You pick up the knife. You approach your favorite kitchen table and proceed to cut an onion to fry or perform any standard culinary act. Suddenly you surprise yourself with eyes flooded with tears and an unparalleled stinging in the eyelids. Everyone knows the power of the onion to cause human tears. An unpleasant inconvenience that frightens many people and triggers large doses of contempt and revulsion towards one of the most used condiments in our gastronomy.
But why doesn’t anyone wonder what’s going on? What kind of black magic makes it possible for a simple cut of the onion to make us cry? more than do the income statement? On the other hand, you have surely noticed that this effect decreases when we use onion that has been previously stored in the refrigerator. Does the temperature influence the tear-producing power of the onion?
Blame it on the chemistry
That cutting onions makes us cry responds to an interesting phenomenon that occurred inside the onion itself. Taking the counter to Despistaos: it is not physics, but it is chemistry. Specifically, the blame for this tearing event is attributed to two enzymes: tear factor synthase and allinase. Both, respectively, are released from inside the onion when you cut it. When they come into contact generate sulfur-type compounds such as thiopropanal sulfoxide. This gas, which grammatically seems like an insult, is actually a component that is very rich in sulfur. And do you know what is also very rich in sulfur? Sulfuric acid. Yes, it sure sounds like you. And not exactly for the better.
When thiopropanal sulfoxide gas rises and comes into contact with the water in our eyes something creepy happens. Precisely, sulfuric acid is formed from that sulfur. Faced with this dangerous event, our eyes generate tears with a protective function. Yes, the simple act of crying protects us because it dilutes these sulfur compounds and they do not allow the blood to reach the river —or that the sulfuric acid burns our eyes, rather—.
The million dollar question is how the hell can we protect ourselves against this acid event. Who more and who less has faced the culinary abyss on some occasion, having to endure how two tears fell on their favorite salad. Calm. Because from now on, crying while cutting onions is going to end. Luckily, there are certain homemade tricks that allow us to minimize I cry onion so that we can prepare our appetizers without much concern. there they go
Cold and water so as not to cry with the onion?
As we mentioned at the beginning of the text, temperature plays a crucial role in the enzymatic activity of the onion responsible for crying. In this sense, lowering the temperature before cutting in the fridge can be very useful for minimize the synthesis of sulfur gases. Still, it won’t be a miracle cure. We can obtain an easy comparison when we have leftover onions and keep one of its halves in the refrigerator. Later, when cutting that onion, we will notice that it does not make us cry as much as if it were fresh.
Other recommendations on-line They suggest cutting the onion in half and soaking it in cold water for a few minutes. In this way we will achieve an effect similar to that of the refrigerator, only that, in addition, in this case the water penetrates slightly inside the onion and can soften its texture. We must bear in mind that all these ninja-culinary techniques also inevitably diminish the flavor of the onion: this depends on these sulfur compounds.
A sharp knife is always better
In turn, having a brand new sharp knife will always be better than resorting to the Albacete knife given by your father-in-law. The main reason is that, with a clean cut, we will be minimizing the breakage of the cellular structures of the onion. Consequently, the release of enzymes responsible for creating sulfur compounds will be less.
Another trick that works is wet the knife slightly after each cut, in order to dilute the amount of sulfur gas that appears. However, it can be counterproductive in some recipes. Same as him guy which recommends cutting the onion in a container of water. With this we achieve that the gases do not emanate towards the surface, but it is still not very practical. Finally, we come across the hack turn on the extractor hood so that the gases from the onion are absorbed from the environment. It may work slightly, but it’s not foolproof either.
Do diving goggles work?
On the Internet it is common to find nonsense galore as far as food is concerned. Tips crazy that promise to improve our culinary experience, sometimes with catastrophic results. As for the onion, it is common to read some scholar who recommends putting on diving goggles to prevent the eyes from watering when subjecting the onion to an imposing crosscut.
In this case, the trick could make some sense, since by putting on large glasses that cover a large part of our face —and eyes— we will prevent the gases released by the onion from reaching our beloved lacrimal glands. However, our nose will remain free, and some gas may also sneak in there, which will slightly irritate our mucous membranes. Secondly, you will make an awful fool with the diving goggles on. You also run the risk of suffering a sudden cut by minimizing your field of vision and ending up in catastrophe. It seems like a better plan to cry over an onion than amputate a finger. Although you choose.
Another popular trick says that place onion skin on the head it is useful to stop the expansion of tears, but it lacks all truth. It certainly sounds pretty ridiculous. Finally, there is a grotesque rumor circulating that states that if we stick out our tongue cutting onions decreases the chances of crying. According to this crazy theory, our saliva reacts with part of the sulfur gas, minimizing the amount that reaches the eyes and, therefore, reducing the secretion of tears.
Nevertheless, no scientific evidence —or common sense— that supports this infamous lingual conspiracy. The dispersion of the volatile substances that are released when cutting onions takes place in all directions, and not in a directed way on the tongue. Therefore, there is no humanly possible way to prevent the gases from reaching our eyes. Okay, yes. With diving goggles. But we have already debunked that theory previously. In short: better choose a quality knife and stop talking nonsense that you can read on the Internet. This text is an exception, of course.
Pictures | Freepik
In Vitónica | How to understand food labeling step by step and get it right in your next purchase at the supermarket