“Just chew gum while you cut.” That was my aunt’s advice. It did not work. I stood in my kitchen, jaw working furiously, tears streaming down my face, dicing onions for Sunday chili. I looked completely insane.

So I tested everything. All the internet tricks. Here is what actually stops the tears — and what does not.

Why Onions Make You Cry

Cutting an onion releases a compound called syn-propanethial-S-oxide. It floats up, hits your eyes, and forms sulfuric acid on contact. Your eyes produce tears to flush it out. The key to stopping the crying is stopping that gas from reaching your eyes.

Method 1: Sharp Knife (Works Best)

A dull knife crushes onion cells, releasing way more gas. A razor-sharp chef’s knife slices through cleanly with minimal cell damage. I tested this side by side — dull knife versus freshly sharpened. With the sharp knife, I diced three onions before my eyes even tingled. With the dull one, I was crying by the second cut.

Method 2: Chill the Onion (Works Well)

Pop the onion in the freezer for 10-15 minutes before cutting. Cold slows the chemical reaction that produces the tear gas. Do not freeze it solid — you just want it very cold. This also makes the onion firmer and easier to slice cleanly.

Method 3: Cut Near a Fan (Surprisingly Effective)

Point a small desk fan across your cutting board, blowing away from your face. The fan pushes the gas away before it reaches your eyes. This is not elegant but it works. I use this method when I am prepping pounds of onions for French onion soup.

Method 4: Leave the Root End for Last

The root end of the onion contains the highest concentration of the tear-inducing compounds. Cut off the stem end first, peel, then slice, leaving the root attached until the very last cut. This alone reduces the gas release significantly.

I have also tried: goggles (effective but ridiculous), bread in the mouth (myth), cutting under water (effective but dangerous with a sharp knife), and lighting a candle nearby (myth — tested three times).