To make delicious homemade strawberry jam, start by cleaning and hulling about 2 quarts of fresh strawberries. Hulling means removing the stems, leaves, and any underripe or bad spots. You can easily crush the strawberries using a potato masher or a food processor. Measure out exactly 5 cups of crushed strawberries for the recipe.
Next, place the 5 cups of crushed strawberries in a large heavy-bottomed pot. Stir in a box of Sure-Jell and bring the mixture to a boil, stirring regularly. Once boiling, add 7 cups of granulated sugar and continue to stir. Bring the mixture to a full rolling boil for 1 minute, making sure not to let it burn.
Once the jam has reached its desired consistency, remove the pot from the heat and ladle the hot strawberry mixture into prepared jars. Prepared jars should be washed, rinsed, and heated to 200 degrees to prevent cracking. Fill each jar with jam, leaving 1-2 inches of headspace at the top. Wipe the rim and threads of each jar then attach sanitized lids and rings.
Process the filled jars in a hot water bath for 10 minutes. Place the jars on a rack in a canning pot with at least 2 inches of water above the jars. Cover the pot and boil for 10 minutes. Carefully remove the hot jars from