Step 1

Place washed and hulled strawberries with sugar and lemon juice in a large roasting pan and let marinate covered overnight.

Step 2

Next day, preheat the oven to 340°F. Bake for 2 hours uncovered, stirring occasionally.

Step 3

Using a hand blender, mash softened strawberries until smooth. Stir in dissolved pectin.

Step 4

Place the roasting pan back into the oven and bake again for another hour uncovered.

Step 5

If the jam has not thickened to your liking, transfer the mixture to a large pot and bring to a boil on the stovetop. Let cook on medium-high heat for about 30 minutes until thickened. Stir often to keep from burning on the bottom.

Step 6

Transfer to hot sterile jars, leaving 1/4 to 1/2 inch headspace, clean rims of jars and seal with sterilized lids.

Step 7

Place jars upright in a large deep dish baking pan and place in the oven for another 30 minutes at 210°F.