Step 1: Wash and hull the strawberries, then crush them one layer at a time using a potato masher to reach the 5-cup measurement for your strawberry jam recipe canning.
Step 2: Prepare your canner, jars, and lids by sterilizing them in boiling water to ensure a safe strawberry jam recipe canning environment.
Step 3: Combine the crushed strawberries, lemon juice, and pectin in a large, heavy-bottomed pot, stirring well to incorporate.
Step 4: Bring the mixture to a full rolling boil over high heat, stirring constantly to prevent scorching during the strawberry jam recipe canning process.
Step 5: Stir in the sugar all at once and return the mixture to a full rolling boil; boil hard for exactly 1 minute, stirring constantly.
Step 6: Remove from heat and skim off any foam. Ladle the hot jam into the prepared jars, leaving 1/4 inch of headspace, which is vital for proper strawberry jam recipe canning.
Step 7: Wipe the rims, apply the lids and bands, and process in a boiling water bath for 10 minutes to complete the strawberry jam recipe canning procedure.