Recipe: Compressed Watermelon and Hayden Mango "Yolk"

the appetizer:

In Under Pressure: Cooking Sous Vide, Chef Thomas Keller explores experimental cooking methods, including recipes for Compressed Watermelon and Hayden Mango "Yolk"; Salad of Heirloom Beets, Anjou Pear, Mâche, Candied Walnuts, and Blue Apron Goat Cheese Coulis; and Air-cured Waygu, Treviso Leaves, Compressed Asian Pear and Whipped Pine Nut Oil.

Cookbook

Compressed Watermelon
and Hayden Mango "Yolk"
("Steak Tartare")

Makes 4 Servings

Ferran Adrià, chef-owner of the renowned El Bulli outside Barcelona, brought the technique of spherification, using alginate and calcium gluconate to gel the exterior of a liquid, to fine dining. Ferran"s technique piqued our interest in spherification and its applications. The great team at CP Kelco in San Diego helped us to develop this one, using different hydrocolloids—natural substances that affect the properties of liquids—to achieve similar effects.

When we were looking for a canapé we could offer to vegetarians and vegans, we came up with this play on beef tartare, using the technique of spherification. The compressed watermelon mimics the beef and a ball of encapsulated mango juice replaces the traditional egg yolk. Mango juice actually tends to set up a little on its own, taking on a viscosity that's very similar to that of egg yolk. The dish is finished with a squeeze of lime.

Watermelon

1/4 ripe seedless watermelon, rind removed
Kosher salt
Extra virgin olive oil

Mango "Yolk"

125 grams mango juice
0.8 gram Kelcogel F (see Sources, page 282 of the book)
0.2 gram sodium hydroxymetaphosphate (see Sources, page 282)
30 grams calcium gluconate (see Sources, page 282)
0.4 gram ascorbic acid
75 grams granulated sugar
1/2 1ime
Freshly ground black pepper

For the Watermelon: Place the piece of watermelon in a bag and vacuum-pack at the highest setting. Refrigerate for at least 3 hours.

To complete: Cut the watermelon into a fine dice and then finely mince to resemble tartare. Drain in a chinois or fine-mesh conical strainer. Toss the watermelon with a pinch of salt and a drizzle of olive oil.

For the Mango "Yolk": Put the mango Juice in a Vita-Prep. Place the Kelcogel F and sodium hydroxymetaphosphate on a saucer.

Hold it above the Vita-Prep and, with the machine running on low speed, slowly tap in the powders in steady small amounts until they are all incorporated. Turn to high speed for 2 to 3 seconds, then strain the mixture through a chinois or fine-mesh conical strainer.

To complete: Pour 500 grams of cold water into a deep bowl. Whisk in the calcium gluconate, ascorbic acid, and sugar to dissolve. Put another deep bowl of cold water next to it. Drop a teaspoonful of the mango mixture (keeping it as close to a ball as possible) into the calcium gluconate mixture and let sit for 1 minute. Remove with a slotted spoon and place into the bowl of cold water. Repeat with the remaining mango mixture. Use the best yolks.

Makes 10 "yolks"

At Service: Spread one-quarter of the watermelon in a ring mold on each plate. lift off the mold and top with a mango "yolk." Finish with a squeeze of lime juice and a grind of black pepper.

Note
One-quarter of a small seedless watermelon will yield about 120 grams of tartare, serving 4. You'll get approximately 20 "yolks" from 125 grams of mango juice. It is best not to work with less mango juice. Any unused mango should be discarded. Additional servings can be made from the remaining watermelon.