beer factor is different
0.120/14% = 8.5
So the factor here is 8.5

So something's skewiff with your figures.

if 14% is right, then your OG could be 14%/133 = 105 points change. so 1.105 in total.

I hope this helps somewhat, I'm not sure if I've answered your question or just given you more to think about.

This gets easier if you will put your hydrometer readings out to 3 digits. When you say you got 1.12 is that 1.102 or 1.120?

If it was 1.120 that has a potential alcohol of nearly 16% and if it went to 1.000 then yes, you are close to 16% ABV - the 133 number works reasonably well. All these calculations are rough estimates at best.