Onions add flavor to almost every savory recipes. In the flavor world, they’re as reliable as they come. But when you slice through an onion, the enzymes and sulfenic acids that are naturally present combine to produce gas that can irritate the sensitive tissue of the eyes. In short: waterworks.
Fortunately, there are ways for getting around this emotional rollercoaster. While you can’t prevent the gas from releasing when you cut onions, there are some tricks that can help reduce or eliminate tears.
Sweet onion varieties like the Vidalia have more natural sugars and less of the enzymes that produce tear-invoking gases. Many cooks prefer using sweet onions in many recipes, as the taste is mellow and blends easily with other flavors.
Spring & Summer Beats Fall
Onions harvested in the fall will be more pungent and tart than the same variety harvested in the spring or summer. Onions harvested in the cooler months of the year hold less water and have a more concentrated, intense flavor, as well as those troublesome enzymes and acids that induce tears.
You can purchase and store spring and summer onions for many months if done properly — any cool, dry, and dark area will do. Consider a garage, pantry, root cellar, or the lower drawer of your refrigerator set on a dry humidity setting. This doesn't mean you can't buy an onion in the winter. It just means you should be more cautious as you are cutting them and realize it is likely to be stronger.
Keep Those Gases Away from Your Eyes
It sounds like an overly-simple solution, but anything you can do to keep the gases from reaching your eyes will keep the tears (and the burning sensation) at bay.
- Always turn the cut side of the onion away from your face.
- Turn a fan on to blow the fumes away from your face as you slice the onion.
- Wear eye protection. A simple pair of glasses can prevent the gases from reaching your eyes (we legitimately have a pair of “onion goggles” in the Tablespoon Kitchens)
- Chop the onion in a food processor to contain the gases. Be prepared when you remove the lid, though—turn your face away from those gases!
- Fresh lemon juice can help dissipate the smell of a cut onion. Also try wiping your knife with lemon juice before cutting the onion. Some swear by this simple strategy to prevent crying.
- Some claim that it helps to cut the onion under running water. You'll have to try and see if that works for you. Take care not to cut fingers instead of the onions, though!
The good news is that you'll build up a tolerance to onions over time. The more you handle onions, the less likely you are to cry over them. In the meantime, take some easy precautions and you can add them to whatever recipes you choose without hesitation.