Strawberry Nectar

In a blender or food processor, puree strawberries. Squeeze grapefruit to make 1 quart juice; strain. In a large kettle, combine pureed strawberries, grapefruit juice, water and sugar. Cook, uncovered, over medium heat until temperature reaches 190F. Remove from the heat; skim off foam. Strain. Ladle hot liquid into hot jars, leaving 1/4-inch headspace. Cover with lids. Process for 15 minutes in a boiling-water bath. Serve chilled and undiluted.