You don’t actually have to, as evidenced by the fact that every diner you’ve ever been to leaves its ketchup out on the table, but many folks opt for a better-safe-than-sorry approach nevertheless.

The FDA has officially declared that shelf-stable ketchup needn’t be refrigerated, but old habits die hard — as with soy sauce, leaving condiments out just feels wrong to some people. You’d be hard-pressed to find a difference in taste between refrigerated and unrefrigerated ketchup, suggesting that it really is either a simple force of habit or a safety concern. Just make sure you aren’t as lax about mayonnaise and salad dressing, which really do need to be refrigerated once you’ve opened them.