Blueberry Grape Jam

We grow blueberries.  This year an evil fence hole gnawing groundhog and the horde of squirrels and birds that followed him thru the holes ate a good portion of our crop, but I still have plenty left for cakes, crisps, muffins and jams.   Today I made a riff on my usual blueberry jam, inspired by my recent discovery of something called Thomcord Grapes:

My new favorite fruit. Can not stop craving these!!!

My new favorite fruit. Cannot stop craving these!!!

Ay Dios mio.  If you love the flavor of native grapes but hate the thick skins, honkin’ seeds and slimy texture, then these babies are for you.  They taste like toned down Concords but have the mouthfeel of a Thompson Seedless.  God bless you, oh hybridizer of these grapes!  I knew they would pair well with blueberries, so I whipped up my first batch of jam with this year’s berries.  This jam is a little sweeter and softer-flavored than plain blueberry or blueberry-blackberry.  If you want a more “grape forward” flavor, use a higher ratio of grapes,  Just make sure you use a total of 36 oz of fruit.  Here’s what you need and how to put it together:

  • 8 oz Thomcord Grapes
  • 1 lb 12 oz blueberries, half of them slightly underripe if you are picking them yourself, frozen is fine
  • 2 cups sugar
  • 2 Tbsp. fresh lemon juice or ½ tsp. citric acid
Frozen berries are great for making jam. I like to use quite a few underripe blueberries to make a more tart jam and up the pectin count.

Frozen berries are great for making jam. I like to use quite a few underripe blueberries to make a more tart jam and up the pectin count.

In a food processor pulse the grapes a few times to very coarsely chop them.

In a food processor pulse the grapes a few times to very coarsely chop them.

Add half the blueberries and pulse a few more times, till the berries are also coarsely chopped. Do NOT puree the fruit.

Add half the blueberries and pulse a few more times, till the berries are also coarsely chopped. Do NOT puree the fruit.

In a large, wide, heavy bottomed non-reactive pan combine the fruits, sugar and lemon juice (or citric acid).

In a large, wide, heavy bottomed non-reactive pan combine the fruits, sugar and lemon juice (or citric acid).

At this point you don’t need the sugar to dissolve.  Just get everything combined and let the mixture rest 30 minutes.  After 30 minutes, lightly crush fruit with a potato masher and stir until sugar fully dissolves.

Mash fruit lightly and stir to dissolve sugar.

Mash fruit lightly and stir to dissolve sugar.  Look at all those anthocyanins!

Let the mixture macerate another 30 minutes.  Then use a spatula to stir thru the mixture to make sure all the blueberries are “popped”.

Gently mash any unpopped berries on the side of the pan - careful not to splat yourself!

Gently mash any unpopped berries on the side of the pan – careful not to splat yourself!

Let the mixture macerate for one more hour – you are giving the fruit time to release its pectin.  Using this method allows you to make jams with no added pectin and a lower amount of sugar.  Plus, for me, there is a Zen about slowly producing food, gently coaxing out all its goodness.  Good things come to those who wait!  After macerating the fruit for 2 hours total, get your canner set up and sterilize your jars and lids.  Bring the fruit to a boil over medium high, stirring occasionally (a silicon spatula is great for this task).  Once the mixture boils, turn the heat down a bit.  Cook fruit, scraping the sides and bottom of the pan every minute or so until mixture reaches the gelling point.

At first the mixture will produce a good amount of foam. I rarely skim off the foam up front - I find the majority of it dissipates as the mixture cooks. Any left at the end can be skimmed off.

At first the mixture will produce a good amount of foam. I rarely skim off the foam up front – I find the majority of it dissipates as the mixture cooks. Any left at the end can be skimmed off.

As the mixture approaches the gelling point it will darken and thicken and the foam will subside. Stir more frequently to prevent scorching your precious jam.

As the mixture approaches the gelling point it will darken and thicken and the foam will subside. Stir more frequently to prevent scorching your precious jam.

Technically speaking, the gelling point is 8 degrees above the temp at which water boils at your altitude.  If you don’t have an accurate thermometer, you can tell your jam is done when it “sheets” off a spoon.  Or you can do what is known as the plate test: before cooking jam, place a saucer in the freezer.  To test the jam, remove pot from heat and place 1 tsp. jam on plate in freezer; wait 1 minute; take plate out of freezer and lightly push jam with finger – if it shows a “skin” on top it is done, if it is runny, continue cooking jam and retest.  Once you’ve made jam a few times, you will be able to tell by looking at it in the pot if it is done.  When I suspect my jam is done, I turn off the heat, wait a minute and see if a slight skin forms on top:

When the jam has been cooked to the gelling point, it will

When the jam has been successfully cooked to the gelling point, it will “crinkle” on the surface as it cools.

When jam tests done, ladle hot jam into sterilized canning jars, leaving ½” headspace (you can use 4 oz, 8 oz or 12 oz jars).  I recently upgraded to this Kilner funnel and man, I love it!  It is heavy enough to stay put in the jar and wide enough to really be of use.

Even if you are not a canner, this funnel has a jillion uses.

Even if you are not a canner, this Kilner funnel has a jillion uses.

Wipe rims, place new lids on top and seal with bands.  Process jars 10 minutes in boiling water bath.  Turn off heat, remove lid from canner and allow jars to cool 5 minutes before removing them from water.  Makes around 5 half-pints. Enjoy!

Advertisements
Post a comment or leave a trackback: Trackback URL.

Comment on this Post

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: