Toss apples with lemon juice in a large bowl and set aside.
Pour water into a Dutch oven over medium heat. Combine sugar, cornstarch, cinnamon, salt, and nutmeg in a bowl; add to water, stir well, and bring to a boil. Boil for 2 minutes, stirring constantly.
Add apples and return to a boil. Reduce heat, cover, and simmer until apples are tender, 6 to 8 minutes. Cool for 30 minutes.
Ladle into 5 freezer containers, leaving 1/2 inch of headspace. Cool at room temperature no longer than 1 1/2 hours.
Seal and freeze. Can be stored for up to 12 months.