To avoid tears while cutting onions, we tested seven methods. Which one worked best?

Why do we tear up when cutting onions?

This is because onions contain sulfur-containing amino acids like methionine and cysteine. When we cut, the onion’s cells are damaged, and the onion’s enzymes begin breaking down these sulfur-containing amino acids, producing volatile sulfur compounds.

These compounds irritate our noses and eyes, causing us to tear.

7 Methods

Chewing Gum While Cutting Onions: Tear Index 4/5

Chewing gum while cutting onions prevents us from breathing through our mouths, preventing the onion’s volatile sulfur compounds from entering our nasal cavity, thus preventing tears. However, our test found that the tear index was quite high, so it can only be considered a small improvement. However, it can cause a slight odor in our mouths, so I wouldn’t recommend it.

Using a lemon to wipe the knife before cutting onions: Tear Index 2/5

You can cut a lemon in half first, then use the cut edge to wipe the knife you’re cutting onions with. This will help reduce the risk of tears.

This method is quite effective, but while it doesn’t cause tears, it can still irritate your eyes and cause them to water. Also, cutting a lemon every time you cut onions is a bit impractical.

Cutting onions under running water: Tear Index 1/5

This method involves placing the cutting board in the sink, running the tap, and then cutting the onions under running water. This method has been found to be quite effective, significantly reducing eye and nasal irritation.

It seems that the running water removes the volatiles, but the onions will also be completely wet. It’s not recommended for stir-frying.

Refrigerate the onions before cutting: Tear Index 3/5

Refrigerate the onions for 30 minutes before cutting to avoid tearing. In actual testing, refrigerating onions before cutting them did help somewhat, slightly reducing the irritation to the eyes and nose, but cutting them still caused tears.

Chilling onions before cutting: Tear Index 1/5

Putting onions in the freezer before cutting and waiting for 30 minutes before cutting is also a commonly heard method to prevent tears. In practice, I found this to be true. Cutting onions almost never caused tears, and the pungent smell was also less pronounced, making this method quite practical.

Microwaving onions before cutting: Tear Index 4/5

Microwaving onions before cutting is believed to prevent tears, but in practice, I still experienced tears, albeit a slight improvement. Furthermore, microwaved onions become quite hot, making it difficult to cut them immediately.

Cutting onions with swimming goggles: Tear Index 1/5

Cut onions with swimming goggles on to prevent eye irritation and tearing. This trick is actually quite effective. It directly blocks the irritants released by onions from reaching your eyes, which actually reduces the likelihood of tearing. However, it can still cause a slight irritation to your nasal cavity.

Best way

Conclusion: The most effective way to avoid tearing when cutting onions is to refrigerate them for 30 minutes before cutting, cut them under running water, or wear swimming goggles before cutting.