Perhaps the flavor of the currants is affected by how well you control the temperature they cook at? If that's the case, may I suggest that you try cooking your currants in a crockpot? I use my crockpot to make my applebutter and IT NEVER BURNS IN MY CROCKPOT. The flavor and texture of my applebutter is a lot nicer than anything you can buy too. I also add some vinegar to my cooking water and that seems to help the flavor as well. Hope this helps.
Anita Clyburn In waterlogged Terre Haute, Indiana (zone 5B)