Why do chilled onions make you cry?

Chilling onions does not make you cry more or less than room temperature onions.

Onions release a gas called syn-propanethial-S-oxide (SPSO) when cut or crushed. This gas is what causes the eyes to tear up. The amount of SPSO released is not affected by the temperature of the onion.

Some people believe that chilled onions release more SPSO because the cold temperatures cause the onion cells to rupture more easily. However, there is no scientific evidence to support this claim.

In fact, some studies have shown that chilled onions actually release less SPSO than room temperature onions. This is because the cold temperatures slow down the enzymatic reactions that produce SPSO.

So, if you're looking to avoid crying while cutting onions, it doesn't matter whether you use chilled or room temperature onions. The best way to avoid tears is to use a sharp knife and to cut the onions as quickly as possible.