Why do certain vegetables shrink so much when cooked


I am (at least I would like to think) a better than average home cook but I still can’t wrap my head around why vegetables shrink when they are cooked. I know some like kale let out water but what about ones like onions and mushrooms that seemingly don’t let out water?

In: 5

Seemingly don’t let out water? Onions are like 90% water. There’s a cooking technique that’s literally called sweating onions.

The water content, it’s the same reason dried fruit shrinks, it gets rid of all the water contents and you’re left with just the vegetable/fruit

That’s a tricky one. Of course it is because of water loss, but we should discuss that if it loses a lot of volume, it might be cooked too long. I struggle to get the veggies browned without over cooking them. It requires higher heat and careful timing. Sometimes I get it right on and sometimes I get microscopic pieces. Always tastes good though.

When you cook them the plant cells burst and lose water and collapse. Imagine a bunch of water balloons glued together, and you pop half of them. The overall shape will shrink down a lot.

If you’re cooking vegetables to the point where you’re notice a lot of volume loss, you’re also losing a lot of nutrients because they’re water soluble and they’re coming out with the water, assuming you’re not roasting them in which case it’s just water escaping as steam (not saying you shouldn’t ever cook them a lot because, you know, caramelized onions!)