1. Rinse fresh blueberries to keep dry.
2. Add rock sugar, the amount of rock sugar is up to your taste.
3. Crush part of the blueberries to measure at least the juice, and simmer for ten minutes on high heat and turn to low heat.
4. Stir and simmer on low heat.
5. The container is sterilized by high temperature.
6. Boil for more than one hour until it becomes viscous.
7. Let cool and bottle.
Tips:Boil blueberry jam without adding water, and completely use blueberry juice. When you start to boil, you must mash it to get some juice before turning on the fire. After starting the fire, the fire is high for ten minutes, and then the fire is turned to a low heat and the mixture is kept stirring continuously.
It is better to use a steamer than a frying spoon, and it can save juice from going out.
Rock sugar is thicker than white sugar.
It can be stored frozen after being allowed to cool, and it can be thawed when eating. Small quantities can be kept refrigerated.
