Choose very ripe strawberries. Put into a sieve, wash in cold water, drain very well. Hull them. If too large, halve. Macerate overnight with the sugar in a bowl. Pour the contents of the bowl into a preserving pan, add the lemon juice and the chosen setting agent, according to the instructions. Bring to a boil, boil for 5 minutes or for the time indicated. Then sieve the pan╒s contents. Put the juice collected over the heat. Bring to a boil, boil for 5 minutes, put in the strawberries again. Repeat this cooking operation 3 times all in all. Skim. Remove the pan from the heat, start filling the jars little by little to prevent the strawberries from floating on the surface if you pour too fast. Leave as little space as possible between the jam and the lids; the less air there is in the jar, the longer the jam keeps. If you want to keep perfectly, cover the cold jam with a wax paper, soaked in paraffin oil and drained, before covering with the lid.
