The Food Lab: Better Home Cooking Through Science

At first glance, you may think, what’s the big
difference?
Let me answer your question with a question of my
own: do you care about the flavor of what you put in your
mouth? If the answer is no, then by all means slice your
onions any which way. But if the answer is yes, consider
this: onion cells are not perfectly symmetrical—they’re
longer in the pole-to-pole direction than in the orbital
direct. Hence the direction you slice your onions will
affect the number of cells you rupture and thus the
amount of lachrymators that are formed. We know that
some amount of this stuff is desirable: it makes your
onions taste more oniony, your stews taste more meaty,
your French onion soup sweeter. But too much can be
overwhelming.