Found on Canning Craze
2 pounds fresh strawberries, hulled
4 cups white sugar
1/4 cup lemon juice
In a wide bowl, crush strawberries in batches until you have 4 cups of mashed berry. In a heavy bottomed saucepan, mix together the strawberries, sugar, and lemon juice. Stir over low heat until the sugar is dissolved. Increase heat to high, and bring the mixture to a full rolling boil. Boil, stirring often, until the mixture reaches 220 degrees F (105 degrees C).
Transfer to hot sterile jars, leaving 1/4 to 1/2 inch headspace, and seal.
Process in a water bath for 10 minutes.
To test for jelling: Place three plates in a freezer... after about 10 minutes of boiling place a tsp of the liquid of the jam onto the cold plate. Return to freezer for a minute. Run your finger through the jam on the plate... if it doesn't try to run back together (if you can make a line through it with your finger) it's ready to be canned!