- Nov 18, 2018
- Reaction score
- Sherwood Park, Alberta, Canada
Well, I may get labelled a nerd, but I wholeheartedly take that as a compliment. I made a triple berry DB last year and had the same questions as you. Adding the fruit should drop the ABV, not raise it. I weighed my berries before putting them in the mesh bag, and took the quoted amount of sugar from the nutritional information on the frozen berry bag. I weighed the mesh bag after fermentation and found that about 90% of the weight made it into the must, and assumed most of that was liquid. Obviously some of it would be pulp that drops out as lees, but I have no way to determine how much that might be.@BernardSmith and @sour_grapes, thanks so much. I never thought about SG as you've described it, but I get it. I started off at 6 gallons without the fruit. At 6 gallons without the fruit I had a starting 1.103 SG reading.
How much volume did the juice add? I have no idea! I can only say that I added 11lbs of berries and that I was surprised at how much DB I had left in my primary when I racked off 6 gallons of it to my carboy at the end of the ferment. All that extra liquid had to have been because of the added fruit juice from the berries.
I guess not knowing the added volume doesn't get me closer to the answer, does it?
Sooo... to spare everyone the boring details of my calculations, I can concur with what @sour_grapes and @BernardSmith have "guesstimated". If your triple-berry is the same as the Canada Costco triple-berry, and if the blueberries have the same amount of sugar and water content, your berries would have added 1.15 gallons of juice at 1.035 SG. From my calculations and estimations, that would have dropped your effective initial SG from 1.103 to 1.092, and your final ABV would be 13.4%, exactly what Sour_Grapes estimated.
This brings up a good point about the "presser method" used for Dragon Blood: it makes it very difficult to determine the final ABV. The liquid and the sugar get released into the must gradually, over several days. I squeezed the heck out of my berries on day #1. My SG dropped from 1.110 to 1.108. It should have dropped more than 5 times that much. And on day #2, the SG actually went back up to 1.110 after squeezing the bag.