Wow, this is a lot of work for very little yield but I must admit that it was worth it. I must say that I even liked the finished product. I'm not a fan of pears or apples cooked (I don't like pears raw, but I do like apples) and when my butter was going through the cooking process it was at a stage of being sauce at one time and I thought...GAG! After 3-4 hours late it was looking and smelling pretty good to me and I tried some and I liked it! It was nice and sweet and slightly tangy. The flavors were very simple and intense and I could taste the blend of pear and apple. Now I just have to make more since I only ended up with 4 half pints.
Yields 4 Cups (I recommend that you double this just to make the time worth while...it takes a long time but so worth it)
2 1/2 pounds Gala apples
2 1/2 pounds Anjou pears
1 cup packed dark-brown sugar
1/2 teaspoon Kosher salt
1 cinnamon stick
Peel, quarter, and core all of the apples and the pears. This takes some time, but if you're good with a paring knife this shouldn't be too painful. Take the fruit and chop it up (in batches if you need to) in a food processor. Don't worry if the puree starts to turn brown because you'll be cooking the bejeezus out of it. Put the puree into a large slow cooker and cook covered on high for four hours. Carefully puree until smooth (in batches if you need to) in the food processor and put back into the slow cooker uncovered for four more hours. It will not burn but turn dark and thick.
I made the mistake of putting the fruit into my larger slow cooker for one batch. So I transferred it to my smaller one, but by then it had taken forever to reduce down. If you double the batch the larger cooker will be fine. I finished the butter in a non-stick pan over medium heat, stirring constantly until the fruit was very, very thick and there wasn't much moisture. It should be able to hold it's shape if you stir it up with a rubber spatula and look a bit like canned pumpkin.
While the mixture is still hot fill your hot jars for canning. Process half pints according to the directions. I did mine for 12 minutes because of the high altitude.
I can't wait to give this as gifts! I'm planning on making a double batch again very soon!