- In a blender, purée 2 cups of the strawberries until smooth. Set aside the coulis.
- In a large saucepan, combine the remaining strawberries, the sugar and lemon juice. With a potato masher, roughly crush the strawberries.
- Add the strawberry coulis and bring to a boil over medium heat, stirring frequently while scraping the sides and bottom of the saucepan. Let simmer over medium-low heat for about 15 minutes, or until a candy thermometer reads 224°F (106°C) or the jam passes the Plate Test (see below). Skim carefully while cooking.
- Pour into airtight containers. Let cool, then refrigerate. The jam will keep for several weeks in the fridge or 6 months in the freezer. You can also pour the jam into hot sterilized jars, then submerge the jars in boiling water for 10 minutes. This added step will ensure a long shelf life.
The plate test
Place 2 or 3 small plates in the freezer before you begin cooking. Once the jam is cooked, pour a spoonful onto a chilled plate and place it in the fridge for about 2 minutes. Tilt the plate. If the jam is thick and it runs slowly, it’s ready.