Combine apples and water in a large pot. Bring to a boil, then reduce to a bare simmer. Cook, uncovered, until apples break down easily when squeezed with tongs, about 15 minutes.

Using an immersion blender, purée apples until desired texture is achieved. If sauce is too watery, simmer over low heat for 5 more minutes to tighten. Add salt to taste. Serve warm, or chill in the refrigerator for several hours to serve cold.