6 cups blueberries, picked over
3 cups sugar
1/2 lemon, zest removed in strips with a vegetable peeler
1/8 cup fresh lemon juice
1. In a large saucepan combine the blueberries and 3/4 cup water, bring the mixture to a boil, and simmer it, covered, for 10 minutes. Puree the mixture in batches in a blender or food processor and force it through a fine sieve into a bowl, discarding the solids.
2. In the pan, cleaned, combine the sugar, the zest, and 1 1/2 cups water, bring the mixture to a boil, stirring until the sugar is dissolved, and boil it, uncovered, until a candy thermometer registers 200 degrees F. Discard the zest, add the blueberry mixture, and boil the syrup, stirring, for 1 minute. Let the syrup cool, skim off any froth, and stir in the lemon juice.
3. Pour the syrup into glass jars with tight-fitting lids. The syrup keeps, covered and chilled, for 3 months. Serve the syrup warm over pancakes or ice cream.