Bring to a boil over medium-high heat, making sure to stir constantly (it’s very important that you watch this carefully and whisk/stir throughout the process).

Once a boil is reached, add the lemon juice and whisk well. Boil for 1 minute, stirring constantly.

Reduce the heat to low and add the raspberries, folding them in gently with a wooden spoon or silicone spatula.

Increase the heat to medium-high heat and bring to a boil once again, gently stirring the raspberries to prevent clumping or scorching.

Once a boil is reached, remove from the heat.

Remove a jar from the hot water (empty any water remaining in the jar) and turn the heat back to “high” to begin the boiling process for the canner once again.

Fit the jar with a canning funnel, and ladle the pie filling into the jar, leaving a generous 1” headspace (up to 1 ½ inches if using a regular mouth jar****). Remove any air bubbles with a clean butter knife or debubbler tool. Adjust headspace if necessary.

Wipe the rim of the jar with a clean, damp kitchen towel (or paper towels). Using a magnetic lid lifter, center a warm lid on the jar, then secure a canning ring until it is fingertip tight.

Place the filled jar in the canner, then repeat with the remaining jars until all of the pie filling has been used up. You should get 5-6 pints.

Place the lid on the canner and bring it back up to a rolling boil over high heat.

Once a boil has been reached, process for 30 minutes.

When the 30 minutes are up, turn off the heat and remove the canner from the element. Remove the lid, and wait 5 minutes.

After the 5 minutes are up, remove the jars with a jar lifter and place them on a thick kitchen towel. Leave them completely undisturbed for 24 hours.

After 24 hours, check the seals and remove the canning rings. Wipe down the jars and label them. Any jars that have not been sealed should be moved to the fridge to be eaten right away.