Liquid Nitrogen in cooking

Imagine trying to break a raspberry that you froze in the freezer: it would squish, thaw, and turn into a mass of pulp. But with liquid nitrogen you can make little beads of frozen raspberry, or raspberry powder.Because liquid nitrogen is so incredibly cold, it is used to freeze foods, which it can do almost instantly.

But, with the exception of televised competitions where time is a factor, the speed at which liquid nitrogen can freeze foods is not its selling point. Instead, it's how liquid nitrogen freezes foods that makes it such a dynamic "ingredient."

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 cryopoach oils, cryoshatter cheese, cryopowder herbs and cryograte meat. It is great for making instant ice cream and perfectly cooked hamburgers.

Liquid nitrogen also makes hard freezing fast and convenient. Spanish chef Quique Dacosta uses it to solidify Parmesan foam, which he then dusts with powdered, flash-frozen mushrooms to make faux truffles. The stuff also makes quick work of disassembling blackberries into individual drupelets and shattering dollops of oil into tiny shards that thaw in minutes.

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 supersmooth 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.

It is colder than -346 degrees Farenheit. The oil in a deep fryer is about 346 degrees Fahrenheit. Think about that for a second. You really don't want to touch this stuff; it can burn you as seriously as fryer oil -- and so can any bowl or ladle you use while playing with it. So be careful, wear protective gloves, and don't be in a position where it can fall on you if the container of the nitrogen is in breaks from the cold. (Unlikely, but still.)