T. Susan Chang is a New England-based freelance writer and a former Kellogg Food and Society Policy Fellow. She also is the Boston Globe's regular cookbook reviewer, and her articles on cooking, gardening and nutrition appear in a variety of national and regional publications. You can find more information at her Web site, tsusanchang.com.
Of course you already know how to use a blender. But the following precautions will help keep your soup-a-rama from turning into a wet, frustrating fiasco. Every one of them could be subtitled "Ask Me How I Know."
• Don't use a food processor. The bowl is too wide and shallow, and the blade will never puree the soup as smoothly as the howling vortex of a high-speed blender.
• Never fill the blender more than half full, or it will certainly erupt while you're peering into the top, forcing you to clean your glasses repeatedly.
• Instead of using the blender lid, cover the open blender with the bottom of a lightweight metal mixing bowl. When you're blending several batches, it's a lot faster than the lid. You can catch drips with it when you're ladling the soup in, and scrape off the drips with that rubber spatula you should always have at hand when you're using a blender.
I had never given much thought to cold soups before that steaming summer afternoon, as we sweated on the sun-baked pavement, our palms moist and our lips dry. With the idleness known only to childless couples on vacation, we'd squandered humid hours trying out vintage saxophones in the unventilated antique stores of a Hudson River town.
Our refuge, though, was in sight: a cool, dim eatery, crisp with white linen and nearly empty. As we took our seats, shedding the heat in palpable waves, the waiter brought forth a plate of chilled zucchini-mint soup. It was a pale, sweet platter of liquid refreshment. And unlike pretty much any other zucchini dish I can think of, it was gone in under a minute.
You'd think that cool soups, pastel-pale or jewel-bright, would be everybody's fallback food for summer. Could there be a better solution for dinner on a hot day? You wander in at sunset after a hard day's lounging in the sun and pull a chilled tureen out of the fridge. You blithely sweep off the cover and set to it with a silver spoon. Everybody's happy.
In practice, however, people just don't go for it, because the casual elegance of a cold soup doesn't come for free. With a few exceptions, those alluring cool soups still have to be cooked over a hot stove by somebody, somewhere, sometime, somehow. That glistening vichyssoise you love at 7 p.m. was a sweltering, churning mass of potato chowder you wanted nothing to do with 12 hours earlier.
Three of the four soups I'm sharing start life on the stove (one doesn't — that's a freebie). But I've made an effort to streamline them down to their essences. None calls for more than six ingredients, if you don't count salt and pepper. None takes longer than an hour to prepare. And I promise you, they're worth it.
Those hot, lazy summer days we once enjoyed? They're now a decade in the past and fast acquiring a sepia hue. We're toiling in the fields of parenthood, shoulder to shoulder with countless other couples. Yet the relief we feel when evening falls is greater than ever.
Like the sound of ice clattering in the cocktail shaker, or the first whiff of charcoal smoke from the grill, that first sip of cool soup is a one-way ticket away from the labors of the day. Gone are the hot hours gardening. The sweaty chores, the stifling commute, the shuttling from camp to soccer to music lessons — all consigned to the dustbin.
With any luck, even the hour you spent making soup earlier this morning will seem like a distant memory. It may even be a happy one.
Cold Soup 101
A really good cold soup depends on four elements. If any of them is missing, the soup is liable to fall flat. I made up these principles, though I'm sure you can find a whole philosophy of cold soups somewhere, probably in a French cookbook.
Color. As far as I'm concerned, any color will do as long as it's not brown, or even faintly reminiscent of brown. Brown is for warm, cozy November lentil soups. Brown summer soup just makes me sad. If you, like me, enjoy a colorful soup, be careful with your vegetables. You can stifle and sweat them in a closed pot within an inch of their lives, but keep an eye on them and don't let them brown. In red, fruity soups, acid is your friend, brightening and preserving the color. In soups made from green vegetables, it is your sworn foe. It will turn your greens to a horrid, defeated olive. So go easy on the lemon.
Texture. Unless you're deliberately making a chunky cold soup like gazpacho, the texture of a cold soup should be like silk. Nothing in it should remind you of the hard work of chewing. That means using a blender, followed by a fine strainer. Don't try to use a food processor. You need the churning, foaming vortex of a blender on its highest speed to do the trick. Don't try to substitute a colander or even a food mill for the strainer (unless you have a mill with a superfine disk).They'll just leave you chewing little mealy bits. Blending in cream, yogurt, buttermilk or half-and-half at the end also helps smooth things out.
Flavor. Summer soups demand a little tartness to liven up their deep and mellow flavors, which tend to fade while the soup is cooling. For a little smooth tartness, you can use buttermilk or yogurt. For a lot, there are lemon, lime and other citrus juices. Naturally acidic soups like roasted tomato, however, do just fine on their own.
Time. Soup needs at least four hours to get cold — period. (You can shave off a few minutes by cooling it over ice before chilling it, though it's hardly worth the trouble.) If you don't have hours of chill time, just wait and serve it tomorrow. Lukewarm soup is OK, but it just doesn't compare to the slow, deep effect of stone-cold soup. The best strategy for summer soups is to make them in the morning when you still have the cheerful disposition required to blend and sieve the soup. Also, you're not warming up the kitchen in the unbearable afternoon heat, and the soup's chilled and ready well before dinnertime.
This soup is so luxuriously satiny, you don't need any additional cream, half-and-half, buttermilk or anything else to smooth it out. The corn blends with the stock and gives it an astonishing sweetness, without added sugar.
