Thanks for the feedback.
I've resolved this question and it boils down to some basic math regarding the dilution of the concentrate. Based on the Vintner's Harvest juice that I've tested and the resulting excellent tasting wine, the brix I need to be starting with (before chaptalization) is only 3 or 3.5. This is because black currant juice is way too acidic in its natural form, similar to some grapes like Mustang. Using currant at its natural brix level is just too acidic.
When I made my original must, I diluted the concentrate using a 7:1 ratio to get to a brix of 11 thinking I would start with pure currant juice. The 40 gallons of must therefore has the high acid level that I've seen.
Instead, I needed to dilute the concentrate with more like 115 gallons of water to make 120 gallons of must (instead of 40). This would result in the TA level as follows:
Total Acid in the 5 Gallons of Concentrate:
14.2% = 142 g/L = 537.5 g/Gallon x 5 Gallons = 2687 g in the 5 gallons concentrate
TA in 120 gallons of diluted concentrate:
120 gallons = 454 L
2687 g / 454 L = 6 g/L or the desired 0.6% of TA
Also, the brix numbers make sense at this level as well when compared to the VH fruit bases as follows.
I used the Vinoelogy.com water dilution calculator (
http://vinoenology.com/calculators/c...ater-dilution/) and starting with 5 gallons of 65 brix must with a target brix of 3.5 requires the addition of 116 gallons of water. Of course, I then factor in the sugar to chaptalize back to my target brix of the must of 22.
I didn't have enough secondary space for that much, so I ended up more or less doubling the must with a water, sugar, fermaid K mixture that had an SG of 1.090 matching my original must. I'll get about 90 gallons out of the batch, which is a bit of a stretch for me. I also made several 3 gallon batches with various levels of dilution so I can see the differences in the finished wines. I'll try to remember to come back and post findings in a few months.
