The Reason It's Important To Stir Onions When Caramelizing Them
Perfect on top of classic bruschetta, pizza, and salads, caramelized onions add a sweetened flavor and a golden-brown hue to many delectable dishes. They are a product of both the caramelization process and the Maillard reaction (per Serious Eats), the latter of which, involves the reaction between a food's sugars and amino acids. The reaction helps to create those coveted browned colors, as well as pleasant tastes and smells, via the learning center Byju's.
So what happens during the caramelization process? Serious Eats states that this is when sucrose breaks down into fructose and glucose, both simpler in structure, but sweeter in taste. This is why caramelized onions taste naturally sweeter than their raw counterpart, and no added sugar is needed.
But when caramelizing onions, you might be tempted to throw some onions in a pan or pot, let sizzling oil work its magic, and walk away. Not so. Like risotto, onions need to be stirred often to prevent two major mishaps from occurring. Here's what they are.
No one likes burnt or unevenly cooked onions
Kitchn states that failing to stir your onions may result in either burning or uneven cooking. This is because the bottom side of the onions will brown (and possibly blacken) while the top side will remain white. When you stir them, all sides will become cooked through and transformed into those soft strands of golden-brown onions. Better Homes & Gardens also explains that too much heat will surely cause your onions to burn, so keep the stove at medium or medium-high. They also emphasize that an overload of onions in the pan will cause uneven cooking, as some onions will become caramelized. Others will stay undercooked from being stacked on top of each other (this also slows down the overall cooking time).
So next time you're caramelizing some onions, be sure to give them a good stir every once in a while. This doesn't have to be a constant process either, as every 5-10 minutes is sufficient, according to Kitchn. Your onions will thank you with a sweetened flavor, which in turn, makes dishes like a French onion soup stand out as dinner party centerpieces.