Mysterious calories in vinegar?
Monday, August 31, 2009 15:23Q. I'm creating a recipe and I noticed that 1 cup of cider vinegar is listed as 50 calories, with 0 fat, 0 protein, and 2g carbs. My understanding is that carbohydrates are approximately 4 calories/gram, so how can this be?
A. That didn't look right to me either so I contacted the Nutrient Data Laboratory of the USDA for an explanation. It turns out that vinegar is a bit of a special situation.
There are a few compounds in foods, such as alcohol and organic acids, which contribute calories but can't be considered carbohydrate, fat, or protein. Vinegar contains one of these "none of the above" nutrients, an organic acid called acetic acid, which contributes about 3.5 calories per gram.
A cup of cider vinegar contains about 12 grams of acetic acid. So the calorie total includes about 8 calories from the carbohydrates plus another 42 calories from the acetic acid.
Mystery solved! Thanks to Robin Thomas, MS, RD, of the Nutrient Data Lab for clarifying the issue!