I bet it is to kill some bacteria or something but is this really important? Is it an issue like once in a million times.
It would save allot of time to skip this step.
Please tell me why I can not.
I now open the floor for debate.
The casual cook (the majority of people) do not really know what a simmer is. By coming to a boil and falling back to a simmer, most people can cook this to a satisfactory result. If you really know how to cook, can hit and hold a real simmer, you may not need to follow those instructions so closely. On the other hand, hitting a boil, may help make the quinoa more permeable as well or denature the starch to fully hydrate that only hitting a simmer may not. I don't know those things to be factual, just theorizing possibilities. Wouldn't hurt to look up quinoa in something like Harold McGee's On Food and Cooking.
I've found a terrific way to cook quinoa that eliminates that soapy taste and results in firm, yet fluffy grains. Too often it's overcooked and mushy or too wet.
Rinse the quinoa in a fine sieve under luke warm water. Shake the sieve to get rid of as much water as possible.
Warm 1 tablespoon oil (I like olive oil) in a sauce pot over medium high heat. Add the quinoa and toast, stirring often to evaporate all the rinsing water. When the quinoa starts to sizzle and make crackling sounds, add water (1 cup quinoa to 1 1/4 cup water), bring to a boil, then cover, reduce heat and simmer 20 minutes.
Remove the pan from the heat, lift the lid and stretch a kitchen towel over the pot then replace the lid. Allow to stand for 10 minutes.
Voila! Fluffy, tasty toasty, quinoa!