Finally bottled my watermelon wine. It turned out really nice! I was pleasantly surprised. I'll post pics later.
A couple of things I learned:
1) Watermelon is not an acidic fruit, you will have to adjust acid content A LOT: get a pH meter. I can't remember how much acid blend I used to start my 6 gallon batch, but it was whatever was suggested in the jack Keller recipe. It wasn't nearly enough to get the pH down to a reasonable level so I used tartaric acid to get it the rest of the way so I could cold crash later if needed.
2) My batch needed to cold crash. I let it bulk age for six months, and the taste was still very off when kept at a decent pH. As this is one of my first wine attempts, I didn't know what to expect from cold crashing, but figured I had nothing to lose because it tasted awful. A ton of tartaric acid precipitated during cold crash and I was left with a nice, crisp, dry white watermelon wine. I actually really enjoy it.
3) Give it time to age: it needs it. Mine is probably still a bit young at 6 months.
4) it's not going to taste like watermelon or watermelon candy. As I said, this is my first batch, and I knew it wouldn't taste like watermelon, but 99.9% of the people I have let try the wine are expecting boons farm. Haha. Just thought I'd leave a word of warning.
5) Use a fast acting yeast if you're not an expert. I had no problems, but I didn't want to have a rancid disaster for my first batch so I played it safe.
6) I don't have my notes in front of me, but my potential alcohol reading started at somewhere near 13%. I'd tone it down closer to 11.5% if I make another batch although it's actually quite nice chilled.
7) I didn't add fruit to the secondary. I would try that next time if only for color.
All-in-all a very successful first run with (what I found out after buying 6 large watermelons) a difficult fruit. I left half dry and sweetened the last 3 gallons with 1 can Apple juice concentrate. I'm going to enjoy it for the next few years!