Makes 11 cups 13 cups apples (3 ½ pounds), cored, 1-inch dice
12 ounces frozen apple juice concentrate
1½ cups water
17 ½ cups rhubarb (5 pounds), 1-inch pieces
1 tablespoon cinnamon
½ teaspoon nutmeg
1/3 cup honey, or more to taste

• Combine the diced apples, apple concentrate and water in a large soup pot over medium heat. Cover the pot and cook about 45 minutes till the apples are very soft.

• Transfer them to a food processor and blend until the skin disintegrates. Combine the pureed apples with the rhubarb and the spices in the same large soup pot. Cover the pot and cook, stirring frequently, until the rhubarb breaks down and gets juicy.

• Transfer the mixture to a slow cooker set on high. Place a couple of chopsticks or knives across the top of the crock and place the lid on top of them. This will allow the fruit butter to reduce without splattering all over your kitchen counter. Stir about once an hour.

• After 3 hours, stir in the honey.

• As rhubarb is rather stringy, we used an immersion blender to create a smooth and luxurious textured fruit butter. Or, you could blend your fruit butter a little at a time in a blender.

• Begin testing the butter for doneness after it has cooked for 3 ½ hours. Place a small plate in the freezer. Once the plate is cold, remove it and place a spoonful of your fruit butter on the plate. Look for: 1. Little or no clear liquid separating out from the fruit butter 2. A thick and spreadable jam-like consistency Next, taste the Rhubarb Apple Butter on the plate as it is much easier to taste its final flavor when it’s cold. If you prefer sweeter fruit butter, add additional honey to taste.

• If you choose to can your fruit butter, put it in a hot water bath for 13 minutes