BENGALURU : The cryogenic cooking or nitro-cooking is a culinary concept that uses liquid nitrogen to freeze natural ingredients and transforms them into ice creams, sorbets, slashes and granitas. This is not a new concept. Science teachers have been making ‘instant ice cream’ for years for the delight of their students. In fact, liquid nitrogen ice cream was invented by Agnes Marshall in 1901.Nitrogen is an inert gas that makes up about 78 per cent of the air present in the atmosphere. It is used for many purposes, such as refrigerants, preservation of biological samples and cryotherapy or freezing of food.
Liquid nitrogen is not toxic in any way. It is not flammable, it is tasteless, odourless and very cold with a temperature of -196ºC /-321ºF.Liquid nitrogen is a distilled form of nitrogen and since the boiling point of nitrogen is really low, liquid nitrogen, being extremely cold, is used to freeze food instantly. The frozen food created by liquid nitrogen has high creamy consistency.
I have been working with liquid nitrogen since 2005, learning and developing new culinary techniques and recipes with it, that pushed me to create Nitroschool in Barcelona in 2015. Students from all over the world came to the school to learn. Nowadays, you see chefs using liquid nitrogen for all kinds of competitions.
In the lab, we developed most of the existing techniques with this tool-ingredient, and we are constantly investigating. Some techniques are Nitro-overrun, Nitro-dots, Frozen double lollipops and Nitro-popcorn.
The biggest challenge we faced was to change the myth about how dangerous liquid nitrogen is.
When you give an opportunity to a child to prepare tea or cross a street, these common and simple things could also be dangerous if they are not taught how to do it right. It is the same with liquid nitrogen. Everybody must be trained before using liquid nitrogen. Otherwise, it could pose a could be at risk.
Nowadays, fortunately, many culinary chefs and pastry chefs around the orld use liquid nitrogen in their kitchens and they explain the way of using it to the other chefs.
Guide to use liquid nitrogen
■ Liquid nitrogen is at -196ºC and can cause very severe cold burns on contact. ■ It is advisable to wear gloves.
■ The temperature of foods exposed to liquid nitrogen should also be taken into account as they might cause cold burns when tasted or on contact.
■ Liquid nitrogen, in its liquid form, is not safe to eat. However, once it has evaporated the food, it is perfectly safe to eat.
■ We recommend serving and tasting food always at temperatures above -18ºC.
■ It is only possible to store liquid nitrogen safely, in specific containers called Dewars, which keep it stable and avoid losses by transmission.
■ Under no circumstances, it should be hermetically sealed, or it can cause the explosion of your continent because of the pressure exerted, because when it converts from liquid to gaseous state, it expands, increasing its volume by almost 700 times.
■ For the same reason, work must be done in ventilated areas or with smoke extraction turned on, to prevent the amount of oxygen available in the air from being displaced and reduce the risk of suffocation.
■ Go through the manuals provided by nitrogen suppliers.
– Chef Martin Lippo
The chef was in the city for a master class on molecular gastronomy at Academy of Pastry Arts.