Concord Grape Jam

This is part two (here’s part one) of what I did with my Concord grapes, and I wanted to get this recipe posted before Concord season is too much of a distant memory.  Eating this jam makes me wish for a jar of homemade roasted peanut butter and a loaf of fresh baked sourdough bread.  PB&J with a grown-up flair…and I’d be one happy girl.

Instead, I found some fresh rosemary bread at my local grocery store (thank you, Wegmans, for having a fantastic in-store bakery!) which was a lovely pairing with the jam.

I’ve shared a couple different jams/jellies so far on my blog (Cherry Jam, Cranberry Jam, and Rose Petal Jelly) and people always ask me if they’re difficult to make.  The answer is not at all!  However, you will most likely want to invest in a run-of-the-mill candy thermometer (I’ve seen them for less than $10 though).

All jams/jellies need the right combination of fruit, pectin, acid, and sugar to gel or set properly.  All fruit naturally contains pectin; however, some fruits have more pectin than others.  Grapes have enough pectin on their own that they don’t need additional pectin; they do however, need a little bit of added acid (in the form of lemon juice) and sugar.  (To read more about getting your jam/jelly to set properly, check out the University of Missouri’s fantastic article on this topic.)

The other point of contention for many people is how to tell when the jam is done.  There are three methods I know of for testing this:

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 in this 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!).

A Note on Measurements:  This recipe can be easily adjusted for however many grapes you want to use.  If the grapes are at their peak of ripeness, use a ratio of 1 cup of sugar and 1 teaspoon of lemon juice per 1 pound of grapes (increase the sugar as necessary if your grapes are tart, but leave the amount of lemon juice the same).

Concord Grape Jam (Adapted from Epicurious)

Yields about 5 to 6 cups 

3 lb Concord grapes (weighed after you remove the stems)*

3 cups sugar

3 teaspoons lemon juice

Slip the skins off the grapes.  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, lidded 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 above), about 30 to 35 minutes, stirring frequently.

Transfer the jam to sterile jars; the jars should be preserved through canning or stored in the refrigerator.

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