The brand you buy matters more for quinoa than many other grains. Quinoa grows covered with a layer of bitter compounds called saponins. You want a brand that’s been well-washed so you can cook it straight out of the bag. Beware! Most brands say that they’re pre-washed. That doesn’t mean that their quinoa won’t require yet more washing before it’ll taste good. Bob’s Red Mill does a great job, with no bitter taste whatsoever, even when the quinoa is cooked like rice in a small amount of liquid.
Also, some brands do a really bad job separating the quinoa from the chaff. I’ve yet to find anything but quinoa grains in Bob’s packages.
This usually isn’t the cheapest brand of quinoa available. But, to me it’s worth spending a little more to have quinoa I can just measure and cook, without having to rinse it more or pick out bits of detritus.