A warm condiment

Ketchup will keep longer refrigerated, but it can keep for a few weeks at room temperature as long as it's in a cool, dry place and out of direct sunlight.

Mustard doesn't have to be refrigerated for safety, but it does for quality.

Mustards keep their pungent flavor and their color longer if they're refrigerated.

While the acidity in mustard will slow down bacteria growth, it may not be enough to stop it completely.

So a squeeze bottle is less likely to be cross-contaminated than a jar in which you stick a spoon or knife.