So, why does quinoa double in size when cooked? It's because of the way the starches inside the quinoa grain absorb water. It's kind of like when you throw a sponge in the bathtub and it soaks up all the water - quinoa does the same thing, but instead of getting all pruney, it gets nice and fluffy!
Now, you might be wondering why this matters in the grand scheme of things. Well, portion control is a big deal, especially if you're trying to watch your figure or manage your diet. If you're using quinoa as a main ingredient, knowing that it's going to expand when cooked can help you plan your meals more effectively. And, let's be real, who doesn't love a good value meal?
For example, let's say you're making a big batch of quinoa salad for a picnic. If you use a cup of uncooked quinoa, you can expect it to yield about two cups of cooked quinoa - that's a lot of salad! By understanding how quinoa behaves when cooked, you can avoid ending up with a mountain of leftovers (although, let's be real, quinoa leftovers are never a bad thing)!
Cooked Quinoa Gi at Jenny Ingram blog