Cooking 101 question: How can I tell when something is carmelized?

By the color. Onions have a lot of sugar in them, and that is what caramelizes. The onions will acquire a golden-brown hue, like this. Disregard the time instruction, and go for the color, however long it takes.

Unless you are using a nonstick pan, there should also be a “fond” on the bottom—that is, a dark crust that collects and sticks to the pan surface. That’s a good thing, and very tasty.

As for times, it depends a whole lot on (1) how you have cut the onions and (2) how many onions you are trying to carmelize. Onions are mostly water. That water has to evaporate before the onions can get hot enough to where carmelization chemical reactions can occur (iirc about 300 degrees farenheit). So the more onions, the more water you have to get rid of—and the more time it takes.

When they turn brown and perhaps a bit crusty but before they turn burned and black.

Thanks for the info! One more question occurs to me as I am doing this. Should I stir them constantly or let them sit?

Sit them occasionally, every few minutes. Don’t let them sit TOO long or they’ll just blacken on one side.

but not constantly

As they turn tan, stir occasionally, but when they are browner, stir more often or bits will burn. Some of the brown is in the bottom of the pan and you need to stir it into the onions. As they get brown, you can turn the heat down too, to lessen the possibility of burning. The aroma should also clue you. That wonderful, kind of nutty aroma is great. At the slightest scent of burn, take the pan off the fire and stir to see what’s going on. If they aren’t done, stir and put them back, but on lower heat. Then stay with them until they are done. (Your call.) It takes practice.

Amber.