The following is an excerpt from Saving the Seasons: How to Can, Freeze, or Dry Almost Anything by Mary Clemens Meyer and Susanna Meyer (Herald Press, 2010). The excerpt is part of a chapter titled "Canning."
Appe Pie Filling
Makes 7 quarts
About 35 medium apples
9 1/2 cups water
4 1/2 cups sugar
1 cup Clear Jel* or cornstarch
1 teaspoon salt
1 tablespoon ground cinnamon
1/4 teaspoon ground nutmeg
3 tablespoons lemon juice (optional)
*Clear Jel is a modified food starch that is more stable when use in canning. Regular cornstarch can separate or become watery.
1. Mix spices, Clear Jel, and sugar in large saucepan and add water. Cook until thickened, stirring constantly. Add lemon juice, if desired.
2. Slice apples directly into jars, adding layers of syrup as you fill each jar. This helps eliminate air pockets. Leave at least 1 inch headspace.
3. Tighten lids and process 25 minutes in boiling water.
To make pie with canned pie filling: Fill unbaked crust with filling. Put dabs of butter on top and add a top crust. Bake pie just until crust is lightly browned and filling is bubbly.
You can also freeze pie filling. Fill freezer containers (or an unbaked pie crust), exclude air, and seal.
What are good pie apples?
People have different opinions, but in general you should choose tart, firm, juicy apples. For canned pie filling, you also want apples that will hold their shape when cooked. Examples: Cortland, Jonathan, Rome, Winesap, Stayman, Golden Delicious, and Grimes Golden.
Read the original article, "Home Canning 101: How to Can at Home."