Is Quinoa chametz?
Quinos is certainly not chametz. It doesn’t need to be thrown out before Pesach, or to be sold.
Some authorities prohibit the consumption of consumption of quinoa on Pesach on account of the kitniyot custom, whereas other authorities are lenient on this matter. Those who refrain from cotton-seed oil and from kanola oil should certainly refrain from eating quinoa.
It is the common custom to consider a number of foods as not being included in the custom of kitniyos. Examples are potatoes, coffee, tea, garlic, nuts, radishes and olives (see Sha’arei Teshuvah 453:1; Chayei Adam 127:7).
Rav Moshe Feinstein (Iggros Moshe, Orach Chaim Vol. 3, no. 63) likewise writes that peanuts are not kitniyos, though those who have the custom, should refrain from eating peanuts on Pesach.
The Iggros Moshe explains that the custom to not eat kitniyos developed differently from other prohibitive customs, and he therefore rules that only foods that we know were specifically included in the custom are forbidden. A similar point is made by the Chok Yaakov (453:9).
It is based on this reasoning that Rav Moshe explains the accepted custom not to consider potatoes to be kitniyos, even though logically they should be (they are cooked in a similar manner, and they can be made into flour). The custom ofkitniyos dates to well before the time potatoes were introduced to Europe (in the 16th century), so that potatoes are a “new” vegetable that was not included in the custom.
Similar logic has been employed as a basis for permitting the consumption on Pesach of quinoa, which has only recently been introduced to the Northern Hemisphere from its native South America, and was never in the past considered to be kitniyos because it wasn’t part of the diet of those who refrain from eating kitniyos.
A difficulty with the approach of the Iggros Moshe is the fact that the common custom is to consider corn to be kitniyos, even though it, too, is a relatively new introduction to our diet (Mishnah Berurah 453:4). It is possible that because of the great similarity of corn to other kitniyos it is included in the custom in spite of its being relatively new, and the question of whether this logic can also be applied to quinoa remains open.
In practice, Rav Asher Weiss, Rav Dovid Feinstein, Rav Yisroel Belsky, and others, have prohibited. On the other hand, Rav Moshe Heinman, Rav Gedalya Schwarz, and others, have permitted. Note that quinoa is often packaged in plants that also package wheat and barley, and one must be careful to check the grains carefully to ensure that no chametz grains are present.