Science agrees: There’s nothing better on a hot day. 

There’s a reason lemonade continues its reign as Ultimate Summertime Refreshment, and it has nothing to do with the irresistibly cute kids selling it down the block (though that helps). Scientifically speaking, what makes lemonade so satisfying on a sweltering day is its combo of cold (duh) and tart. Sour flavors stimulate salivation better than do other taste sensations, like sweet, bitter, salty, or umami, says Cordelia Running, an assistant professor of food science at Purdue University, in Lafayette, Indiana. At the first swig, the mouth turns on its sprinklers to wash away the citric acid and neutralize it, says Running.

Also, research shows that the cooling of the mouth by cold drinks satiates thirst and is perceived as refreshing. A similar response occurs with other acidic liquids, like grapefruit juice and, believe it or not, vinegar. In fact, since fresh lemons were scarce on the dusty Oregon Trail in the mid-1800s, pioneers downed a concoction of apple cider vinegar, water, and sugar. Moral of the story: If you’re lucky enough that life hands you lemons, make lemonade.

Discover fresh twists on the classic recipe here