Turn summer's bounty into CERTO® Strawberry Jam in under an hour! Follow our CERTO® Strawberry Jam recipe to make tasty jam with just four ingredients. Bring boiling-water canner, half-full with water, to simmer. Wash jars and screw bands in hot, soapy water; rinse with warm water. Pour boiling water over flat lids in saucepan off the heat.