How to make it:
You'll need a large dutch oven to cook down the jam. Set aside.

Rinse and cut off the stems of the strawberries. Cut in half and place in a shallow bowl. When you have enough that covers the bottom (one layer), smash with a potato masher. Measure out 1+1/3 cups and keep track! You want to have ten of those measurements transferred into a large dutch oven. Stop when you've reached 13+1/3 cups smashed strawberries.

I like a smoother jam, so I ran my immersion blender through it just a little bit, but that’s completely preference.

(If you're making a smaller batch, follow the directions on the box.)

Place over high heat.

Add in 15 Tbsp of pectin (which is just about under 1 cup) and the juice of one lemon. Bring to a boil, stirring occasionally.

Once you have a hard boil going, slowly add in 9 cups of sugar, stirring in between. Bring back to a boil, then remove from the heat. The top will start to foam, skim that off with a spoon or strainer and discard.

Place hot, sterilized jars onto a baking sheet to contain the mess. Ladle jam into each jar, leaving 1/4 inch head space. Use a moistened paper towel to wipe any jam or brine from the rims of the jars. Any matter left on the rim could compromise the seal of the lid, and cause spoilage.

Screw the rings onto your jars, but only until finger-tight. In other words, turn them just until they give resistance, and then give a little more. If you screw the rings on too tightly, air cannot escape, and the lids may not seal properly.

Water Bath Method:
Fill a large pot with water and bring to a low boil. Lower each jar directly into boiling water with canning tongs. Once all the jars are in the pot, they should be submerged by about 1” of water. If necessary, add more boiling water from your kettle. When your processing time is up accordingly to the pectin directions, turn off the heat. I boiled 9 jars at a time inside a large 12 qt stock pot for about 5-7 minutes, testing the lid "buttons" with the tongs. You can watch the air bubbles escape while submerged, which is exactly what you want to see.

Using your canning tongs, carefully lift each jar vertically up and out of the pot, making sure not to slosh the contents, which could interfere with the seal of the lid.

Place each jar on a cooling rack or towel. Do not set jars directly on a counter or other cool surface as the temperature differential can shock the jar and cause breakage; also make sure the jars are not in a place with a lot of cold airflow. Allow the jars to sit for at least 12 hours undisturbed at room temperature.

If any lids do not seal, reprocess using the same method, or store in the refrigerator and simply consume. Store sealed jars in a cool, dark place for up to a year.

So cool, right?! Enjoy your delicious homemade strawberry jam!

Notes: There are different types of fruit pectin, which require different amounts of ingredients. I have always used low sugar SURE-JELL and even used one cup less sugar than directed.