Louisa Shafia's Watermelon, Mint, and Cider Vinegar Tonic

Every week -- often with your help -- Food52's Senior Editor Kristen Miglore is unearthing recipes that are nothing short of genius.

Today: The most refreshing drink for your sunny picnics and barbecues doesn't have alcohol or sugar -- just vinegar, of course.

"You have to get the crispy pig face and the drinking vinegar." This could be a cruel sorority hazing rite, but it's just the start of a nice dinner out in 2013.

Like compost cookies or Cronuts, drinking vinegars are one of those sweeping trends that seems to be fueled by how unpleasant they sound (their other name, shrubs, isn't much more inviting). 

But even if drinking vinegar sounds like a dare -- and maybe that's why you ordered it -- it's anything but. It's sweet and sour and icy-cold. It vibrates and clangs with fruit and vinegar, and soothes with sweetness and mint. It is the most refreshing drink you will have this summer.

And it's not even new, really.

It's age-old in lots of places -- a means of preserving fruit in pickled, drinkable form as much as a way to cool off. In Iran, sekanjabin is the sweet, vinegary base to a cooling tonic, as well as a dip for cold romaine lettuce leaves -- drink and salad dressing in one.

In The New Persian Kitchen, Louisa Shafia takes the traditional drink -- which is often made with white vinegar and sugar -- and puts her trademark modern, ingredient-focused stamp on it.

More: Try Louisa's Vinegar Carrots with Toasted Sesame Seeds.

Here's how to make it like Shafia does: Make a hot honey syrup (that's honey, water, and a little salt), then pour it over chopped watermelon and a packed cup of mint leaves.

Let that cool off, stir in some cider vinegar, then let it all hang out for a few hours or more.

When you're ready, strain to get your concentrate, dilute with water to taste (sparkling or still), gulp. A bonus: you get to eat the pickled watermelon (if desired).

And this is just the beginning. "Try adding a few slices of ginger, fresh rose petals, or a stalk of crushed lemongrass." Shafia wrote to me. "Instead of watermelon, try cherries (including sour!), or sliced apricots, peaches, plums, or grapes."

While there's only so much lemonade you can drink in the hot sun before the sugar starts to go to your head -- and boozy drinks pose a similar, sloppier problem -- this is an elixir you could drink all day.

And because it's a grown-up drink without alcohol, you can take it on a picnic, at any park, without having to look side-eyed at cops that might pass by. You can stare them straight in the face and tell them what you're drinking: vinegar.

Louisa Shafia's Watermelon, Mint, and Cider Vinegar Tonic

From The New Persian Kitchen (Ten Speed Press, 2013)

Makes 5 cups concentrate 

3 cups water, plus more to serve
1/4 teaspoon sea salt 
1 cup good-quality honey
6 cups coarsely chopped watermelon 
1 cup tightly packed fresh spearmint 
1 cup cider vinegar
Ice cubes

See the full recipe (and save and print it) here.

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Photos by James Ransom