2nd blackberry wine didn't turn out so great

So I made this a few years ago, and really liked it:

BLACKBERRY WINE
4 lb. blackberries
3 lb. granulated sugar
1 gallon water
Lavlin EC-1118 wine yeast and nutrient

Pick fully ripe, best quality berries. Wash thoroughly in colander, then crush in bowl, transfer to primary fermentation vessel, and add gallon of boiling water, mixing thoroughly. When lukewarn (70 degrees F.), add yeast, cover, and set in warm (70-75 degrees F.) place 4-5 days, stirring daily. Strain through very fine nylon sieve or double thickness of muslin onto sugar and nutrient. Stir well to dissolve sugar and pour into secondary fermentation vessel of dark glass (or wrap clear glass with brown paper) to shoulder, and fit airlock. Ferment excess liquor in small bottle fitted with airlock or covered with plastic wrap held by rubber band. After all foaming has ceased (6-7 days), top up with excess liquor and place in cool (60-65 degrees F.) dark place for three months. Rack, allow another two months to finish, then rack again and bottle in dark glass. Allow 6 months to age, a year to mature. [Adapted from C.J.J. Berry's 130 New Winemaking Recipes]

I used store-bought frozen blackberries with no sugar added. It finished at 1.010, and while it was really good after a year or so, it was a teeny bit too sweet for me.

In Oct. 2010 I made another batch, using fresh (then frozen, and thawed) blackberries; cut the sugar down to 2.5lbs, and used D47 instead of EC-1118.

I've been bulk again for quite awhile, and finally got around to taking FG and tasting. FG is 0.094; it tastes like rocket fuel, and it pretty acidic. I stabilized and added ~7oz of honey to backsweeten a little, and I'll let it age some more.

Any suggestions as to why this finished 16 points lower using 1/2lb less sugar and a yeast with less ABV tolerance? I'm assuming sugar content of fresh v. frozen blackberries can vary quite a bit, but I'm still surprised at the "final" result.

Thanks.

blackberry seeds are notorious for containing high amounts of bitter tannin's that can really make a wine taste acidic/astringent.

I never ferment my blackberry on the seeds after having my initial batch turn out horribly bitter. I take my berries, crush in buckets with a potato masher, then use a giant nylon bag in my fermented. dump the crushed berries in and let them soak in boiling water for 2 days (adding k-meta after cooling)

I strain this bag by suspending it from a 2x4 over the bucket and let it drip, being really careful not to squeeze and extract any tanins from the seeds/pulp.

after that I bring to volume, check for initial starting gravity, and add sugar & pectic enzymes.

24 hours later I pitch yeast.

btw.. I always use D47 now in my Blackberry wine, love it. Not sure about your final gravity but all of my blackerry batches have fermented dry to about .0996~ish I don't think I've ever had a wild/fresh berry wine that didn't ferment down to at least 1.000. I would guess that maybe the first fermentation stalled out or something?

Thanks Scott.

I assumed the first batch finished at 1.010 because I hit the yeast's tolerance. I unfortunately didn't get an OG.

I really prefer D47 and 1122B to EC-1118 and use those almost exclusively in my meads with very good results.

I'm wondering if the frozen berries were processed in some way to reduce/remove seeds compared to the fresh?

Actually I just went back in my notes and see that I used 71B-1122 on Last years batch (which I just bottled about 30 days ago, have yet to try). Prior to that it was 3 years of D47.

7/7/11 I did a 3 gallon batch, 18# blackberries. Sugar to 1.090, FG of 0.996, estimated AVB 12.31%

Maybe there was some preservative in the frozen berries that hampered yeast growth?