Wash, hull, and crush 4 cups fresh strawberries
Combine strawberries with 4 cups sugar and 1/4 cup lemon juice in a large pot
Let the mixture sit for 30 minutes
Bring to a boil over medium-high heat, stirring frequently
Boil until the mixture reaches jam setting point, about 220°F or until it thickens
Skim off any foam from the surface
Sterilize jars and lids
Ladle the hot preserves into the jars, leaving 1/4 inch headspace
Wipe jar rims clean and seal with lids
Process the jars in a boiling water bath for 10 minutes
Remove jars and let them cool completely
Check that the lids have sealed before storing