In a stockpot, combine the strawberries, sugar, vinegar and salt. Bring to a rolling boil, and cook stirring frequently for 15 to 20 minutes, or until the temperature of the mixture has reached 220 degrees F (105 degrees C).
Transfer the mixture to hot sterile jars, leaving 1/2 inch headspace, and seal. Process jars for 10 minutes in a water bath. Refrigerate jam once the seal is broken.
