Prepare water bath canner according to manufacturer instructions. You will need enough simmering water in canner to completely cover jars once placed on rack.

You will also want to simmer the canning jars in water on rack in canner to prepare them for adding hot fruit. This will prevent jars from cracking once hot fruit is added. You also need to prepare the jar flat lids and screwbands according to package instructions.

Bring granulated sugar and water to a boil on medium high heat until sugar has dissolved. Reduce heat to LOW, and keep syrup warm until ready to use. Do NOT let the syrup boil down.

Peel, core, and half or slice pears.  Treat with Fruit Fresh OR place in large bowl with 1/4 cup salt dissolved in 6 cups water. If using salt/water method, keep pears submerged until ready to drain, rinse and pack jars.

Once pears (halves or slices) have been rinsed free of salt, place them into syrup mixture (single layer at a time). Heat pears through (about 5 minutes). This will need to be done in batches.

Remove hot jars from canner. Drain. Ladle pears into hot jars, through a canning funnel. If using pear halves, layer them cavity side down into the jar, overlapping layers. If canning pear slices, pack them into jars. Leave about 1/2 an inch or so from the top of the jar. Ladle hot syrup into each jar. Using a canning funnel will help this be less messy! The pears need to be covered with syrup. Make sure to leave 1/2 inch headspace in each jar. Use a plastic utensil and slide it down into sides of each jar a couple times to remove trapped air bubbles. If necessary, add or remove syrup, to ensure a 1/2 inch headspace.

Wipe the rims of each jar with a wet cloth (or paper towel) to make sure there is no syrup of food residue on jar rim. This is done to ensure a good seal. Place a hot flat lid on top, then screw on the screwband (jar ring) to fingertip tightness.  Carefully place the jars in a upright position on the rack in the water in canner. Jars should be completely covered with water (by at least an inch over top of jars). Put lid on canner. 

Bring the water in canner to a boil. AFTER water reaches a gentle boil, process pint jars for 20 minutes. Process quart jars for 25 minutes. Once processing time is done, turn off heat. Remove canner lid. Wait 5 minutes, then carefully (with canning tongs) remove hot jars to a dish towel. TIP: Do not place boiling hot jars directly on kitchen counter, as temperature variations could cause jars to crack.

You will hear the jars make a "pinging" sound as they seal. Let jars cool completely (8-10 hrs.), then check to ensure they have properly sealed. To check, press lightly in the center of each lid. There should be NO resistance. Wipe the outside of jars, label, and store in pantry. Remove screw bands from jars before storing in pantry. Do not stack jars on top of each other (this can cause lid to unseal). If any jars did not seal properly, refrigerate pears, and eat within a few days. Canned pears will last a year or longer in the pantry, if properly sealed.