How to Cut the Onion

Toward the end of Henrik Ibsen’s play “Peer Gynt,” a saga of the self under siege, we find Gynt deep in the forest, peeling a wild onion. He compares his many selves—cheat, shipwreck survivor, liar, prophet, betrayer, gold-digger—to the onion’s layers.

Gynt finally exclaims, “What an enormous number of layers! Are we never coming to the kernel?

“Ah,” Gynt finds, “There isn’t one! All the way into the innermost bit, it’s nothing but layers, smaller and smaller.”

Ibsen means to say that, however much self-seekers peel back the layers of their selves, what they find is nothing. Not a rotten core; no core at all.

Not so quick there, Mister Ibsen. Looked at closely, the center of a real onion sports two stem buds by which, if planted, comes the second year’s growth. The core of an onion is the beginning of a new life.

Remember that at the next meeting of your support group.

Those stem buds, positioned upwards from the root end, also indicate to us cooks how best (and less tearfully) to prepare and cook the onion.

It matters much if you cut an onion “pole-to-pole” through both its stem and root ends versus if you cut it along its “equator,” the opposite direction by 90 degrees.

First, the tears. As a defense mechanism against nibbling pests or gnawing animals, each of an onion’s cells contains sulfur, taken up from the soil while the onion grows. The onion also makes an enzyme that, in combination with the sulfur, catalyzes it into biting sulfurous compounds. The enzyme and the sulfur mix whenever the onion’s cell membranes are broken, for example, when cut open by the edge of a chef’s knife. (Especially a dull blade. Lesson: Use a very sharp knife edge to cut the onion.)

Volatilized into the air around the cutting board, the sulfur-enzyme amalgam converts some of the liquid in our eyes into sulfuric acid. Ouch, we burn, we cry.

But the cells of an onion, just like those stem buds, are longer pole-to-pole than in the perpendicular direction. If an onion is cut pole-to-pole, the knife ruptures fewer cell walls than if the onion is cut radially, along its equator. Polar expeditions on an onion mean fewer (though not an absence of) tears.

Also, cutting pole-to-pole results in more uniformly sized slices, both in width and length. For certain cooking preparations using onions, such as the French onion soup linked below, this means more manageable and uniform cooking and browning.

Nothing wrong with onions sliced along their equators, just a difference. What would a burger do without its slice of red onion? Or a hot dog without dice from the same cut of a white onion? Well, they wouldn’t stand for those pole-to-pole slices, thank you very much.

A cook’s note about those tears: Advisories abound about preventing tears while cutting onions. What works for me is to light two candles and place one on either side of the cutting board, hence burning off many of those volatilized sulfur-enzyme fumes.

The kitchen countertop becomes a sort of altar, which occasionally is both comforting and inspiring.

Recipes using lots of onions on this site:
- For Gratin of French Onion Soup.
- Three Ways to Cook the Vidalia Onion.
- More about different sorts of onions, in “All About Alliums.”
- Onions as part of Mirepoix, Sofrito, and the Cajun “Holy Trinity.”