Solid Sauces

All hail the New Gastronomy!

em>New York Times magazine: August 27, 2006

Poking around a bookshop in Paris last December, I came across a small handsome book. It was an unjacketed volume, bound in severe black cloth of the sort usually associated with spanking erotica. Picking it up, I found that it was actually more like a breviary, the title embossed in gold, the edges of the pages gilt, with a ribbon bookmark in ecclesiastical red; ''La Base'' is, in fact, a stylish little cookbook. The title means ''The Foundation,'' and the two-year-old self-published tome is a collection of core techniques and recipes by the Belgian author Filip Verheyden, each illustrated by a gastroporn-quality photograph by Tony Le Duc.

It's a seductive object, beautifully proportioned and designed, but also remarkably comprehensive. After covering basic kitchen skills, ''La Base'' zips through an overview of savory cooking, then switches to baking and desserts. But while most general cookbooks would stop there, ''La Base'' plunges onward into contemporary cuisine; the last 20 pages include instructions on how to cook fennel sous vide (slow-simmered in a vacuum-sealed pouch) and recipes for of-the-moment constructions like foie-gras foam and savory jellies, among them the dish that made me decide I had to hand over the 23 euros: Sea Water Jelly.

Jellies, along with foams, purées and powders, are an obsession of the new molecular gastronomy, which focuses on the physicochemical aspects of food -- temperature, texture and physical structure. Proposed as a condiment for fish or seafood, Sea Water Jelly is, essentially, salted water thickened with gelatin and turned bright blue with a splash of Curaçao. It's a breezy frippery that welcomes molecular gastronomy into the mainstream.

I called Grant Achatz, the chef at Alinea in Chicago, to tell him about it. Blessed with a restless intellect and a pitch-perfect palate, Achatz is one of the key American practitioners of molecular gastronomy, along with Wylie Dufresne at WD-50 in New York and José Andrés of Minibar in Washington. He found the Sea Water Jelly entertaining because of the implication that the movement was starting to cross over to the home, and because, well, it's funny.

For some time now, Achatz has been experimenting with jellies to create ''solid sauces'' -- thin, flavorful liquids given mass and viscosity through a variety of techniques. The sauces evolved, he explained, from a recent period using vegetable purées to accompany meats and fish. ''I thought it would be interesting to turn a sauce into a purée,'' he said. ''To make a purée, you just stick a solid in the blender. The challenge was turning a liquid into a purée. To purée a liquid, I realized I had to turn it into a solid and then purée the solid.''

To create his solids, he works with different gelling agents, from gelatin to seaweed extracts like agar and carrageen. Achatz's first solid sauce was a yuzu fluid gel, which he made by heating the fragrant citrus juice with agar, cooling it to set, then puréeing the resulting jelly into a puddinglike sauce, which he served with sugar snap peas, yogurt and ham.

With solid sauces, Achatz explains, ''flavor release'' is key. Jellies are essentially flavor elements suspended in a neutral medium. Bound in their carrier matrix, the flavor molecules are relatively inaccessible to the taste buds, so the jelly is first experienced primarily as texture. At a certain temperature, different for each agent, the molecular mesh relaxes and the flavor is released. With gelatin, this occurs at body temperature; in Achatz's Mussel Cream With Mint and Chamomile Jelly, the herbal flavor blooms in the mouth as the gelatin melts.

For many sauces, Achatz uses agar, which remains firm at body temperature; puréeing the set jelly keeps the sauce thick while allowing flavor release. The resultant liquid gel is intensely flavored but thick and glossy, like his jet black soy liquid gel, which he recently served as part of a casually deconstructed Thai salad with Kobe beef, melon and cucumber.

Achatz has developed a recipe for home cooks of an experimental bent. His take on crab salad uses the natural starches in sweet corn as structural elements in a solid sauce for crabmeat with coconut curry and lime: Achatz freezes the corn sauce in thin sheets, then drapes rectangles of it over the other components. As the sheet thaws, it encases the food, lacquering it so that every bite is sauced perfectly. Variability in the corn's starch content means this sauce may require a little coaxing and some prayer.

The reward for experimenting with this technique is entree into the world of molecular gastronomy, but who knows? It may even lead you to the creation of the next Sea Water Jelly.. . .

Crab Salad With Corn-Sheet Sauce

8 ears yellow corn (or 7 cups frozen kernels)
3 tablespoons unsalted butter
3 tablespoons sugar, plus more to taste
2 teaspoons kosher salt, plus more to taste
Cooking-oil spray
1/2 cup coconut milk
1 tablespoon mild curry powder
1 avocado, peeled, cored and cut lengthwise into 1/3 -inch slices
1 lime
40 small or 20 large basil leaves
8 ounces crabmeat, preferably large leg sections, cleaned
1/2 red bell pepper, cored and cut into 1/8,-by- 1/8,-by-1 1/2 -inch strips.

1. Cut the corn kernels from the cobs. Set aside 1/4 cup for the garnish. Over a bowl, scrape each cob with the back of a knife to release the juices.

2. Place the kernels and juice in a blender. Blend briefly on low to break up the corn, then on high for about 2 minutes to make a purée. If using frozen corn, add 1/4 cup water to the blender. (If the corn will not blend, stop the machine and loosen the kernels with a spoon before trying again.) Strain the purée through a sieve placed over a saucepan and lined with 3 layers of fine cheesecloth. Press on the solids with a ladle to release the juices, then wring out the corn-filled cheesecloth to extract the remaining juices. You should have about 2 1/2 cups corn juice.

3. Add the butter, 2 tablespoons sugar and 1/2 teaspoon salt to the saucepan and place over medium-low heat. Season with more sugar and salt to taste. Whisk continually until the butter melts, then stir until the sauce lightly coats the back of a wooden spoon, 12 to 16 minutes. Transfer to a heatproof container and cover with plastic wrap to cool.

4. Whisk the cooled sauce until smooth. Cover an 8 1/2 -by-12-inch rimmed cookie sheet with wax paper. (Make sure the cookie sheet fits in the freezer and that its surface is perfectly flat.) Spray the wax paper with cooking oil, then pour the sauce over it in a thin sheet (about $(7$)2-inch thick). Drain off the excess sauce and place the sheet in the freezer. Repeat with a second cookie sheet.

5. Combine the coconut milk, curry powder, 1 tablespoon sugar and 1 1/2 teaspoons salt in a small saucepan. Simmer for 3 minutes, stirring constantly. Remove from the heat and chill.

6. Cut the avocado slices in half horizontally. Zest the lime, then peel and segment the lime and cut the segments in half horizontally. If using large basil leaves, tear them into small pieces.

7. Cut each of the frozen corn sheets into 4 3-by-8-inch rectangles, slicing through the wax paper. Return the cookie sheets to the freezer.

8. To serve, arrange a few pieces of crabmeat, avocado and red pepper flat in a 2-by-6-inch area on each of 8 plates. Do not pile the ingredients. Top each salad with a few corn kernels, a little lime zest and basil. Dab with a touch of coconut sauce. Remove a rectangle of corn sauce from the freezer. Peel the wax paper from it as you lay it directly over a salad. Work quickly -- the sauce melts rapidly and will stick to the wax paper unless frozen solid. Do not worry about breaks in the sheet. As the sheet thaws, the sauce will envelope the ingredients below. Garnish with corn kernels, lime zest and basil. Repeat with the remaining 7 salads. Serves 8. Adapted from Alinea in Chicago.

NOTE: Excess sauce can be used to practice removing the wax paper from the corn sheets. And if you can't quite get it right, the sauce is also delicious spooned over the salad at room temperature.