- Candy or meat thermometer
- Cooking scale
This recipe uses half the weight in sugar as in blueberries. For example, if you are using a pound of blueberries, then you would use half a pound of sugar.
Place the blueberries in a stainless steel saucepan, and turn the heat to medium. Stir occasionally. When the berries juicy, add the sugar and stir a lot to combine it. Turn up the heat and bring the mixture to a boil. Reduce the heat to bring mixture to a low boil; partially cover. Let the jam simmer for about 20 minutes stirring occasionally. Careful when you stir so that the jam splatters don’t get you. When the temperature hits 220 F you have jam! Remove from heat and let cool a bit, then transfer to a clean pint jar.
Cooking tip: If you don’t have a thermometer handy, you can do the cold plate trick to see when the berries jell: after about 20 minutes place a small amount of boiling jelly on a plate, and put it in the freezer for a minute or so. If the mixture gels, it’s jam!