Stovetop Method: Put berries and lemon juice into a heavy-bottomed saucepan. Cook over low heat for about 5 to 7 minutes or until fruit has softened, stirring frequently.
Add sugar and stir over medium heat until sugar has dissolved. Increase heat to high and boil rapidly until setting point is reached, approximately 5 minutes. Stop cooking when you are happy with the consistency—either runny enough to pour over yogurt and oats or firm enough to spread on toast.
Pour into a large, warm, sterilized container. Seal and set aside to cool. Store in the fridge for up to 2 weeks or do a waterbath in Mason jars or two-part lid jars using the hot-pack method for 10 minutes for a longer shelf-life.
Strictly speaking, a jam low in sugar should contain at least 25 percent sugar and no more than 50 percent sugar to be sold as “reduced-sugar” jam.
This recipe comes from Lotta Gustafsson from Sweden. She makes small amounts of this jam at a time with fresh or frozen berries. Often this style of jam is soft set, so it is ideal for pouring. However, it can be cooked for longer to become firmer—the choice is yours.
Bear in mind that the more you boil away the water to achieve a set, the higher the concentration of added and natural sugar, so you may defeat the purpose of a low-sugar jam.
This recipe will work with any juicy berries such as raspberries, strawberries, loganberries, etc. As the jam is low in sugar, it should be stored in the fridge or waterbathed for a longer shelf-life.