How to Make Jam--This is a basic guide to making low-sugar refrigerator jam from any fruit. It can be frozen too. This is about as easy as it gets.
1 lb fruit (e.g., raspberries)
1/4 cup sugar
seasonings to taste
2 tbsp juice of your choice
vinegar (optional)--Joanne says a splash of balsamic is delicious!
Put 1 lb fruit (pitted & chopped if necessary) in medium saucepan over medium heat. After ~1 min, add 1/4 cup sugar (or more, or less, depending on your taste), seasonings to taste (e.g., cinnamon, nutmeg, coriander, etc), and 2 tbsp juice (and the splash of vinegar if using). Adjust heat till mix bubbles steadily, using higher heat if the mix looks too soupy, lower heat if it seems dry. Cook, stirring occasionally, till mix is thick--10 to 30 min. Cool completely & refrigerate; it will thicken more as it cools. It will keep at least a week in the fridge. Remove any whole seasonings (cinnamon sticks, hunks of ginger, stalks of lemon grass, etc) before serving. Makes about 1&1/2 cups. (recipe source)