In summer, this girl’s fancy turns to (with apologies to Alfred Lord Tennyson) thoughts of local, fresh produce. On warm evenings at home, the pre-dinner baguette and cheese that so appealed—and surely packed on the pounds—in colder months give way to light appetizers like fresh summer rolls, tomato-mango-tomatillo-red onion salsa and chips, ripe melon with prosciutto, caprese salads, and chilled soups— all celebrating the dazzling bounty of a late summer harvest.
Over the next few weeks, I’ll be sharing a few of my favorite chilled soups—tracking that harvest from mid-summer zucchini to late-summer beets and tomatoes, tomatoes, tomatoes.
To start, here’s a chilled zucchini soup that’s creamy yet light; bright yet complex — thanks to buttermilk, yogurt, lime juice, and a secret ingredient that (if I never told you) you’d never guess was in there: sliced mushrooms.
Ingredients for the cold zucchini soup
With thousands of “cold zucchini soup with yogurt” recipes out there, where mine departs is in preparation. Instead of slicing the zucchini and attempting to sauté it, I feed big chunks into the tube of a food processor fitted with a medium grating disk. I swear, shredding the zucchini is quicker and less labor-intensive than slicing it.
Why do I do this? Well, zucchini is about 95% water – which brings me to the “attempting” part of sautéing it. You may have noticed when, despite best intentions and perfectly good-looking slices of zucchini, your goal of sauté turns to mush. Don’t blame yourself. Blame the extreme water content of this otherwise reasonable vegetable. And mitigate it by shredding and salting it, as I do.
Specifically, dump the shredded zucchini into a large colander that sits in a big mixing bowl. I mix in a few tablespoons of kosher salt with my fingers. And walk away to let the salt to its magic.
Shredded zucchini after salting
When I come back—after 15 minutes or three hours, all the same — that pile of zucchini is reduced to about half its original volume, the salt having leeched much of the water. The no-longer waterlogged zucchini is now sauté-able (which I’m sure is not a word) – shortening the cooking time and improving texture and flavor of the soup.
And what about that clear, pale green salty water that has accumulated at the bottom of the bowl? Liquid gold: don’t throw it out! Unlike the bitter water forced of eggplant by salting, this stuff is good. Consider it broth – and add it to the soup later on.
And know that within this recipe, no ingredients (beyond zucchini and alliums) or proportions or instructions are sacrosanct. Got yogurt or buttermilk but not both? Whatever. You’ll make it work. Got onions but not leek or vice versa? Fine. Forgot to pick up mushrooms? This soup is a keeper, so next time.
And heck, if you’re not in the mood to engage your food processer, just slice the zucchini and add them to the onions in the pot. You won’t hear that sizzle. And cooking will take a little longer. But chilled zucchini soup is pretty much impossible to get wrong.
Chilled Zucchini Soup with Buttermilk, Yogurt, and Lime
Ingredients
- 2 T olive oil
- 1 T butter
- 1 medium onion, coarsely chopped
- 1 leek sliced**— white and tender green parts only.
- 3 medium* zucchini, grated
- 2 T kosher salt
- Handful (7-10) button mushrooms, sliced
- 1 1/ 2 to 2 cups chicken or vegetable broth
- 1+ cup zucchini broth (from salting the zucchini)
- Coarse salt and freshly ground pepper, to taste
- 8 oz. buttermilk
- 8 oz. yogurt
- Juice of 2-3 limes
- cherry tomatoes, quartered, fresh basil, lime juice, for garnish
Directions
- Cut the zucchini into chunks and feed them into a food processor fitted with a medium grater. Pulse to shred.
- Dump the grated zucchini into a colander you’ve put inside a large mixing bowl. Add the salt, mix with your hands and leave for 15 minutes to three hours.
- In a large soup pot, heat the olive oil and melt the butter. Add the onions and leeks. Stir frequently so they sweat and soften, but don’t brown.
- Pick up grated zucchini, giving each handful a squeeze to release more water. Add to the pot with the onions and leeks and turn the heat up to medium. The zucchini will cook quickly. After a couple of minutes add the sliced mushroom and a few grindings of black pepper. Cook for another 5 minutes.
- Add chicken or vegetable broth and the zucchini water. Cook at a low simmer for 10 minutes. Turn off heat to let the soup cool.
- Once the soup has cooled, process it well, in batches, in the food processor—using the regular “S” blade. Put the mixture back into the colander fitted over the same bowl. Pressing a wooden spoon against the mesh, strain the soup into the bowl. Add buttermilk. Taste. Add lime juice. Taste and adjust for acidity (lime), salt and pepper, and the texture you prefer.
A few minutes before serving, quarter and salt a handful of cherry (not grape) tomatoes in a bowl with shredded basil and a few squeezes of fresh lime juice.
To serve: ladle soup into bowls. Add to each a dollop of yogurt, a tablespoon (or more) of the cherry tomato mixture, and a pretty sprig of basil – arranged any way you like.
* I consider a medium zucchini to be about 8″-10″ long
** If you don’t have leek, use more onion.
