网页Kof-K, a Teaneck, New Jersey –based Kosher certification agency, [1] is one of the "Big Five." [2] As of 2010, more than one third of all food sold in the United States has kosher supervision, [3] 80% of it from one of the "Big Five." [2][4] Kof-K symbol for Kosher. (placed on certified products)