Wash 14 8-oz canning jars, including rings and lids, in hot soapy water. Allow to dry. Place lids in a shallow dish and set aside.

Have ready a large 10-qt pot, 2/3 full of water, 4-qt saucepan, tea kettle filled 1/2 way with water, berry masher, wide mouth funnel, jar lifter, ladle or stainless 1-cup measuring cup, large measuring cup (I like to use a 4-cup), or bowl to mash berries in, large separate bowl to hold the mashed berries, and several kitchen towels.

Rinse blueberries in a large strainer.

In Pomona's Pectin package, find the calcium pack. In a lidded 8-oz jar, mix 1/2C water with 1/2 tsp of calcium powder. Mix well. This will last several months (discard if powder discolors or molds). Shake well before using. Set aside. Measure out the sugar and add 4 tsp pectin to the sugar. Mix well. Set aside. Squeeze the lemons and measure out 1/2 C of juice. Set aside.

Turn the water on to boil in the 10 qt pot and the water in the tea kettle.

In the large measuring cup (or bowl), mash the blueberries. Do this in 2 C batches, otherwise, it's hard on your hands. Transfer mashed blueberries to a large bowl. Continue mashing in 2 C batches until you've depleted almost all the 5 pints of blueberries. Start measuring out the mashed blueberries and place 8 C total in the 4-qt saucepan. Mash more blueberries if needed.

Turn the stove on to about medium high under the mashed blueberries. Add 4 tsp calcium water, 1/2 C lemon juice, and granulated sugar mixture. While the blueberries are coming to a boil, move the empty jars close to your canning area. Have your wide mouth funnel standing by.

Bring blueberry mixture to a boil, stirring frequently, and scraping the corners of the pan, making sure no sugar is sticking/clumping in the corners. Boil for about 1 minute. You want all the sugar and pectin dissolved before canning. Remove from heat.

Pour the boiling water from the tea kettle on top of the lids in the shallow pan, just until they are covered. This softens the seal for a good, strong seal on the jars.

Place the wide mouth funnel on a jar and carefully begin filling the jars, leaving about 1/4"-1/2" of space at the top of the jar. Fill all the jars, topping off the jars as the residual blueberry mixture allows. Place lids, carefully removing each one from the very hot water, and rings on the jars.

To process the jars, place them in the 10-qt boiling water in several batches. You'll need at least a few inches of water to cover the jars. If needed, add more water. Process (boil) for 10 minutes.

Wipe the jars clean and dry after removing them from the boiling water.

The jar has sealed when you hear a "pop". Test the seal by pressing the center of the lid down. If the lid can still be pressed down, the jar has not sealed. Wait for 24 hours, and if the jar still has not sealed, store in the fridge and use within two weeks.

Before storing the jars, label the lids with the type of jam and date. Jam will keep for up to a year stored in a cool, dark place.