Why you should never cook potatoes in water

What disappears into the cooking water

The main issue with boiling potatoes is simple: water-soluble nutrients can move from the potato into the cooking water. Potatoes naturally contain potassium, vitamin C and several other vitamins and minerals. Research has found that boiling can reduce some of these nutrients, particularly when potatoes are peeled, cut into small pieces and cooked in plenty of water. The more surface area exposed, the easier it is for nutrients to escape.

Potassium is a good example. One study found that boiling potato cubes significantly reduced their potassium content, while shredded potatoes lost even more. Vitamin C is also vulnerable because it is water-soluble and sensitive to heat. Boiled potatoes aren't exactly unhealthy, but if you drain the pan and pour the water away, they lose some of their nutritional value.

There is another reason you may notice a difference: flavor. Potatoes cooked in lots of water can taste softer and more diluted, especially if they are overcooked. If you still prefer boiling, leave the skin on when possible, keep pieces larger, and avoid cooking them longer than necessary. Those few small changes help the potato keep more of what makes it worth eating.