Potatoes do shrink when cooked because they lose the water content. Uncooked potatoes are made of 21% of dry mass, (60-80% of potato mass is starch) and 79% of water. Depending on the cooking method, potatoes can lose anywhere from 2-40% of their weight.
Do potatoes get bigger when cooked?
In either case, the key is to make sure the whole potatoes or cubed potatoes are roughly the same size. This way, they will all cook at the same rate. If you're boiling whole potatoes, you might need to remove small potatoes from the water a little sooner and let larger potatoes cook a little longer.
What happens to potatoes when cooked?
When you bake a potato, the starch granules absorb the moisture within the potato. Within the confines of the potato skin, moisture soon turns to steam that expands with great force, separating the starch granules and making a fluffy baked potato.
Do you measure potatoes before or after cooking?
If you start with a raw potato weighing 200g, the actual potato will still contain the same amount of calories after baking, but will weigh less. So if using the raw figure in your diary you would enter 200g = 150kcals. But because baking has caused water loss, the weight of the potato is now only 110g.
