u003cbr/u003eIt is covered in a bitter substance called saponin. In nature, saponin protects the seeds from pests and birds. u003cbr/u003eu003cbr/u003eu003cbr/u003eBecause saponin is bitter tasting and can lead to gastrointestinal distress, quinoa must be well-rinsed before serving. Alternatively, you may by pre-rinsed seeds.