Our beer was not performing up to (our) standards. Bubbling was minimal. The cat had knocked out the airlock and we were concerned the yeast was not working as it should. We did a reading of the specific gravity and it had gone from 1.057 to 1.029. Not too bad, but not great. So, our friend Mark came to save the day.
We added some yeast exciter, gave it a good stir and stuck the lid back on.
Then, we tried to do some math. Apparently, you can figure out the alcohol content of a beer with the following equation. Original Gravity (OG) is that first reading you take, Terminal Gravity (TG) is the reading you take when you move it to the secondary fermenter or keg (or bottles).
% Alcohol = ((1.05 x (OG – TG)) / TG) / 0.79
we wanted to figure out what TG we would need to get a % alcohol of 6.
so then I tried to do some algebra.
I think I did great until I got to X + X0.045 = 0.0485. I couldn’t for the life of me remember how to deal with that, and then I started making stuff up. So then we decided to go back to the original equation and make a guess. I suggested (given what I got to at the end of the algebra) that it would be 1.011. That got us 6% within two decimal points, and I scared the beejesus out of Mark and Amos.
So, all in all a good night. The beer isn’t necessarily ruined and neither is my brain (at least not completely).
If you can tell me how to get that algebra equation right please do, I’m going bonkers.