Dry Ice In Cooking

Dry ice was first defined in 1925.  Dry ice by definition is the solid state of carbon dioxide, in a crystallization. We call dry ice “dry” because dry ice cannot melt into a liquid (another bonus to using it in food prepartation). Sublimation is the transitory process in which a solid turns directly into a gas; dry ice sublimates into carbon dioxide gas.

Dry ice works like this: first, carbon dioxide gas is compressed into a liquid form, removing an excess heat during the step. The gas then becomes a liquid at a pressure of approximately 870 pounds per square inch at room temperature. The liquid carbon dioxide can then expand. As a result, the temperature decreases, which causes some of the carbon dioxide gas to freeze into an icy powder. The last step is a final compression in which the powder is compressed into dry ice!

Dry ice has been a molecular gastronomic tool that’s been implored for over 100 years. And while the gimmick of dry ice in combination with food is nothing new, more and more culinary professionals have been gravitating towards the technique making it a more and more a common practice. In terms of food preparation, dry ice can speed up the process exponentially. Using dry ice can rapidly freeze anything from a liquid to a solid, so in cooking shows where time is a key component contestants often use dry ice to make their food preparation run more quickly. For example, it can freeze ice cream or fruit into a sherbet in minutes. Dry ice can also be especially helpful in power outages because it has the ability to keep foods safe for a longer period of time, whereas refrigerators only have the ability to keep food at a safe temperature for no more than 4 hours.

However, there are many precautions that come along with using dry ice. Since, dry ice boils at approximately -109.3 and -78.5 meaning it’s extremely cold. To put it in perspective, it’s way farther from room temperature than putting something in a fryer. Other precautions include not allowing the dry ice to come in contact with ones skin, staying away from the steam produced from the use of dry ice (aka making sure that the room you’re using is ventilated), and not allowing the dry ice to come in direct contact with food. These is because of dry ice’s extremely fast freezing point (meaning it can burn you really easily because of how cold it gets) and the fact that it emits carbon dioxide means its toxic to consume in large quotients.

Even with all of these precautions, I still think that dry ice is in the end just a tool. Knives are dangerous, but a chef must learn how to appropriately cut with them so that they don’t harm themselves. If a chef learns how to safely use dry ice I see nothing wrong with dry ice being used in preparation as long as it’s not directly touching the food and being given proper care and attention. Otherwise, it seems absolutely safe for human consumption. Plus, dry ice can produce fast and beautiful cooking techniques that you wouldn’t otherwise get from using a simple freezer. However, I’m definitely not encouraging people to start using dry ice in their own homes. It’s still if the precautions aren’t followed and you wouldn’t want that kind of toxicity in your living space.