Tart up your blueberries with red currants. They’re in season at the same time, so are natural companions. I find big blowsy blueberries to be a little cloying so I like to cut their flavor and texture by adding something piquant to them. Lemon zest and lemon juice for sure, but in this jam, tart red currants do the trick. They not only impart the requisite sour to offset the sweet, but also contribute to the gelling quality of the jam and thus diminish the amount of sugar. The tough skins of both berries disappear into a smooth and silky consistency that spreads easily over your morning toast.
4 c blueberries (1½ lb)
1¼ – 1½ c sugar (depending on tartness of the berries)
Dry half-pint red currants (1 c of berries, approximately 6 oz), de-stemmed
1 c water
Peel and juice the lemon, reserving the seeds. Place the blueberries, sugar and lemon juice in a bowl and stir to combine. Tie the lemon peel and seeds in a piece of cheesecloth or small muslin spice sack and add it to the blueberries. Let the fruit macerate for a couple of hours, or overnight, stirring occasionally to dissolve the sugar.
Place the currants in a small saucepan with the water and bring them to a boil, cooking for several minutes until the berries burst. Set the mixture aside to cool and then push it through a sieve to remove the seeds. Add the currant puree to the blueberries.
If you are canning the jam, prepare the jars and set a saucer in the freezer for testing the gel.
Place the blueberry-currant mixture in a wide saucepan and bring it to a boil, stirring. Cook until the jam tests for gel (when a small drop of the frozen saucer wrinkles to the touch). This takes 7-10 minutes.
Ladle into the prepared warm jars and process using a water bath canning method for 10 minutes after the water returns to a boil. When complete, turn off the heat, remove the canner lid and let sit for 5 minutes before removing the jars to a counter to cool undisturbed.