Concord Grape Jam

Sterilize 3 (1-pint) jars, along with fitting lids and rings.

Slip the skins off the grapes. To do so, hold a grape between your thumb and index finger and gently squeeze — the inside should pop right out. Transfer the skins to a food processor and pulse a few times, but do not puree; set aside.

Transfer the grape insides to a heavy-bottomed, 5-quart pot; cover the pot, bring to a simmer over medium heat, and simmer 10 minutes. Turn heat off and cool to room temperature (this will take a couple hours). Transfer the grape insides to a cheesecloth-lined sieve fitted over a bowl to catch the liquid; gently wring the cheesecloth to extract as much liquid as possible.

Transfer the liquid back to the pot, along with the processed grape skins, the sugar, and the lemon juice. Bring to a boil over high heat (uncovered), then turn heat down and simmer (uncovered) until jam is done (see one of the tests below), about 35 minutes, stirring frequently.

Transfer the jam to the sterile jars; the jars should be preserved through proper canning methods or if not, you should store them in the refrigerator.

*Wash the grapes before you de-stem them, but weigh them after.

There are three methods I know of for testing when jam is done:

1) The Temperature Test: The jam should be at 220F (this is the magic number if you’re at sea level, like me); a cheapie candy thermometer works fine here.

2) The Sheet Test: Dip a wooden spoon into the jam and hold it sideways over the pot; the jam should fall off in a sheet, or the last jam to drip off should hang off the spoon in a bulging drop but not fall. (You can see what this should look like by clicking on the related blog post.)

3) The Freezer Test: Freeze a plate, then put a little jam onto the frozen plate and put it back into the freezer for a few minutes; the jam should gel and not run.

I like to do both the Temperature Test (because it’s reliable) and the Sheet Test (because it’s fun!).

(Adapted from Epicurious.)