Try adding these caramelized onions with balsamic vinegar to your burgers, steaks or hot dogs for an instant kick of lovely flavours. The onions are slowly cooked on the stove top with a dash of balsamic vinegar, allowing the natural sugars in the onions to break down and create a sweet exterior while leaving the onions perfectly soft.
Choosing the right onion
Caramelized onions are typically made using yellow onions, although you could use red onions as well. If possible, choose a really ripe onion, as they have the highest amount of natural sugars, and will bring the best caramelization. This recipe is my favourite way to use up any onions that have been laying around for a while.
Sauteed onions vs caramelized onions
If someone ever tells you that they can make caramelized onions in 5 minutes, bring on your best betterwizzer face and tell them "actually, those are sauteed onions".
Sauteed onions are made by cooking onions in oil or butter on medium to high heat on the stovetop until they soften. Using high heat can often cause the onions to slightly char or burn as well. Sauteeing onions is a common first step to make recipes that include onions, as the process gives onions a pleasant, sweeter flavour.
Caramelized onions, on the other hand, takes more time. We cook the onions on a lower heat for up to an hour, and add liquid through the cooking process to deglaze the pan and make sure the onions don't dry out and burn. The slow cooking process allows the natural sugars from the onions really break down, and create a sticky layer surrounding the onions. The onions turn golden brown, soft and sticky, almost glazed, without adding any sugar or sweeteners.
How to caramelize onions
Slice the onions in thick slices. Add butter to a large pot or saucepan on low to medium heat. Allow the butter to melt, then add the onions.
To caramelize onions, we will have to slowly cook them for a long period of time on low heat. The cooking process will take about 45 minutes to 1 hour. Stir through the onions every 5 minutes. If the pan goes dry and the onions start sticking to the bottom, deglaze the pan by adding a splash of balsamic vinegar and scraping the bottom of the pan to loosen up any sticky bits.
Repeat this process and deglaze the pan as many times as needed until the onions looks golden dark, sticky and perfectly caramelized.
Why balsamic vinegar
Balsamic vinegar is amazing in cooking. In this recipe we only add a few splashes to the onions as they caramelize. As the onions cook, the vinegar-y tang will mostly disappear. What remains is a hint of the balsamic flavour, which really compliments the sweetness of the onions.
Other liquids to try
If balsamic vinegar is not your thing, or you don't have it available, you can also try making caramelized onions using these liquids to deglaze the pan:
- Dry white wine - A good alternative and my second favourite. The alcohol will burn off during cooking, but the good flavours from the wine will remain.
- Apple cider vinegar - This makes the caramelized onions taste lighter, and is perfect if you're serving the onions with an apple based dish or side dish.
- Vegetable stock - A simple version that also works well.
Here are some of my favourite dishes that taste even better when topped with caramelized onions.
- Spicy beef burger - A juicy beef burger is always 100% better when topped with caramelized onions.
- Perfect pan seared pork loin steaks - Pork and caramelized onions go hand in hand. Trust me, it's delicious!
- Sweet Crockpot BBQ meatballs - BBQ meatballs don't need any toppings, but it's totally worth adding these onions for the ultimate potluck meatballs.
- Caramelized onion pizza - Savoury pizza is a great way to use caramelized onions.
Storing and freezing
Can you freeze caramelized onions? Absolutely! Allow them to cool completely before placing the onions in an airtight container and freezing it for up to 3 months. Allow the caramelized onions to thaw completely before reheating them in the microwave or on the stovetop.
Can you make it the day before? Yes. Caramelized onions can be stored in the fridge for up to 5 days. Keep in mind that they taste way better when served warm, so I highly recommend reheating leftovers if you're able.
Caramelized onions with balsamic vinegar
- 1 tbsp butter (or olive oil)
- 5 onions
- 2 tbsp balsamic vinegar
- Melt the butter in a saute pan or pot on low to medium heat.
- Slice the onions, and add them to the saute pan. Stir to coat them in the butter, and leave them to cook until they soften.
- Stir through the onions every 5 minutes to make sure they don't stick to the bottom of the pan. When they start to stick, add some balsamic vinegar to deglaze the pan and prevent the onions from burning.
- Repeat as often as needed, adding splashes of vinegar to prevent the burning. The onions will have to cook for 45 min - 1 hour to fully caramelize.
Other liquids to tryIf balsamic vinegar is not your thing, or you don’t have it available, you can also try making caramelized onions using these liquids to deglaze the pan:
- Dry white wine – A good alternative and my second favourite. The alcohol will burn off during cooking, but the good flavours from the wine will remain.
- Apple cider vinegar – This makes the caramelized onions taste lighter, and is perfect if you’re serving the onions with an apple based dish or side dish.
- Vegetable stock – A simple version that also works well.