This homemade blackberry jam captures the bright, tart-sweet flavor of fresh berries with a soft set that's perfect for spreading on toast or dolloping onto scones.
10 min prep
20 min cook
64 servings
50 kcal/serving
Ingredients
6 cups fresh or frozen blackberries
4 cups granulated sugar
1/4 cup fresh lemon juice (about 2 lemons)
1 packet (1.75 oz) powdered fruit pectin
Instructions
Place a small plate in the freezer to test the set later.
In a large pot, combine blackberries and lemon juice. Crush berries with a potato masher to desired consistency.
Stir in pectin until dissolved. Bring to a full rolling boil over high heat, stirring constantly.
Add sugar all at once, stirring until dissolved. Return to a full rolling boil and boil for exactly 1 minute, stirring constantly.
Remove from heat. Skim off any foam. Test the set: drop a spoonful of jam onto the cold plate; if it wrinkles when pushed with a finger, it's ready. If not, boil another 30 seconds and test again.
Ladle hot jam into sterilized jars, leaving 1/4-inch headspace. Wipe rims, apply lids and bands, and process in a boiling water bath for 10 minutes (adjust for altitude).
Cool jars undisturbed for 24 hours. Check seals; refrigerate any unsealed jars and use within 3 weeks.
Tips
For seedless jam, press the cooked berry mixture through a fine-mesh sieve before adding sugar.
Store sealed jars in a cool, dark place for up to 1 year. Once opened, refrigerate and use within 3 weeks.
If using frozen blackberries, do not thaw before cooking.