If you don’t have enough to fill the final jar, refrigerate and use within a month.

6 cups blueberries, fresh or frozen
2 T. fresh-squeezed lemon juice
l tsp. finely grated lemon zest
4-5 cups sugar, to taste
6 pint-size canning jars and lids, sterilized

Have boiling water-bath canner ready. Rinse fruit in cold water, removing any stray stems and blemished berries. Drain well. Reserve 2 cups berries. Place the rest in a food processor and pulse briefly (or mash with a potato masher). Place in a 2-quart saucepan with lemon juice and zest. Bring to a boil over high heat, reduce to a low simmer and cook 5 minutes. Press cooked berries through a fine-mesh colander using the back of a wooden spoon to push through as much pulp and juice as possible. Discard dry pulp. You should have 4 to 5 cups thick juice. Return juice to pan and add an equal amount of sugar. Bring to a boil, reduce to simmer, add 2 cups reserved whole blueberries, and cook 2 minutes. Divide syrup among prepared jars, distributing whole fruit evenly and leaving 1/2 inch of head space. Wipe any spills from lip of jars. Seal with 2-part canning lids and place in a boiling water bath that covers tops of jars by 2 inches. Boil 15 minutes. Remove jars from bath and turn upside-down for 1 minute. Turn upright and cool. Check seals. Variations: Other berries may be substituted or mixed with the blueberries. Recipe may be cut in half. You may substitute a heat-proof sweetener such as Splenda for the sugar. Syrup can also be put up in half-pint jars.