Wash and hull strawberries to remove tops.

Mash strawberries and measure the fruit. You should have about 8 cups.

Add strawberries, sugar, and lemon juice to a deep, heavy-bottomed dutch oven or jam pot.

Bring the mixture to a boil over medium-high heat on the stove, stirring frequently to prevent scorching or overflows.

Boil gently over medium heat for about 45 minutes to an hour, until the jam reaches its set point. The time will vary based on the water content of your strawberries and the exact heat from your stove.

Test for set using a plate that's been chilled in the freezer, or using an instant-read thermometer. The set point of strawberry jam is 220 F at sea level, and drops by 1 degree for every 500 feet above sea level. For example, at 1,000 feet in elevation the jam will set at 218 F.

When set, ladle into prepared jars leaving 1/4 inch headspace. Seal with 2 part lids to finger tight.

If canning, process jars in a water bath canner for 10 minutes (or 15 minutes above 6,000 feet in elevation). Turn off the heat and allow the jars to sit for an additional 5 minutes before removing them with a jar lifter to cool on a towel on the counter.

Check seals after 12-24 hours and store any unsealed jars in the refrigerator for immediate use.

Properly canned and sealed jars will keep for 12-18 months on the pantry shelf. Refrigerate after opening. If not canning, this jam will keep for several weeks in the refrigerator, or 6 months in the freezer.