I just bought a huge bag from Costco, Organic Earthly Choice, product of Bolivia. It does note that it is produced on equipment shared with peanut and tree nut products.
I also have a new unopened bag from Costco. It is Bob's Red Mill USDA organic whole grain quinoa, gluten free, country of origin is Bolivia. Per Bob's Red Mill web site it is grown in Peru, and manufactured in a facility that also uses soy, wheat, and milk. The package says soy & tree nuts.
The article that Tex mentions above indicates Ancient Harvest as an acceptable brand. Ancient Harvest is sold at Sprout's Farmers Market as well as other local stores.
I have a favorite Quinoa salad recipe. The last time I made it I found myself being more loose but thought it was the raw veggies in it. I have some plain Quinoa cooked up in the refrigerator. I will have to pay attention to whether or not I react to it.
