Try It Yourself: Cryogenic Cuisine
The goal of this experiment is to allow you to explore how cold temperatures can be used to prepare foods in ways that might surprise, shock, and satisfy you and your taste buds. Nathan Mhyrvold, one of the authors of Modernist Cuisine, writes[1]
"Since man’s discovery of fire, cooking has been mainly a process of subjecting food to high temperatures that chemically alter its color, taste and texture. But the invention of cryogenic technology has handed chefs an exciting new tool—liquid nitrogen—for transforming food in fun and surprising ways. In our culinary research laboratory, we use this ultra-cold liquid to cryo-poach oils, cryo-shatter cheese, cryo-powder herbs and cryo-grate meat. It is great for making instant ice cream and perfectly cooked hamburgers. For many years the coldest substance chefs had ready access to was dry ice (frozen carbon dioxide), which sublimates directly to CO2 gas at –109 degrees Fahrenheit (-180 C). Although dry ice has some interesting culinary uses, its solid form limits its utility. Nitrogen boils at a far colder temperature: –321 degrees F, about as many degrees below zero as hot fryer oil is above zero. And because nitrogen melts before it vaporizes, unlike carbon dioxide, it is relatively easy to store as a liquid and pour over food or into a bowl. Because its viscosity is about one-fifth that of water and it has relatively low surface tension, liquid nitrogen flows rapidly into nooks and crannies in foods, such as hamburger patties, that have rough or irregular surfaces. The cooks at our lab use it to make fantastic burgers that are first slow-cooked to medium rare, then dunked briefly in liquid nitrogen to freeze a thin layer of the exterior and, finally, deep-fried. The deep-frying creates a perfect brown crust and thaws the frozen layer but does not overcook the interior."
Speed is crucial for freezing foods without damaging their texture. In general, the faster the freezing process, the smaller the ice crystals and the less they disrupt the cellular structure of the food. Since the 1970s chefs have used liquid nitrogen to make super smooth ice cream. More recently, chefs have started using it to flash-freeze delicate foods such as foie gras. Because liquid nitrogen is a relatively new addition to the kitchen, many other applications of this versatile fluid still await discovery.
In this section of the lab, you will explore three cold substances: ice water or snow, dry ice, and liquid nitrogen that can be used in cryogenic cooking and cooling.
CAUTION: Burns can be caused by exposure to extremes of temperatures. Insulated gloves and goggles should be worn for this lab.
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Equipment |
Ingredients |
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Insulated gloves large mixing spoons thermometer small pot goggles
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Ice or Snow Dry ice Liquid Nitrogen 1 cup pure Maple syrup vegetable oil to rub on edges of pot pickles as palate cleansers |
MODIFIED FROM the VERMONT Maple Syrup COOKING BLOG
http://blog.dakinfarm.com/2011/03/making-serving-sugar-on-snow-at-home/
- Turn on the hot plate on to preheat, then proceed to wash your hands
- Pour one cup of pure Vermont maple syrup in a medium saucepan, Grade A Medium Amber is the best stock for candy making.
- Use a paper towel to coat the rim of the pot with a small amount of vegetable oil so the syrup will not boil over and to keep the boiling liquid low in the pot.
- Heat the liquid in the pot carefully over medium heat. With a digital thermometer, monitor the temperature of the syrup while it is boiling. The syrup is ready when it reaches exactly 233o F. At this point it is the correct “sugar on snow” consistency.
- Remove heated and thickened maple syrup from heat source and pour into smaller Pyrex measuring pitcher. Cool briefly (5 min) so that it will not melt the snow as quickly.
- Gently pour* about 1/3 of the thickened maple syrup over crushed ice or snow in thin ribbons (i.e. not in a big blob). When heated to the proper temperature, the syrup will form a taffy when it hits the cold snow.
- Next gently pour 1/3 of the heated syrup over the dry ice using a similar technique (in ribbons).
- Finally pour the remainder of the still heated syrup into the liquid nitrogen using a similar technique (in ribbons).
- Compare the three candy products, with respect to their
color, degree of elasticity, clarity, brittleness, and taste (let the liquid
nitrogen candy warm up a bit first or you may frost your tongue). Pickles can be used as a palate cleanser.
*Note: once the syrup is heated, it is best to pour it over snow without agitating it. If a ladle, cup or spoon is repeatedly dipped in the thickened syrup, the syrup will crystallize
Exp B: Liquid Nitrogen Ice-Cream and Sorbet
As Dean of New Students from 2010 to 2014, I made liquid nitrogen ice cream in each of the seven first year dorms. What follows is the recipe that has been field tested to about 1000 Amherst College students.
Dean’s Ice Cream
2 quarts half and half
1 quart light or heavy cream
1 cup sugar
1 T vanilla
5 L of liquid nitrogen
Mix the liquid ingredients together with the sugar to blend. More sugar can be added to taste. Once the sugar is dissolved, the liquid should be stirred continuously as the liquid nitrogen is added until thickened (about 5 minutes). Serve immediately.
Note: Fresh fruit sorbet can be substituted for the ice cream mixture
CAUTION: Liquid nitrogen can cause burns if not carefully handled with insulated gloves and eye protection. Under NO CIRCUMSTANCES should you attempt to consume liquid nitrogen – attempts to do so have resulted in severe injury
http://newsfeed.time.com/2012/10/09/woman-loses-stomach-after-drinking-liquid-nitrogen-cocktail/
CRYOGENIC CUISINE
TASTING
AND DATA SHEETS
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Cryogen |
Molecular Structure |
Temperature |
Phase Change |
Comments |
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Ice
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Dry ice
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Liquid Nitrogen
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Cryogen |
Appearance and Clarity |
Elasticity … Brittleness |
Taste |
Comments |
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maple sugar on snow
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maple sugar on dry ice
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maple sugar on liquid nitrogen
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