2 quarts fresh strawberries, hulled and roughly chopped (about 8 cups)
5 cups granulated sugar, divided
1 vanilla bean, split and seeded
Zest and juice of 2 lemons
6 ounces (2 packets) liquid pectin
Combine the strawberries, 1 cup of sugar and vanilla bean seeds and pods in a large, nonreactive bowl. Allow to sit at room temperature for 15-30 minutes to macerate, then cover and refrigerate overnight.
When you’re ready to make the jam, prepare a boiling water bath and 4 pint jars. Place the lids in a small saucepan of barely simmering water. (See my water bath canning tutorial for more guidance.)
Place the strawberries in a large, nonreactive pot (I used my Dutch oven). Add the remaining 4 cups of sugar and lemon zest and juice and stir to combine. Bring to a boil over high heat and be prepared for the mixture to foam like crazy (see my Instagram video to get an idea). Cook over high heat for 15-20 minutes, until the mixture takes on a thick, syrupy consistency.
Remove the vanilla bean pod from the pot. Use an immersion blender to ever so slightly purée some of the fruit, or transfer about about a third of the mixture to a blender to purée and then return to the pot. Stir in the pectin and bring to a rolling boil. Insert a candy thermometer and let the jam boil vigorously, stirring frequently, until it reaches 220ºF, and allow it to stay there for about 2 minutes. You can also gauge the jam’s set by letting it drip from the side of a spoon. If it drips in sheets, then you’re good to go.
Remove the pot from the heat and ladle your jam into the prepared jars, leaving ½-inch of headspace. Wipe the rims, apply lids and rings and process in a boiling water bath for 10 minutes.