Until now, what you’ve mostly been served is either onions sautéed with sugar or grilled onions. Make this recipe and you’ll understand how wonderful real caramelized onions are.
The short answer
Real caramelized onions have no sugar in them. Thick-sliced onions, a little olive oil and salt cook on the smallest burner at the lowest heat for 5–6 hours; they give up their water and their own sugar caramelizes. From 1 kg of onions you end up with roughly 400–450 g: dark and soft, but still with some bite.
Where this recipe came from
In the first burger video on Burger Haritası, the scene where I put the onions on the patty was lost in the edit. The question I got most under that video was “how did you make those caramelized onions?” This recipe is the answer.
Recipe
Caramelized Onions
- Prep10 min
- Cook5–6 hr · lowest heat
Ingredients
- ½ tea glass (about 50 ml) olive oil
- ½ tsp salt
- 1 kg onions
Equipment
Cutting board, knife, wide heavy-bottomed pot with a lid
Method
- Slice the onions into thick half-moons, about 1 cm each.
- Put the olive oil, onions and salt in a deep, heavy-bottomed pot.
- Cook, lid on, on the smallest burner at the lowest heat for 5–6 hours.
- Every 30 minutes (every 15 if your pot is thin-bottomed), lift the lid and stir so they don’t catch.
- When the onions reach the color and texture in the video, turn off the heat and let them rest.
Notes
- Packed hot into a sterilized jar and sealed, they keep for about 3 months; in the fridge, about 6 months.
- For correct sterilization, storage and packing, see the Storage section below.
Why I slice them thick
The onions cook for 5–6 hours. Slice them thin and they melt away to almost nothing. Cut them into half-moons about 1 cm thick and they keep a little bite at the end, which is the texture I want on a burger or in a sandwich.
Which onion?
I used ordinary brown onions, not white or purple. White onions give you milder caramelized onions; purple ones give a sweeter result.
Why no sugar?
Onions have their own sugar. Cooked low for hours, they lose their water, the sugar concentrates and caramelizes, and that is where the color and depth come from. Onions sautéed with sugar never get there. For the chemistry of browning: What is the Maillard reaction?
Is there a quick way?
Turn up the heat and the onions brown fast, but that’s fried onion, not caramelized: the outside burns before the sugar inside has time to caramelize. Time is the only secret here; you put the pot on and forget about it.
Tips
- A heavy-bottomed pot is essential. In a thin-bottomed pot the onions may catch no matter what.
- The smallest burner, the lowest heat. I shot the video on an electric stove; on gas the rule is the same.
- Add the salt at the start; it helps the onions release their water.
- Lid on. Stir every 30 minutes, or every 15 if your pot is thin-bottomed.
How to use them
These onions were made for burgers: on the patty, under the melted cheese. Pair them with my smashed burger, burger patty and melting burger cheese. They also work in toasties and sandwiches and next to a cheese board. For something sharper, try quick pickled onions; for something jammy, onion marmalade.
Storage
My note: Packed hot into a sterilized jar and sealed, they keep for about 3 months; in the fridge, about 6 months.
Please note: With home preserving, correct sterilization, storage conditions and packing matter most. Sterilize the jar and lid properly, fill the jar while the onions are hot and seal it straight away, and keep it somewhere cool and dark. Before opening, make sure the lid is not bulging and there is no foam, mould or bad smell; if in any doubt, don’t eat it. Keeping oily, low-acid foods at room temperature carries a risk of botulism if it isn’t done right. If you’re not sure, keep them in a sealed container in the fridge and use within a few days, or freeze them in portions.
Keep reading and listening
- Onions on our podcast YBYK (in Turkish): episode 13, King Onion and Queen Garlic
- Burgers on YBYK (in Turkish): episode 9, Burger 101
- The Burger Handbook: 22 homemade burger recipes
- What is the Maillard reaction?
- Onion marmalade
