Step 1

Peel, core, and dice pears, keeping the dice quite small (you can always mash the jam later on if the pear pieces are too large).

Step 2

In a large bowl, toss the diced pears with lemon juice and sugar. Stir to coat.

Step 3

Cover bowl and store in the refrigerator for 12 to 24 hours. If you're short on time, 4 hours will suffice.

Step 4

Pour macerated pears and syrup into a large, heavy-bottomed saucepan or jam pot.

Step 5

Bring the mixture to a boil over high heat. Lower heat to medium-high and cook the pears for 10 to 15 minutes, stirring occasionally.

Step 6

When the jam has thickened, test to make sure it has reached the gel stage either with a thermometer (jam should be ~220°F/105°C) or with a cold plate.

Step 7

Decant cooked pear jam into prepared half-pint jars, leaving 14-inch headspace. Wipe jars and rims clean with a dish towel and apply two-piece canning lids until fingertip tight.

Step 8

Load jars into prepared hot water canner. Process for 10 minutes. When timer goes off, turn off heat and let the jars sit for another 5 minutes to prevent siphoning due to a sudden change in temperature.

Step 9

Transfer processed jars to a clean surface lined with a kitchen towel, leaving at least an inch of space between each jar. Let the jars come to room temperature. Check seals of each jar, moving unsealed jars to the refrigerator to be used within 1 to 2 weeks. Store sealed jars in a cool, dry place away from direct light for up to 18 months.