So many different thoughts can come to mind when this term is uttered, heard, or read: Thin, dark brown strings in a mess. Thick, light brown tubes, nestled in what looks like a snake’s nest. Small diced, almost burnt little squares in what almost looks like a marmalade. I’m probably missing one or two, but suffice it to say there seems to be no limit to the versatility of the onion, and nothing magnifies this like applying the technique of caramelization.
I feel that from the jump, it needs to be clear that making caramelized onions does not involve any added sugar. I know it doesn’t intuitively seem like it, but onions actually have a lot of naturally occuring sugars. And what happens in this process is these sugars are caramelizing, turning the normally crisp, sweet and acidic features of the onion into a soft and deeply sweet version of its former self.
To prepare your onions for caramelizing, you can cut them in one of three ways. You can 1) thin slice or julienne them, cutting from root to top, with the grain of the onion’s fibers, 2) thick (or thin) slice them into either rings or half-moons, across the grain of the fibers, or 3) dice them, any size from small to large — but small is usually the best when electing to go with a dice. Which one you utilize is based entirely on personal preference, but I would recommend avoiding thin or small cuts until you become comfortable with the technique, as they are more susceptible to burning if left unattended for too long.
For the sake of this instruction, I’ve sliced (almost) two extra large onions in thicker half-moons.
When caramelizing onions, you should use a pot or pan with a heavy, thick bottom, and relatively high sides. Do not use non-stick cookware for caramelized onions. It’s also important to note that the volume of onions will shrink during this process to less than a fifth of what you started with — so if you start with four quarts of sliced raw onion, you’ll likely end up with no more than a quart of caramelized onions.
While the size, cut and even type of onion all represent the legit and viable variations you can put on their caramelized state, there are really only two cooking techniques through which the end result should be achieved.
First is the classic, “correct” method. This involves cooking the onions in butter, over a very long period of time (think 2-3 hours) over low heat, with frequent stirring. This gradually releases the natural liquid within the onions, slowly caramelizing them until they are a deep, bourbon-colored brown. The stirring should be done with a wooden spoon, so as to scrape the fonde off the bottom of the pot/pan as necessary.
While this is the method outlined by Escoffier (making it pretty much culinary law), much like many of his other haute cuisine preparations, it takes a lot of time and attention. As such, it has in turn been tweaked and adapted to accommodate the more hurried demands of the modern kitchen/cook, in the form of the second method…
The second (and more expeditious) method involves cooking the onions over medium to medium-high heat, in a technique that shouldn’t take longer than 25-35 minutes (depending on the volume of onions being caramelized). This is the strongly preferred method, and the one I will be walking through here.
First, preheat a high-sided, heavy-bottom pot/pan over medium-high heat, and add a high heat cooking fat (canola/vegetable oil, grape-seed oil or clarified butter are all great choices). Once the pan is smoking hot, add the onions, which should elicit a fairly loud sizzle upon contact, and stir them vigorously (again, using a wooden spoon) until they are mostly all coated somewhat in the oil.
Then, let them sit. Don’t touch or stir them for at least 10 minutes. During this time, the liquids are being drawn out and cooked off, but much more rapidly than with the first method. If you so desire, you can add a bit of salt at this point, to aid the process of drawing out the moisture.
In the first few minutes, you’ll notice liquid pooling in the bottom of the pan. Your ears should also notice a relatively high-pitched gurgling of that liquid simmering. The goal is to cook that liquid off, and then allow the onions to caramelize — which can’t happen (or at least will take for ever) if they’re being constantly moved or agitated. When the sound transforms into a (slightly louder) rough, medium-pitched murmur, the onions are probably ready to be stirred — but first you gotta check:
Take your wooden spoon (or tongs) and gently move only enough onions from the center of the pot/pan to see the bottom. If the bottom isn’t a nice golden brown, then return the bit of onion you disturbed and wait a little longer. If it is, then take your wooden spoon and stir vigorously, being sure to scrape up any fonde that has stuck to the bottom of the pan. If you’ve let it go a bit too long, and this is proving difficult, feel free to add a splash of water to help you deglaze the bottom.
Once you’ve done this the first time, slightly lower the heat to medium, and continue to repeat this step, allowing the onions to sit undisturbed until the bottom caramelizes every time. Each time you repeat this step, the amount of time you’ll need to let them sit undisturbed will get shorter and shorter.
Once you find yourself stirring as frequently as once a minute (so as to avoid burning on the bottom), the onions should be a beautiful deep brown and they should have a wonderfully sweet aroma, at which point, they are done.
At the end, you can (if you choose) again, add a splash of water to ensure you get all the good bits of fonde deglazed from the pan, and mixed in with the mass of now complete caramelized onions. Finish by stirring in a bit of salt, and you’re done!
*Notice the difference in volume between the raw onions at the beginning and the finished product — in the same pot!
One thought on “Caramelized Onions”
Thanks, dear, for another informative “how to.” I especially like the shortened version. I DO NOT have the patience for carmelizing onions. If I ever have the time, I’ll see if I can find a friend’s recipe for gorgonzola and carmelized onion pie. Yummy. XXOO