Step 1

Prepare the berries. Cut the berries into large chunks, discarding any heavily bruised sections. Place a few clean metal spoons in the freezer.

Step 2

Combine the fruit and sugar in a saucepan. Place the fruit, sugar, lemon, and salt in a 2- to 3-quart heavy-bottomed saucepan over medium heat and mash the fruit a little with a potato masher or large fork into a chunky texture.

Step 3

Cook the fruit and sugar. Bring the mixture up to a boil, stirring frequently. Continue to boil while keeping an eye on it, still stirring frequently, until the fruit is jammy and thick, about 20 minutes.

Step 4

Begin checking the fruit for doneness. Start checking to see if the jam is set. Remove a spoon from the freezer and dribble several drops of the jam onto the spoon. Wait a few seconds, and then run a finger through the jam. If it leaves a distinct track in the jam, it is done. If it runs back in on itself, keep cooking the jam and test again a few minutes later.

Step 5

Cool the jam and move it to two jars. Turn off the heat and carefully transfer the jam into 2 clean (8-ounce) glass jars. Cool to room temperature. Seal, label with the fruit and the date, and store it in the refrigerator for up to 3 weeks.