Yes, you need to soak ALL non-sprouted grains (as well as legumes) before consumption overnight in warm water and an acidic medium like:
dairy: buttermilk, yogurt, milk kefir or whey
non-dairy: lemon juice, raw apple cider vinegar or coconut or water kefir
You can find more information about this on the Weston A Price foundation website. And here's a link to a chart that talks about each grain specifically...It does have a copyright printed over it, but you can stil see the information
I'm not sure about sprouted quinoa, but I know that regular quinoa has a natural coating called saponin that gives it a bitter taste if it is not rinsed off before hand.