Adding a pinch of bicarbonate of soda to onions cuts caramelisation time from an hour to 20 minutes, according to journalist Katherine McPhillips.
Caramelised onions add richness and sweetness to almost any dish, but achieving that result usually demands a fair amount of time at the stove. Cooking onions until they are perfectly caramelised can take well over an hour, and while the result is undeniably worth it, few people fancy spending that long over the hob each night just to prepare one ingredient.
The science behind the speed-up
McPhillips, who writes for the Express, said: "I'm fond of incorporating caramelised onions into my soups, stews or even serving them with pasta, so I set out to experiment and discover whether there might be a simpler approach."
"Following numerous attempts, I've found a method to achieve that sticky, golden result in half the usual time - requiring nothing more than a small amount of bicarbonate of soda."
Bicarbonate of soda might seem like an odd choice, but when introduced to onions, it triggers a chemical reaction that significantly speeds up the cooking process. Ordinarily, onions take so long to cook because their natural sugars need an extended period to concentrate enough for caramelisation to take place.
How to make quick caramelised onions
Bicarbonate of soda is alkaline, meaning even the tiniest amount will raise the pH level of the onions as they cook, allowing the sugars to break down far more quickly. Adding it to the onions leaves them soft, glossy and golden in just 20 minutes rather than an hour, all while preserving their rich flavour.
The method uses two large onions, one tablespoon of butter or olive oil, half a teaspoon of salt, one-eighth teaspoon of baking soda (a pinch), and optional white wine or balsamic vinegar.
Begin by placing the butter or oil in a frying pan over a medium heat on the hob. Finely slice the onions and add them to the pan once it has warmed up. Season the onions with salt and cook for five minutes until they start to look softened and turn yellow, stirring occasionally to stop them from sticking to the bottom of the pan.
Once the time is up, sprinkle the bicarbonate of soda over the onions and stir well. Turn the heat down to medium-low and continue cooking the onions for a further 10 to 15 minutes, until they turn golden-brown and take on a jammy texture. Once fully caramelised, a splash of white wine or balsamic vinegar can be added to deglaze the pan and elevate the flavour.
Your caramelised onions should look absolutely perfect in just 20 minutes, providing a delicious addition to your evening meal without keeping you tied to the kitchen all night.
