This recipe is relatively easy and worth the trouble. I like preserving my harvest in a variety of ways, especially when I have a huge crop!
This recipe is very similar to a recipe from growforagecookferment.
Put your chopped pears in a big pot with the ginger and water. Heat on medium low heat, and check as it heats. You may need to stir often at the beginning, to prevent burning, especially if you're using less water. Cover the pot and cook about 30 minutes, until the pears are soft.
Turn off the heat and use an immersion blender to puree the cooked pears. You can use a regular blender, but you'll have to blend one batch at a time, using a bowl to hold the unblended part as you go. Puree them finely.
Put the pureed pears into the pot, along with all the other ingredients. I like to use a very wide pot that isn't too tall. This speeds up the process of evaporation.
Cook this mixture 30-60 minutes on low heat. You want the puree to get quite thick, and as it thickens, you'll need to stir it more and more. I usually have to cook it closer to 60 minutes, but that will depend on the water content of your pears. While the pear butter/puree is cooking down, prepare your jars and heat the canner water.
I like to use 1-cup jars for jams and fruit butters. 1 cup is a nice size for a gift.
Sterilize your jars by filling them completely with boiling water, pouring boiling water over the rims and sides too. Empty out the water and put the jars upside down on a clean cloth on your counter. Put the lids and rings in a saucepan full of water and heat it over the stove. Fill your canner halfway with water and bring to a boil.