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A square image shot down into an open jam jar. The jam is a brilliant purple-blue color, and there's a small wooden spoon sticking out of the jar.
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Blueberry Jam Recipe

This blueberry jam is made using the French method, contains no pectin, and yields a bright blueberry flavor tempered by mellow vanilla.
Course Breakfast
Cuisine French
Prep Time 15 minutes
Cook Time 30 minutes
Combined Fridge Time 2 days
Servings 16
Calories 145kcal
Author Jennifer Field

Ingredients

  • 2 dry pints blueberries 20 oz/567 grams/roughly 4 cups
  • 16 oz sugar 454 grams/2 slightly generous cups
  • 1.5 oz lemon juice freshly squeezed, 43 grams/3 Tablespoons
  • 0.5 oz balsamic vinegar 14 ml/1 Tablespoon
  • ½ vanilla bean split and scraped, substitute 1 teaspoon vanilla extract at the end of cooking

Instructions

Day One

  • In a medium-sized, heavy-bottomed saucepan, combine blueberries, sugar, lemon juice, balsamic vinegar, and 1/2 vanilla bean (if using).
  • Use a potato masher or similar to partially crush to berries to start releasing some juices.
  • Cover, and put the pan in the fridge overnight.
    A collage of 4 images showing the beginning stages of making blueberry jam. 1)Blueberries, sugar, lemon juice, and a split vanilla bean in a medium-sized metal pan. 2)A measuring spoon pouring some balsamic vinegar into the pan on top of the berries. 3)Smashing the berries together with the sugar and other ingredients with a meat chopper. 4)The pan of partially chopped berries in pale purple juices.

Day Two

  • Take the cover off the pot, and put it over low heat for about an hour to gradually heat it until it's nice and hot.
  • As the berries soften, mash more completely with your mashing implement of choice.
  • Bring the mixture to a high simmer. Remove from heat and cool to warm.
  • Cover, and put the pan in the fridge overnight.
    A collage of 3 images and 1 block of text. 1)Mashed berries in deep purple juice in a large saucepan. 2)The berries getting more completely mashed with a potato masher right in the pan. 3)The berries and juices bubbling on the stove. 4)Text reading: "1)Place the pan over low heat. 2)Mash the berries more completely as they heat. 3)Bring to a high simmer."

Day Three

  • Uncover, and heat over medium to medium-high heat, stirring frequently, until the mixture comes to a boil.
  • Boil, stirring almost constantly, and bring the mixture to 223F/106C.
  • Remove from heat, fish out the vanilla bean or stir in 1 teaspoon of good quality vanilla.
  • Ladle into clean jars, put the lids on, and invert until room temperature. Flip jars right-side-up again. If you don't want to "quick can," just let the jam cool, cover, and refrigerate for up to 3 months.
    A collage of 4 images. The first three show jam cooking on the stove and a blue, instant-read thermometer reading 219F, 220F, and 223F. The fourth image shows three jars of jam upside down on a countertop.

Notes

Store in the fridge for up to 3 months.
Please note again: quick canning by inverting the jars is not a USDA-approved canning method. 

Nutrition

Serving: 2T | Calories: 145kcal | Carbohydrates: 37g | Protein: 0.5g | Fat: 0.3g | Saturated Fat: 0.02g | Polyunsaturated Fat: 0.1g | Monounsaturated Fat: 0.03g | Sodium: 1mg | Potassium: 50mg | Fiber: 1g | Sugar: 34g | Vitamin A: 32IU | Vitamin C: 7mg | Calcium: 4mg | Iron: 0.2mg