photo by William Jones (fritish on flickr)
Caramelizing onions means to cook them over low to medium heat until they are very soft and browned. This brings out the onions' natural sugars, and transforms a vegetable which in its raw state is harsh and strong, to a wonderfully sweet and fragrant state.
It takes anywhere from 45 minutes to an hour to caramelize onions, but one taste and you know this time is worth it. I usually set up my laptop nearby and use the time to read or watch videos; you do have to stay pretty nearby, since the onions need stirring every 10 minutes or so.
This page presents excellent step by step directions for caramelizing onions.
I generally use 2-3 Tbsp. olive oil for 3 large onions.
A neat trick to speed up the process is to add a pinch of baking soda to the pan just before you add the onions. (Really ***JUST*** a pinch ... I once added about 1/8 tsp. and instead of fragrant, sweet onions, I ended up with bitter, baking soda tasting onions!!)
Baking soda speeds up the process by raising the pH of the onion/olive oil mixture, which speeds up the chemical process of browning the onions and having them release their sweetness. See .... chemistry really DOES come in to play in every day matters!!
A great sounding idea about making carmelized onions in your SLOW COOKER has been posted by Bryanna Clark Grogan. Scroll down past the section on veggie broths. Using the slow cooker eliminates all the need for the frequent stirring. Doing a large, large batch in the slow cooker overnight produces plenty of carmelized onions to use when needed (they freeze well). Do take note of her recommendation to put the slow cooker OUTSIDE while the onions are cooking!! Apparently the 8 hours of slow cooking produces quite an odoriferous onion smell!!