Tomato Meets Blender: Like Magic, It's Mousse

By Andreas Viestad
Special to The Washington Post
Wednesday, August 13, 2008

I have a thing for tomatoes, which at their best encapsulate the finest elements of summer. They are berries, fruits and vegetables all in one. Bite into a perfectly ripe tomato, and it is like savoring a glass of good wine. First come sweetness and tartness in multiple layers, playing with your taste buds, and then a lingering finish.

In my passion, I chase perfection. I have traveled to Sicily to taste small, wrinkly ones born out of the sun-scorched earth; I have pinched them wherever I have seen them grow ("It's just research, Ma'am"); and I have visited incredibly boring tomato festivals just to see if they might lead me to a better tomato.

I have even ventured into tomato farming; last year I grew more than 100 types on a farm I lease just outside Cape Town, South Africa, where I spend most of my winters. I grow them in all colors and shapes: yellow, brownish, zebra-striped, black, crimson and pink; small as berries and big as grapefruit. Some are sweet, others slightly sour; they can be intensely flavored or watery with ephemeral aromas that are just barely there, like a breeze, and then gone. None is perfect, and each is a little different; together they constitute an ever-changing world of flavors that is better than any singular brilliance.

Living with, and to some extent for, tomatoes, I have made a rule: The better the tomato, the less it should be subjected to cooking. Usually I just make a tomato salad, doing the same thing nearly every day, but because the tomatoes are always different, it never tastes the same. When I make a pasta dish, I tend to use chopped raw tomatoes rather than a cooked and flavored tomato sauce.

To that rule I have one exception: a treatment of the tomato that is drastic and gentle at the same time, keeping the integrity of the fruit while allowing an unlimited degree of manipulation. I make a delicate take on tomato mousse, or rather a series of mousses, according to my whim and what I think will suit a particular tomato or mix of tomatoes. The technique can even be used on tomatoes that are not grown on my own farm, from the labor of my hands. It gives normal supermarket tomatoes a chance to shine.

Tomato mousse is usually the kind of dish you get at the derriere-garde of high-end restaurants, a flashback to the ignoble culinary atrocities of the 1970s and '80s, a wobbly, adulterated, gelatinous affair with little to recommend it save perhaps a half-decent Thousand Island dressing. What is little known, however, is that the tomato has the capacity to turn into a thin mousse with no added ingredients and only a little assistance from you.

The method is as follows: You puree tomatoes in a blender for several minutes. Then you pour the frothy puree into a container and refrigerate it. When you take it out after a couple of hours, it has slightly gelled. It is not very stable: It does not travel well and does not keep for more than a day or two before it starts to sweat a little. But because there are no additives (no gelatin, eggs, cream or agar) to assist in the jellification, there is also nothing masking the flavor of the tomato. A Black Krim tomato will still taste like a Black Krim tomato, a Buckeye like a Buckeye, and a pale supermarket tomato like it is in need of a pinch of salt and sugar and perhaps a little basil in order to be any good. And because the tomato is no longer within the confines of its skin, you can give it just what it needs.

It is really quite ingenious. It is also somewhat of a mystery. I consulted more than a half-dozen scientists on three continents, and it is evident that no one knows exactly what makes the tomato gel so nicely, with so little effort. I originally got the idea from the French food scientist Hervé This, who merrily told me that he knew it worked but had no clear idea why. His best qualified guess, echoed by most of the other scientists I spoke to, was that it probably had to do with "pectins, and enzymes that play with pectins and modify them."

"Pectin molecules are like Christmas trees or balls of yarn," Einar Risvik, the research director at the Norwegian food research institute Nofima, explained to me. "When you puree a fruit or vegetable containing pectins in a blender for a long time, you cut them into smaller pieces, allowing water to be trapped between these pieces." Fibers in the tomato probably help stabilize the gel.

Regardless of the science, once you have mastered the fine art of placing tomatoes in your blender and waiting much longer than you would think necessary (minutes, not seconds), you can continue in as many directions as you want. I use the technique to create various flavor experiences, such as the classic combination of tomatoes and basil in the recipe for Tomato Mousse With Basil Oil on this page. It can be served by itself or with prosciutto or mozzarella, or allowed to enter a more decadent world in the company of oysters or clams.

Using different-looking tomato varieties in multiple-layered, multiple-colored mousses is a visually startling way to play with your food and probably one of the most beautiful (and time-consuming) ways to serve a bloody mary.

Even more fun can be had if you add sugar to a mousse made with very sweet tomatoes. It is a rebellious act, undermining Nix v. Hedden, the U.S. Supreme Court's 1893 ruling that the tomato is a vegetable even though it is botanically a fruit. This approach takes a tomato back to its origins, and it is beyond the reach of any jurisdiction but your own preferences. I make a combination of tomatoes and orange marmalade or raspberries that sounds like a strange experiment but in fact tastes like the most natural thing in the world.

Andreas Viestad, author of "Where Flavor Was Born" and co-host of the upcoming public television series "Perfect Day," can be reached through his Web site at http://www.andreasviestad.comor at His Gastronomer column appears monthly.

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