My test was always to gum the food myself and see how soft it was. I'd stick a chunk of apple, pear, or whatever in my mouth and use my tongue to smush it against the roof of my mouth. Sounds weird, I know, but that's what babies do with their tongues and gums when they "chew." If I could mush it up without much effort, then the food was soft enough. If not, I'd cook it a bit.