Need help calculating priming sugar after boosting gravity with vodka or liqueur

General Homebrew Discussion
1

I deleted some ingredients in a 5-gal extract recipe without recalculating gravity and now have a mild in the fermenter with an OG of 1.037.

I’m thinking about adding either some vodka and/or perhaps a coffee liqueur prior to bottling, but I’m unsure how to adjust the priming sugar to reflect what those spirits will contribute.

Randy Mosher’s Radical Brewing has an example with Frangelico on page 155, but I don’t understand where one of the numbers is derived from.  It gives 21.6 P for 56 proof Frangelico, but where does the 21.6 come from?

Thanks in advance for your help.

2

Frangelico has sugar in it, vodka does not. Research what ever you decide to add to determine the amount of sugar you will be adding.

3

Thanks. Then adding vodka would not affect priming sugar calculations,. but would boost the gravity of the beer.

4

I assume that distilled alcohol with no added sugar would not boost gravity (in fact it would result in a lower gravity reading) but it would effect abv as its adding more alcohol.