[logfromblammo]

Mustard, mayonnaise, and chile-vinegar sauces like Tabasco or Frank's RedHot are the only sugar-free sauces I can think of at the moment.

Most everything else either has sugar or an artificial sweetener in it--or some back-door sugar, like raisin paste, or fruit juice concentrates.

It is likely because condiments came from preserved foods, and those generally require a high concentration of sugar or salt, or a low pH, in order to avoid spoilage. And some are concentrated from foods that are naturally sweet.

I think the sweetness was always valued in a sauce, and substituting the previous source of the sweetness with corn syrup or HFCS is a more recent trend, to cut costs. So it's the latter: popular sauces were adulterated with sugar.

[emmanuel_1234]

Heinz mayonnaise, at least where I live (outside of the US) contains an ungodly amount of sugar, it is the second ingredient, and makes it properly disgusting.