OG variations

I don't think I ever realized how quickly variations in your OG can take place. This past weekend I did an extract Porter recipe that should have come out with an OG of 1.060. I ended up with a temperature corrected 1.057 and considered it close enough.

Being someone who doesn't let things go when it comes to his brewing, I had to figure out why there was the discrepancy. I went back through my recipe and double checked all of the fermentation estimates for my extract, but came up with nothing.

Finally I booted up Beersmith and plugged in some numbers, including the fact that I now noticed my bucket was at about 5.25 gallons instead of 5 gallons. Lo and behold, when I put 5.25 into Beersmith it came up with an estimated OG of 1.057!

I never imagined that the extra 1/4 gallon would make THAT much of a difference, but apparently it did. And the best part? I can now let my mind rest, knowing why my OG came out the way it did.

That shouldn't be surprising - a 5% change in volume and a 5% change in gravity - you don't need Beersmith to predict that. But you point is important: unless you've measured your volume to the necessary precision, it doesn't make much sense to obsess about those last few points.