Wash, stem and crush strawberries. Slice and grind fruit through food processor. Measure 3 1/4 level cups crushed strawberries and 1/4 cup lemon juice in a 4 quart kettle and stir well. Sift in slowly 1 package fruit pectin, stirring vigorously. Set aside 30 minutes, stirring occasionally. Add 1 cup light corn syrup. Mix well.
Measure 4 1/2 level cups sugar into dry bowl. Gradually stir this into the crushed fruit. Warm to 100 degrees, no hotter, to hasten sugar dissolving. Store in jelly glasses or suitable freezer containers with tight lids. Store in freezer, unless jam will be used in 2 to 3 weeks, then store in refrigerator. Makes 7 cups.