Room temperature or refrigerated? Growing up, we never put our ketchup in the refrigerator. I don't think anybody I knew did. Restaurants left room temperature ketchup on the tables. With normal usage ketchup will be used up before it goes bad. Then I found out that some people actually keep their ketchup in the refrigerator. Why? I hate the taste of a hot french fry dipped into cold ketchup. Fish right out of the fryer? Same thing. Same with mustard. I store mustard in the pantry at room temp.