Quinoa seeds are naturally coated with saponin, which one grainy has said tastes like dandelion milk (ew). There are machines out there to get the coating off, but here in Canada quinoa growers usually use the washing machine method:
- run your washing machine through a cycle with vinegar instead of laundry detergent, to clean out any soap residue.
- place the quinoa seed in a pillow case and tie it shut.
- using just the water, run your washing machine through 2-3 cycles with the pillowcase of quinoa inside.
- taste the quinoa seed to check that it's saponin-free.
- when the saponin's been washed off, empty the seed onto trays and dry before storing.