When do you start using liquid nitrogen in kitchens? At what point is its use? What applications are emerging with it? How to treat it properly? Undoubtedly, one of the most outstanding connoisseurs of the culinary potential hidden by liquid nitrogen is the chef of Argentine origin Martín Lippo, who even created the Nitroschool school in Barcelona two years ago to spread techniques and ideas throughout the world.
Nitrogen is an inert gas that makes up about 78% of the air in the atmosphere. In its liquid state, it has been used for various purposes, either as a refrigerant, as a method of preserving biological samples, for cryotherapy or for freezing food, among other uses. And in kitchen? As on so many other occasions, the sector in general does not know when liquid nitrogen actually began to be used in a restaurant. Martín Lippo has been able to find a first reference to its use in the book Le Nouveau Cuisinier Gascon, published by chef André Daguin in 1981.
As he explains, Daguin started working with this gas in 1976, and in the book he proposes the recipe for White Wine Sorbet, chilled thanks to the application of liquid nitrogen. Curiously, its use remains hidden until in the mid-90s, Michel Bras and Hervé This showed the advantages of preparing an ice cream with nitrogen in front of French television cameras for a group of renowned gastronomic critics.
BORN TO STAY
Starting in 2002, nitrogen became part of the culinary revolution started by Ferran Adrià. The original proposals of chefs such as Heston Blumenthal and Dani Garcia also help its expansion. And in recent years this element has found new outlets beyond offering a visual spectacle. As Martín Lippo emphasizes, “today we have gone from showcooking to appreciate it as a great tool without whose presence many contemporary elaborations would be impossible”.
What techniques are those? Martín points many, from nitrosorbetes to nitro shots, through powders, snow, fruit granules, nitro popcorn, ironing, or liquid ice cream interiors. A whole bunch of possibilities that have arisen thanks also to the industry's commitment to create tools specific for working with liquid nitrogen.
It is a great tool without whose presence many contemporary elaborations would be impossible. Facing the salty world, we find the potential of frozen soups, with a “slash” texture, which can bring a very interesting result to gazpachos, white garlic, or other flavors
As the multifaceted chef points out, “among the last lines of work that we investigated at Nitroschool is that of soft-nitro ice cream, which is an ice cream made without a soft machine and with an overrun, sometimes up to 100%, creating an ice cream -mousse really spectacular in the mouth. We also investigated around the molding of dry meringues. Nitrogen allows the French meringue to be molded and then dried and used. We get unthinkable shapes if you worked with a decoration nozzle ”.
Looking to the future, there are also interesting paths, from liquid, semi-liquid and tender interiors, "which will undoubtedly be part of the future of pre-made frozen dessert". Also the stracciatellas, which can be made not only from chocolate but from raspberry or blackberry, with fruit sorbet dots or other flavors, with curd-type citrus creams or with meringue. And already facing the salty world, we find the potential of frozen soups, with a “slash” type texture, which can bring a very interesting result to gazpachos, white garlic, or other flavors, as in some recipes from the kitchen Korean traditional.
TEN THINGS YOU SHOULD KNOW ABOUT LIQUID NITROGEN
Martín provides us with a decalogue of advice and essential information to successfully approach the use of this element.
- Liquid nitrogen is at a temperature of -196ºC and can cause very serious cold burns on contact. In the kitchen work according to the same protocols as when working with boiling water or hot frying oil. In prolonged exposures to the cold that emanates, and although it is not in direct contact with nitrogen, it is advisable to wear gloves.
- The temperature of foods exposed to liquid nitrogen must also be taken into account, since excessively cold foods could cause burns when eaten or on contact. It is recommended to serve and taste food always at temperatures above -18ºC.
- Liquid nitrogen can only be safely stored in about specific containers called Dewar, special vacuum insulated tanks, a great thermal insulator. In them, nitrogen remains stable and losses due to thermal transmission are avoided.
- There is always a small decrease, even in Dewar tanks. The losses vary according to the size of the tank and the use. The fuller the container is, the lower its evaporation. A 20-liter tank can hold nitrogen for about 4-5 weeks, and a 30-liter tank for 5 to 6 weeks.
- The tank can be left anywhere in the kitchen, the important thing is not to move it. The more the tank moves, the more evaporation.
- Under no circumstances should it be hermetically sealed. It would cause the explosion of its continent due to the pressure it exerts, because when it passes from the liquid to the gaseous state, it expands, increasing its volume by almost 700 times.
- For the same reason you must work in ventilated places or with the smoke extraction switched on. In this way it will be avoided that, when expanding, this gas displaces the amount of oxygen available in the air, generating a risk of suffocation.
- Liquid nitrogen can also be seen as a tool that provides Economic benefits. Faced with the expense of a butter maker for a restaurant, a Dewar tank costs about 800 euros. In addition, with it you can not only make ice cream but many other techniques.
- Not all materials are used to handle it. Must betting on metals, by borosilicate (Pyrex) or by polystyrene.
- At an organoleptic level, the results with its use improve if you bet on incorporate some fat into the mixture or recipe to freeze. You can also bet on elaborations with enough air, type foams or mousses. In this way the icy block feeling is avoided.
Original article in: Know and Taste