Why does white vinegar taste better when at restaurants? Just got back from dinner, where I had some decent fish and chips with white vinegar, and a thought came to me: At restaurants, I've found the white vinegar there helps to accentuate the flavour of the dish, mainly French fries. But when trying to do the same thing at home, the taste is more like I had just thrown on water as opposed to vinegar.

Barring that I'm imagining things (and it's entirely possible), I wonder if anyone else can shed some light on this at all?
According to a quick search on Google, there are two other types of vinegar served in fish and chips shops along with malt vinegar. 

The first (and my best guess) is onion vinegar -- which is white vinegar that has been used to pickle onions. This is clear, but at minimum contains onions and salt, and perhaps sugar and other pickling spices. (I should note that the recipe I linked to uses malt vinegar to pickle the onions, but you could certainly achieve the same result with white vinegar.)

The second vinegar is actually called non brewed condiment, and isn't actually vinegar. It's ascetic acid, water, and a bit of caramel coloring. The coloring would make it brown, but it wouldn't have the malt flavor.