Capture the sweet flavor of ripe summer blueberries with my Easy Blueberry Jam Recipe. You only need 3 simple ingredients, one pot, and a total of 30 minutes to make a batch.
Wash the blueberries and dry them well. Add them to a large pot (at least 5 quarts), along with the sugar and lemon juice.
Place the pot over medium heat. Cook the blueberries, stirring frequently, for 5 to 7 minutes, until they release their juices and the sugar dissolves. (Scrape the sides of the pot frequently). Mash about half of the blueberries with a potato masher.
Attach a candy thermometer to the side of the pot. Bring the mixture to a boil over medium-high heat, stirring frequently.
Gently boil the jam for 15 to 20 minutes, stirring frequently, until the jam is thick and syrupy and the temperature reaches 218 to 220°F. (Stir more regularly during the last 10 minutes of cooking. As the jam thickens, it is more likely to scorch on the bottom or sides of the pot. Adjust the heat between medium and medium-high to keep the jam at a strong simmer, moving closer to 220°F, but not boiling too rapidly.)
When it’s done, pour the hot jam into sterilized mason jars and chill overnight. Store in the refrigerator or freezer, or follow the directions provided by the canning jar manufacturer for how to sterilize, process and seal your jam jars safely.
Notes
It's important to use a pot at least 5 quarts in size to make the jam safely. Using a smaller pot for this amount of fruit could cause the hot, syrupy jam to bubble up and possibly over the sides of the pot. Stirring the jam with a long-handled spoon or spatula is also helpful and will keep you a safe distance from the bubbling mixture.
Whether you store the jam in glass jars in the refrigerator or process it for long-term storage, I recommend sterilizing the jars first. Bring a large pot of water to a boil. Reduce the heat to a simmer and submerge the jars. Let them sit in the barely simmering water for about 15 minutes. Drain and cool before using.