Chefs embrace new technique to concentrate and extract foods’ essence
By Heidi Knapp Rinella
It’s the Holy Grail of food preparation: extracting maximum flavor as naturally as possible.
Even though people have been cooking for thousands of years, chefs continue to discover new techniques. One of the latest is called cryoconcentration.
“You hear the name, you think about chemicals — liquid nitrogen and all these things,” said Wilfried Bergerhausen, until recently executive chef at Le Cirque at Bellagio. “It’s not chemistry; it’s science.”
In May, Bergerhausen and Christophe De Lillis, executive chef of Joel Robuchon at MGM Grand, joined a select league of about a dozen chefs who have traveled to the Culinary Research & Education Academy in Washington, D.C., to learn the technique from culinary pioneer Bruno Goussault. Goussault is widely credited with inventing the sous vide technique of cooking vacuum-packed foods at low temperatures for extended periods.
“He has been working with this for a very long time — over 40 years,” Bergerhausen said. “He is the person who kind of drives this technique.” Extraction, Bergerhausen said, is a natural extension of sous vide.
With the gentle sous vide process, foods’ juices and other sources of flavor are preserved by cooking in vacuum-packed plastic. Extraction is about flavor preservation as well, but in a different way.
“Extraction is a technique to transfer flavor from a solid to a liquid,” Bergerhausen said.
Generally, to get concentrated flavor, cooks use heat to caramelize surfaces and reduce sauces.
“Because of the heat when you do this, you kill some flavor molecules,” De Lillis said. “We don’t use the heat to reduce the product, we use the cold.”
Bergerhausen uses carrots as an example. Photosynthesis makes the outermost layer of the root the most flavorful, yet it’s often discarded before cooking.
“Let’s say you have carrot peelings, mushroom stems or anything that you can think of, mostly on a vegetable basis,” he said. You cook it in water for an extended period, and all the flavor goes into the water.
“Your solid has absolutely no taste anymore. All the taste is in the liquid, and that’s where the cryoconcentration comes into play. Cryoconcentration is a technique of reducing and concentrating that flavor, but instead of steaming or reducing something, we get rid of the water by freezing it.”
The liquid is frozen and granulated in a special process. The flavor then is drained from the ice granules, similar to the way snow cone syrup pools at the bottom of a paper cup.
“We take out the water, and just be left with the concentrated flavor,” Bergerhausen said.
To intensify the effect, the technique can be repeated.
“You can do it five, six, seven times — you will be left with something that is extremely concentrated, almost a syrupy consistency,” he said.
Cooks can also blend the concentrated flavors together, using, for instance, five parts carrots, two parts mushrooms and other ingredients. The resulting mixture can be incorporated into a sauce or another part of a dish. De Lillis said he cooks white button mushrooms for 12 hours at 72 to 90 degrees Celsius (about 161 to 194 degrees Fahrenheit) and uses the resulting extraction in a risotto.
“It’s quite a complicated process, to be honest,” Bergerhausen said. “The machinery and the manpower that need to be used to do that is quite extensive right now.” It generally takes close to 24 hours.
While Berhausen has yet to add any cryoconcentrated dishes to Le Cirque’s menu, he has given tastings to VIP guests to show the difference in flavor using the new technique and conventional methods.
“I think this is redefining what is going to be the future of cooking,” he said — a sentiment echoed by Culinary Research & Education Academy director James Chen, who said he thinks the technique is “ripe for adoption in today’s kitchens within the next year or two.”
“Working on the flavor, and no waste,” Bergerhausen said. “That’s what every chef wants to do.”