Unexpected ABV

Northern Brewer General
1

Hello Everyone,

Yesterday when bottling an Apricot Blonde, I took a gravity reading which resulted in an unexpectedly high ABV percentage. The OG for the beer was 14 °P (1.057) and the FG reading came in at 6 °P (or 1.003 after running numbers through a calculator). This resulted in an ABV over 7%, which is quite a bit higher than I was expecting. The only missing piece of information is that several days into primary fermentation, I added a can (3 lbs.) of apricot puree, which was not accounted for in the OG reading. The recipe I used was NB’s Dry Dock clone, and when I referenced DD’s website I saw that they list the ABV at ~5%, which I’m guessing is what the recipe was calibrated for and is what I was hoping to achieve. Could it be that the fruit puree addition has skewed the ABV estimate based on the OG/FG readings, or did I just wind up with an unusually strong beer?

FWIW, I’ve had good luck using BeerSmith to calculate my OG/FG readings (I’ve dialed it in to within a point or two in most cases), and for this beer the estimated FG was 1.011, but this did not include the fruit addition because I didn’t know how to enter the information for the puree. This is what is leading me to believe that there is something else going on here – this is my first time brewing with puree.

Any insight appreciated!

2

The simple sugars in the fruit would add to the OG which will then change your calculated FG, plus they will ferment out completely, resulting in a lower FG than if you hadn’t added them. (One lb of sugar lowers the FG by ~0.002.)

3

If anything I think it would be even stronger because of the fruit. You measured the sugars, then added more and measured again later. Whatever sugars came from the fruit would have fermented out as well making it stronger than measured.

4

Thanks to both of you – so, bottom line, the ABV estimate here can be trusted or might even be a little low since the OG was bumped up a bit by the fruit addition?

Edit: Oops - misread the last post; it looks like the numbers are to be believed!