Gluten free., Certified Gluten-Free. Est. 1897., A lil' sweet, a lil' heat., Enjoyed everywhere., This is the culmination of 120 years worth of fine mustard-making tradition. Inside is over a century of experience, the finest ingredients, generations of expertise and, of course, really really good mustard. This is bold at its best. koopsmustard.com. Made in Wisconsin., Product of USA.