redcurrant jelly
A clear, set jelly made from redcurrant juice, sweet with a distinct tartness.
In German-speaking countries and Britain, redcurrant jelly usually sits with the jams in any supermarket. In North America it is less common and more often found in well-stocked grocers, delicatessens or by mail order.
Substitute:
Lingonberry or cranberry jelly matches the fruity tartness well but tastes sharper and slightly more bitter. Apple jelly with a squeeze of lemon is milder and less fruity.