Wash your jars, lids, and canning tools in hot soapy water. Rinse thoroughly to remove all suds. Set aside to air dry on a clean kitchen towel.

Place the jar rack into the water bath canner, set the jars on the rack, and add water to cover the jars.

Bring the canner to a simmer (180˚F) over medium heat, warm the jars for 10 minutes, and then keep them warm until you are ready to fill them.

Rinse the strawberries well under clean running water. Remove the hulls and mash the berries. Measure 4 cups of mashed strawberries. Set aside.

Add the sugar (or honey) and 2 teaspoons Pomona's pectin powder in a small bowl. Mix well to combine and set aside.

Prepare your calcium water by combining 1/2 teaspoon calcium powder (from the small packet in the Pomona's pectin box) with 1/2 cup water in a jar with a lid. Shake well to mix.

In a large saucepan, combine the mashed strawberries, lemon juice, and 2 teaspoons of the prepared calcium water.

Bring the strawberry mixture to a boil over medium-high heat. Add the sugar mixture and stir to dissolve. Continue stirring until the jam returns to a full boil, about 1 to 2 minutes. Once it boils, remove the pan from the heat.

Spread a kitchen towel on the counter. Remove a jar from the canner using the jar lifter. Drain the water back into the canner and place on the towel.

Use your canning ladle and funnel to fill the jar leaving 1/4-inch headspace at the top.

Swirl the bubble popper through the jar to release air bubbles, and wipe the rim with a clean, damp towel.

Center a lid on the jar, and screw on a band until it is fingertip tight. Use the jar lifter to place the jar back into the canner, and repeat with the remaining jars.

Once all the jars are in the canner, adjust the water level to be two inches above the jar tops.

Cover the canner and bring it to a boil over high heat. Once the water boils vigorously, continue boiling for 10 minutes at altitudes of less than 1,000 feet. Adjust processing time for your altitude if necessary (See Notes).

When the processing time is complete, turn off the heat, and let the canner cool down and settle for about 5 minutes.

Spread a dry kitchen towel on the counter. Remove the cover by tilting the lid away from you so that steam does not burn your face.

Use the jar lifter to remove the jars from the canner and place them on the towel. Keep the jars upright, and don't tighten bands or check the seals yet. Let sit undisturbed for 12 to 24 hours to cool.

After 12 to 24 hours, check to be sure the jar lids have sealed by pushing on the center of the cover. The lid should not pop up. If the top flexes up and down, it did not seal. Refrigerate the jar and use it up within 2 weeks.

Remove the screw-on bands and wash the jars. Label, date, and store your jars in a cool, dark place. Use within 12 to 18 months for the best flavor. Refrigerate your jam once opened and consume it within 2 weeks—yields about 4 to 5 half-pint jars.