How to cook
Clean and wash the strawberries.
In the container in which you will be boiling the strawberries, arrange a layer of strawberries and a layer of sugar. Leave them overnight.
The next day, put them to boil with a glass of water. Once the syrup thickens, add the citric acid. After 5 min, remove the jam from the heat, shake to separate the foam and unstick the strawberries from one another.
Pour into jars and close while hot. Turn them with the caps down, to create a vacuum.