THE GREAT COLD: LIQUID NITROGEN AND ITS CULINARY USE
The Great Cold technique involves the use of liquid nitrogen in the kitchen. In recent years it has become increasingly popular, even for home cooking
A pot boils at 195.82 ° C. Below zero. – 195.82 ° C: it is the temperature of liquid nitrogen, which for some time has begun to catch on in the kitchen and does not end with the preparation of sorbets in front of customers, including smoke and special effects. The name of this technique? Great Cold.
What is nitrogen
Before talking about the technique called “Great cold,” it is good to clarify the nature of nitrogen. It is a gas that contains the air we breathe every day. Indeed, to be precise, nitrogen (N2) composes 78.09% of the air, while oxygen is present only for 20.95%.
The function of nitrogen in our body is inert. In short, it does nothing: it does not contribute to any physiological process; it does not react; we do not accumulate it. We exhale it directly, putting it back into circulation: its only usefulness, however, is decisive, because it allows us to take the right amount of oxygen with every breath.
Liquid nitrogen and the Great Cold in the kitchen
But in the kitchen, nitrogen is used in liquid form and, consequently, at a very low temperature. Its quality is to rapidly cool everything that gets into contact with it, allowing the aromas to be extracted efficiently.
Besides, the peculiarity of the nitrogen is to form ice crystals much smaller than those obtainable with traditional freezing. Consequently, if you were to taste the classic sorbet made with nitrogen, you would notice that the mouth does not freeze, although the ice cream is still at tens of degrees below zero. It is also a phenomenon that can be found in cryotherapy, where athletes or women who want to rejuvenate their skin immerse themselves in nitrogen tanks for several minutes.
Returning to the example of sorbet created with liquid nitrogen, how is it possible that an element at almost 200 ° C below zero does not freeze the mouth, and indeed does it less than normal ice cream? Thanks to the micro-crystals. These, as they are extremely reduced, take little heat from the tongue to the benefit of the taste of the food (as you know, food that is too hot or too cold loses its flavor).
As a result, nitrogen is used both for its scenic qualities (the famous smoke produced when preparing food) and for its ability to enhance flavors. Also, by cooling ultra-rapidly, it allows for incredible creations, solidifying creams or allowing the presentation of frozen foods outside and boiling inside.
In short, nitrogen enhances the organoleptic characteristics of some foods and allows us to know and appreciate new tastes and textures.
Nitrogen for home cooking
Now, many of you will be wondering: can I also use it at home? Yes, you could, but we would prefer you not to do it and rely on professionals. However, we don’t hide the existence of nitrogen containers that can be purchased from specialized and non-specialized retailers, as well as the possibility of buying nitrogen (liquid or not).
Watch out: each container has a cap that lets the gas escape, not yet in liquid form. So be careful, because the air becomes asphyxiating if the concentration of nitrogen exceeds 88%. It is true that to reach a similar percentage; it would be necessary to evaporate more than 85 liters of nitrogen in a room of 60 cubic meters.
Moreover: the U.S. Food and Drug Administration has pointed out that nitrogen ingestion at -195 ° C is extremely dangerous (needless to say!), and problems have been recorded following the breathing of nitrogen vapors. Unfortunately, similar cases have already been registered. An 18-year-old girl had her stomach removed after swallowing liquid nitrogen.
On the other hand, if you really want to experiment with the Great Cold technique at home, buy adequate and quality tools. Then start with the simplest things, like diving or serving.
Nitrogen ice cream and sorbet
Take a container that can withstand thermal shock like an iron bowl (do not use plastic, glass, ceramic, etc.). Also, be careful when pouring and avoid spills. It is precisely at this point that the liquid begins to boil and makes smoke. Soon afterward, you can immerse a little fruit juice in the nitrogen, and you will notice that it will freeze immediately. Do not taste before the smoke (which is nitrogen in gaseous form) has not completely evaporated.
To prepare the popsicles, instead, proceed filling metal molds with fruit juice (or, if you prefer, with chocolate, etc.). Once done, dip them in liquid nitrogen: we will obtain an iced crust on the outside with a softer, fleshy, and natural heart.
The Great Cold pouring technique, on the other hand, works by pouring nitrogen onto a preparation. This is how the sorbet is prepared: pour the lemon juice into the steel container, then add the liquid nitrogen and, with a spatula, start mixing until you get the proper consistency.
These are only basic indications. On line, however, you can find various courses that will help you learn and use the Great Cold technique.
Where does the word nitrogen come from?
The word nitrogen derives first from the Greek word zoè, and then from the French azotè, which means “lifeless,” being the air component not necessary for the breathing of living beings.
Who did discover nitrogen?
Where is the nitrogen naturally occurring?
When was liquid nitrogen used in catering?
This post is also available in: Italiano (Italian)