Add all ingredients to a large mixing bowl. Stir.
Keep at room temperature for at least two hours, up to four, to allow the flavors to mingle. Or, you can cover the bowl and store in the refrigerator overnight.
Place strawberry mixture in a large saucepan over medium-high heat. Stir frequently. As the berries soften, mash them to your desired consistency.
Taste the juice and adjust as needed. If it’s not sweet enough, add more sugar. If too sweet, add more lemon juice.
Bring to a boil and cook for 20 minutes or until the jam thickens.
Pour into sterilized jars, cover, and store in refrigerator up to one month.
Cook’s note: This only pectin in this jam is the natural pectin from the fruit. As a result, the jam remains soft and doesn’t produce a firm texture like jelly. If you want a firmer texture, add pectin and follow the directions on the package.