Perfect for jam! Are you sure they are ripe? Maybe dewberries just taste sour to you? Man nothing is even breaking dormancy here, and you have ripe berries?

How many (fruiting) years have you grown them? Berries just turning black does not mean ripe.

this is the first fruiting year. i'll let 'em ripen more and see how that works out. they sure looked ready to pick.
thanks

I heard that once the fruit looks no longer shiny, it is ready. I'm new to blackberries. I will be planting them this year, as soon as spring arrives! Well as soon as the nurseries send them. Good luck, yeah it probably isn't ripe yet, and it could be that the 1st year, the plant is new and all. So even if they were ripe, I would give it another year. It seems hot weather produces sweet fruit, and it has been a cool spring. I also noticed from comments of others that in general no matter what fruit, early varieties are a challenge as far as taste, and that mid-season maturing varieties seem to taste best. But this is not always true. Chester is late maturing and others do taste better. But the plant has it's own merits, hardy, heavy producer, disease resistance. So appears to be a worthy plant all the same.

Keep a close eye on those dewberries, and when you can spot a couple of berries fallen on the ground, many of the softer black berries will be ripe. Or shake the vine; ripest berries will fall off.