Monday, June 27, 2011

Forgetting to measure the final gravity

Getting the statistic about the beer that you brewed is important for the serious homebrewing, but it may be forgotten by some destruction sometimes.

I bottled my hoppy wheat ale and hoppy wit today.

I forgot to measure the final gravity, but it was too late as I already put the priming sugar into the beer in the bottling bucket.

However, I needed to find the gravity of the beer after fermentation to find out the ABV.

Here is the answer I came up with by going back to the high school chemistry experiment.

The difference of the boiling point between different types of fluid.

Boiling point of Ethanol is 78℃, hence the Ethanol contained beverage, Beer has lower boiling point than the pure water.

Here is the graph I referred to find out the ratio of the ethanol in the beer after it boiled at 95℃.

This is really helpful, but not as accurate as using the gravity before and after fermentation.


  1. Yeah there's been a couple of times I've forgotten the OG, but never the FG.

  2. I was too excited about siphoning the beer into the keg... if I may give an excuse.