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Frozen Foam Technique
Pastry Chef Rick Billings of L’Atelier de Joël Robuchon – New York, NY

Freezing foam sounds much more difficult than it actually is—but that’s not to say it’s not a textural feat. Pastry Chef Rick Billings of L'Atelier de Joel Robuchon in New York City first created the chilled froth while perfecting his balance of flavor and texture at Clio in Boston following in Alex Stupak’s ingenious footsteps. “With pastry, any ingredient can take on countless forms; frozen, hot, liquid, powder, crunchy, soft,” says Billings.

At an ICC pastry workshop this year, Chef Billings demonstrated his frozen foam technique to an engaged group of students and other chefs, like pastry colleague Johnny Iuzzini and experimental guru Wylie Dufresne. The full dessert he created was called “Le Rocher” or The Rock (see recipe below). Billings says his approach to pastry is to take familiar flavors and present them to people in an unfamiliar way.

The process starts off like a text book foam, but jumps off the page once Billings shoots the frozen mixture from a siphon onto a shallow pan and freezes it in a blast chiller. He shatters the frozen foam into abstract pieces for individual servings. The result is a rough-looking pumice stone that tastes like chewy chocolate ice cream. The first version created at Clio used additives, but his technique evolved to use kuzu starch (or arrowroot powder). It’s molecular innovation using au natural ingredients.

Step 1: Bring equal parts cream and water to a boil with kuzu starch, sugar, and
dry flavoring ingredients.
Step 2: Pour heated cream mixture over chocolate in a bowl and chill to 45°C/113°F.
Step 3: Pour mixture into siphon charger and pump three times.
Step 4: Dispense foam from siphon in an even layer on a plastic-lined pan.
Step 5: Freeze for 8 hours in a blast chiller.
Step 6: Break into pieces and store in freezer.

“Le Rocher” (The Rock)
Pastry Chef Rick Billings of L’Atelier de Joël Robuchon – New York, NY
Adapted by
January 2009
Yield: 1 Serving

“Le Rocher”:
40 grams sugar
40 grams cocoa
40 grams malted milk powder
3 grams salt
20 grams kuzu starch
400 grams cold cream
400 grams water
100 grams gianduja
200 grams milk chocolate

Streusel “Levain”:
250 grams all-purpose flour
250 grams sugar
250 grams butter
5 grams salt
187 grams almond flour
10 grams milk
40 grams fresh yeast

White Beer Sorbet:
200 grams water
100 grams sugar
70 grams atomized glucose
60 grams liquid glucose
450 grams Franziskaner beer
Zest and juice of ½ lemon

Tangerine Sorbet:
260 grams water
280 grams sugar
100 grams atomized glucose
1 kilo tangerine juice

To Assemble and Serve:
Freeze-dried apricots, ground into a fine powder
Delicately flavored herbs, for garnish

For “Le Rocher”:
Mix together sugar, cocoa, malt powder, salt, and kuzu. Put cream and water in a pot and mix in the dry ingredients; bring to a boil carefully while gently scraping bottom of the pot with a rubber spatula. Put gianduja and chocolate in a bowl and strain hot cream over top. Stir to emulsify and then cool to 45°C/113°F. Pour into a siphon and charge three times. Dispense in an even layer into a deep narrow loaf pan lined with plastic wrap. Freeze in a -40°C blast chiller for 8 hours.

Shatter into abstract pieces and store covered in the freezer.

For the Streusel “Levain”:
Preheat one oven to 140°C/284°F, and another oven to 70°C/158°F. Mix flour, sugar, butter, salt, and almond flour until there are pea-sized clumps of butter. Combine milk and yeast until homogenous; then add to flour mixture blending until just incorporated. Spread out on a sheet pan and bake in the 140°C/284°F oven (vented) until dry and golden. Transfer to 70°/158°F oven; bake for 1 hour to finish drying. Process in a Thermomix* until smooth, then pour into a shallow pan to cool for about 8 hours.

Roll 6 gram pieces into “pebbles.” Set aside in refrigerator.

*Because of the butter, the mixture should liquefy while in the Thermomix.

For the White Beer Sorbet:
Bring water, sugar, and both glucose to 85°C/185°F; then cool to 4°C/39°F. Gradually add the beer, zest, and juice and mix thoroughly. Portion into Pacojet beakers.

For the Tangerine Sorbet:
Bring water, sugar, and glucose to 85°C/185°F; then cool to 4°C/39°F. Gradually add the juice and mix thoroughly. Portion into Pacojet beakers.

To Assemble and Serve:
Place “le rocher” in the center of the plate. Arrange two pebbles of streusel around it, followed by one quenelle of each sorbet. Sprinkle a small amount of apricot powder on the tangerine sorbet, and finish the plate with a garnish of herbs and flowers.

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  Published: January 2009