Makes 4 to 6 servings
6 ears of fresh corn, husked (don't snap off the stalk — you'll need it as a handle)
2 leeks, white parts only
4 cups vegetable or light chicken stock
1 clove garlic
1 bay leaf
Salt and pepper to taste
Chopped scallions or chives for garnish (optional)
Rub the husked ears of corn with a towel to remove the last silk threads. Grasping the stalk end, hold the cob pointing straight down in a large mixing bowl and cut off the kernels with a sharp knife. Set the kernels aside. Break the cobs in half and place them in a stockpot.
Halve the white part of the leeks lengthwise. Rinse them, peeling back the layers to get at any sand trapped between them. Chop them coarsely and add them to the stockpot with all of the remaining ingredients except the corn kernels. Add a little salt to taste. Bring it to a boil and simmer for 25 minutes.
Remove cobs and bay leaf and discard. Taste the stock for seasoning. Then add corn kernels and simmer an additional 5 minutes. Using a blender set on high, puree the soup in batches and strain it through a fine strainer or sieve, discarding any fibrous solids. Chill at least 4 hours.
This is what my 2-year-old daughter calls "pink soup." Cold berry soups are often made with orange juice, but I prefer cranberry for color and tartness. Naturally sweetened cranberry juice tends to be less toothache-sweet than the high-fructose corn syrup variety. Choose red fruit for a brilliant rosy color, or add blueberries if you like it more purply. This is the soup version of a smoothie, so it's not terribly filling. But it really hits the spot when it's beastly hot outside. Plus, you don't have to turn on the stove even once.
Makes 4 servings
3 cups mixed fresh or frozen berries (raspberries, strawberries and/or blueberries work well)
1 cup cranberry juice (naturally sweetened if possible)
1 cup whole or low-fat yogurt
Juice of 1/2 lemon
1 to 2 tablespoons honey, to taste
A dollop or two of sour cream or creme fraiche for garnish (optional)
In a blender set at high speed, whiz the berries and juice together until you achieve a smooth puree. If you're using frozen berries the puree will be rather slushy. You'll need to stop and scrape down the sides of the blender periodically with a rubber spatula.
Strain the puree to remove any berry seeds or fibers. Place the puree back in the blender and add the yogurt, lemon and honey to taste. Serve with a dollop of sour cream or creme fraiche (or if you really feel like living large, put some sour cream, yogurt or creme fraiche in a squeeze bottle and do what those prep cooks in fancy restaurants do: Make some spirals or dots of cream and then drag a toothpick through them for spectacular effects).
This is a great solution for the too-many-tomatoes problem some of us have in mid-August. If you don't feel like firing up the grill just to make a soup, then grill the vegetables when you're grilling something else. You can hold them, peeled and covered, for a day or two in the fridge. The rest of the soup is easy.
Makes 4 servings
2 pounds ripe tomatoes
1 red bell pepper
1/4 cup olive oil
1 onion, chopped medium
3 garlic cloves, coarsely chopped
1 cup chicken or vegetable stock
Salt and pepper
Preheat a gas grill, or start some coals for a charcoal grill. While the grill is heating, cut a slice off the top and the bottom of the red pepper and reserve. Cut the pepper open; remove the membrane and seeds. Flatten the pepper into one wide strip as best you can.
Remove any tomato stems.
When the grill is hot, place the whole tomatoes and the pepper pieces, including the top and bottom, over the hottest part of the grate. Grill, turning frequently, until they're blackened and blistering on all sides. As they finish, transfer them carefully to a medium-size mixing bowl. Let them rest, covering the bowl with a lid or plate, for 15 minutes or until they're cool enough to handle.
While the tomato and pepper are cooling, place the oil, onion, garlic and a little salt to taste in a heavy pot. Turn the heat to low, cover and sweat for about 25 minutes. Stir a few times to keep them from browning. When they're done, the onions will be translucent and will have given off quite a bit of liquid.
While the onions are sweating, peel the tomato and pepper (discarding any remaining stems) and coarsely chop them. After the onions are done sweating, raise the heat, add the red vegetables and saute over high heat for 5 minutes. Add the stock and simmer an additional 5 minutes.
Using a blender set on high, puree the soup in batches and strain through a fine strainer or sieve, discarding any fibrous solids.
This is a very satisfying version of the zucchini-mint soup I so enjoyed. I've never quite figured out how to add the flavor of the mint while still preserving the smooth texture. I'm still working on it. But using mint as a fine herbal garnish works well, as does using basil.
Makes 4 servings
1/4 cup olive oil
2 small to medium zucchini, coarsely chopped
1 onion, coarsely chopped
Zest of 1 lemon
1 cup chicken or vegetable stock
1/4 to 1/2 cup buttermilk, to taste
Salt and pepper
Basil or mint sprigs, finely chopped or julienned, for garnish (optional)
Place the oil in a heavy pot. Add zucchini, onion, lemon zest and a little salt to help draw out the juices. Sweat them, covered, for 25 minutes. Check and stir frequently. Don't let the zucchini brown. Don't overcook it, either, or it will take on an unappetizing olive hue.
When the vegetables are quite tender but not mushy, add the stock. Simmer everything together for 5 minutes.
Using a blender set on high, puree the soup in batches and strain it through a fine strainer or sieve, discarding any fibrous solids. Whisk in buttermilk to taste and chill at least 4 hours.