Using vinegar on french fries is somewhat of a less common tradition nowadays. The closest my generation might come to this is salt and vinegar potatoes chips. I had never heard of table vinegar packets or seen them before.
So I did some research to see if this was more common. Here is what I found.
Vinegar on fries is done traditionally in the U.K. (fish & chips). But is less common in the United States. Malt vinegar is a specific condiment used for fries. White vinegar can be used as a substitute and also for making homemade salt and vinegar chips.
That is not to say you won’t ever find fries with vinegar used in the United States. There is also some good ways to use vinegar for making fries.
French Fries and Vinegar
In the United States ketchup and salt are the most common condiments for fries. The English and tend to used malted vinegar and or mayonnaise. Malted vinegar is popular in the United Kingdom, Ireland, Canada and Australia.
By the way ketchup typically contains vinegar, it is sometimes listed as the second ingredient in popular ketchup brands.
Boardwalk fries originating from the boardwalks of Maryland and New Jersey are seasoned with malted vinegar. The Original Thrashers French Fries in Ocean City MD, opened in 1929 and serves fries seasoned with salt and vinegar.
Five guys restaurant chain in the United States has malt vinegar next to the ketchup. This is for using on the fries as a dipping sauce.
The most common and popular form is salt and vinegar potato chips. This is usually the only time the two come together in the United States.
Malted Vinegar: What is it?
Malted vinegar starts out by malting barley grains and brewing them into beer.
Similar to how wine vinegar is made directly from actual wine, malted vinegar is made from beer. The alcohol turns into vinegar after another fermentation process.
The color is usually brown and the taste is more mild and sweeter than purified vinegar.