[lost_name]

It seems it's more nuanced. Try the following searches:

  how long does it take to caramelize onions
  how long does it take to caramelise onions (note the typo)
  how long to caramelize an onion (not a typo but still wrong)
  how long to caramelize onions

[linuskendall]

Replacing the 'z' with 's' is not a typo, though.

[ConceptJunkie]

Several years ago, a coworker pointed out that an article spelled "organization" with an "s" instead of a "z" and wondered why such an obvious mistake would pass an editor.

I pointed out that that's just the British spelling. Everyone in my group was amazed that I would know such a thing. It was an eye-opening moment... for me.