Wash the berries, pickin them over to remove any bad berries. Mash the berries and cook them gently for 10 minutes, stirring frequently. Add the sugar and cook for 15 minutes or until it is thick.
When the jellying stage is reached, the drops will run together to form a sheet. If a thermometer is used it should read 219°F, which is 7°F higher than the temperature will read in regular boiling water.
Pour the jam into sterile glasses and seal with wax.