National Mustard Day is hosted by the National Mustard Museum in downtown Middleton and treats one of America’s most familiar condiments as a reason for an entire community celebration. The museum itself contains an enormous international mustard collection, giving the event a permanent home devoted entirely to the same theme.
Festival activities include free mustard tastings, games, live music, family entertainment and food such as brats and hot dogs. Sales and activity proceeds support the nonprofit museum. The next National Mustard Day is already scheduled for August 7, 2027, and Middleton tourism lists general admission as free, allowing visitors to attend without purchasing an event ticket.