Core and chop the pears (peeling is optional). Put them into a large pot and add the ginger and water. Bring the mixture to a low simmer over medium-high heat, then cover the pot and reduce the heat to low. Let the pears cook for about 30 minutes, stirring occasionally, until they are soft.

Use an immersion blender, regular blender, or food processor to puree the pear mixture until smooth. You may have to work in batches if you do not use an immersion blender.

Return the pear puree to the saucepan if you used a regular blender or food processor, and stir in the maple syrup, spices, and lemon juice.

Bring the mixture back to a boil over medium heat, stirring often. Reduce heat to low, and cook until the mixture thickens, about 30-60 more minutes.

Meanwhile, prepare your boiling water canner for a water bath method. Put the canning rack at the bottom of a large pot and heat the jars in simmering water until it's time to use them. Wash the lids in warm soapy water and set aside until ready for use.

Spoon the hot pear butter into the prepared jars, leaving ¼ inch of headspace. Use a wooden chopstick or bamboo skewer to dislodge any trapped air bubbles.

Wipe the jar rims, then center a lid on each jar and apply the band, adjusting to fingertip tight. Place the jars into the boiling water canner.

Process in a boiling water bath for 15 minutes. Turn off the heat, remove the pot lid, and let the jars sit inside for 5 minutes.

Use a jar lifter to remove the hot jars and let them cool for 12 to 24 hours. Check to make sure the lids are all sealed, they should not flex when the center is pressed.