Name: Caramelized Onion Jam
Prep time: 10 min
Cook time: 35 min
Total time: 120 min
Ingredients: 4 medium yellow onions (approx. 1½ lbs, medium dice); 2 tsp salt (plus additional to taste); 1 tsp olive oil; 1½ tsp ground black pepper; 2 tbsp fresh thyme leaves (divided); ¼ cup red wine vinegar; ⅓ cup balsamic vinegar; ¾ cup granulated sugar (plus 2 tbsp); 1 lemon (zested (1 tsp) and juiced (2 tbsp))

Caramelized Onion Jam with yellow onions, thyme, balsamic vinegar, red wine vinegar, lemon, and sugar.

The first time I tasted Caramelized Onion Jam, I was standing in someone else’s kitchen — you know that slightly awkward moment when you don’t know where anything is, but you pretend you do? We were at a low-key backyard get-together. Nothing fancy. Folding chairs, someone’s dog weaving between ankles, paper plates that sagged under too many snacks.

A friend plopped a spoonful of this glossy, dark onion jam onto my burger, insisting “Just try it — trust me.” And honestly? I didn’t trust them. I mean… onion jam sounded like a culinary prank. But I took a bite anyway — I was hungry — and oh my gosh. I remember this weird little pause in my brain, like when you hear a new song and just know it’ll be stuck with you for ages.

It was sweet, but not too sweet; tangy, but not sharp. Cozy, but still bright. It was like the onions took a semester abroad in Italy and came back wearing fancy scarves and telling stories. Something about it just hit me emotionally. I know that sounds dramatic for condiments, but food can be funny that way — it sneaks in little memories without asking permission.

Remember it later!

Planning to try this recipe soon? Pin it for a quick find later!

Remember it later!

Planning to try this recipe soon? Pin it for a quick find later!

Later that month, I tried making my own batch of Caramelized Onion Jam. My kitchen windows fogged up, thyme perfumed the whole house, and my counter looked like a tiny onion graveyard. I kept poking the pan, not totally sure if I was doing it right. It didn’t look like the jar we’d had at the barbecue. Too light at first. Then too dark. But then… somewhere in the middle of stirring and tasting and guessing, it happened.

That deep, delicious aroma — like a restaurant where the waitstaff wears black aprons and you always leave feeling slightly cooler than when you walked in. The jam tasted incredible, in that messy, homemade way that just feels honest. Even now, every time I make it, there’s a tiny moment where I think, “Is this going to turn out?” And the answer is usually yes, though every batch is a tiny bit different. I kinda love that.

Here’s a quick peek at what’s inside:

Why You’ll Love This Caramelized Onion Jam Recipe?

Caramelized Onion Jam is the kind of thing you don’t know you need until it shows up and suddenly everything tastes better. It’s like that one friend who makes every group hang way more fun, just by being there.

One of the coolest things is how simple ingredients — onions, vinegar, sugar, thyme — somehow transform into this glossy, spoonable magic. Not too sweet, not too sharp. Warm and cozy but also wakeful, if that makes sense. I love that you can spread this onion relish on a sandwich and instantly feel like you upgraded lunch from “meh” to “wow, am I on a cooking show?”

It’s also strangely versatile. Burgers. Roasted chicken. Steak. Hot dogs. Cheese boards. It’s like the caramelized flavor threads itself into everything without overpowering. The thyme adds this little herbal whisper — not a shout. The balsamic gives depth, like a good late-night conversation. And the lemon keeps things alive, bright, a little sparkly.

And maybe the best part? Every jar of Caramelized Onion Jam feels slightly unique. Softer one time, thicker the next, a little sweeter because you accidentally added too much sugar — imperfections that make it feel more human. And honestly, that’s kinda the fun.

Ingredient Notes:

There’s a sweet simplicity to this Caramelized Onion Jam. Nothing complicated, nothing you can’t find at a normal grocery store. It’s like the band where everyone plays backup and no one tries too hard.

Yellow onions – They’re the heart of it all. Sweeten up beautifully with time and heat. Sometimes I use slightly larger ones because I get carried away.
Salt – Helps soften the onions. Also, it sharpens the flavor in this sneaky little way.
Olive oil – Just enough to help everything move in the pan.
Black pepper – Adds warmth; tastes like a gentle nudge.
Thyme – Fresh thyme is dreamy — a tiny herbal invitation.
Red wine vinegar – Bright and sharp, but not rude.
Balsamic vinegar – Thick, deep, almost moody. Balances the sweetness.
Sugar – The sweetness and caramel work together like old friends.
Lemon zest + juice – Adds zing, keeps everything from feeling heavy.

It’s funny — you look at this ingredient list and think, “Really? That’s all?” Yes. And somehow it feels like alchemy.

How To Make Caramelized Onion Jam?

I like to think of making Caramelized Onion Jam as a gentle two-hour mini-retreat. It’s slow, but in a nice way — the kind of slow that gives you room to think (or not think at all). Put on music. Wear comfy socks.

Step 1 — Salt + Rest

Dice your onions. Mix with salt. Let them hang out for an hour. This step always makes me laugh because it feels like the onions are just… taking a break. The liquid that forms is important — don’t throw it out.

Step 2 — Sauté

Heat olive oil in a skillet. Add the onions and the liquid. Sauté until they turn soft and translucent, about 10 minutes. The kitchen will start smelling amazing — the kind of smell that makes your neighbors wish they’d been invited. Add pepper + half the thyme.

Step 3 — Vinegars Join the Party

Lower the heat and add the red wine + balsamic vinegars. They bubble, they steam, they reduce a little. Stir now and then. After 10 minutes or so, things thicken slightly. At this point, I usually lean in to smell it, like a weirdo.

Step 4 — Caramelize

Crank it up to medium-high. Add sugar, lemon juice, and zest. Now the real magic happens. Everything darkens — slowly — and becomes thicker and silky. Don’t rush it. Keep stirring sometimes so it doesn’t stick. When you can drag a spatula through and it leaves a path that slowly closes, you’re good.

Step 5 — Cool + Taste

Want To Save This Recipe?

Enter your email below and we'll send the recipe straight to your inbox.

Turn off the heat. Stir in the remaining thyme. Cool it right in the pan — no fancy tricks. Taste. Maybe add more salt. Or don’t. Follow your heart.

Step 6 — Store

Transfer to a jar. Refrigerate. It’ll thicken more. I always sneak a bite while transferring… which probably ruins the whole “clean jar” look, but whatever.

Storage Options:

Caramelized Onion Jam lasts beautifully in a jar in the fridge — about 1–2 weeks. If you’re a saver (or a batch-cooker), you can freeze it for up to three months. I’ve done it, and it works great, though sometimes I forget it’s in the freezer… and then I rediscover it like treasure.

Variations and Substitutions:

There’s no single “correct” Caramelized Onion Jam. I’ve played around a bit, depending on mood, ingredients, and what’s happening in life.

Try rosemary instead of thyme
Add chili flakes for a little drama
Splash in bourbon (just a tiny bit)
Replace sugar with brown sugar
Swap red wine vinegar with sherry vinegar
Add minced garlic early on

Sometimes version #1 is best. Sometimes version #5. That uncertainty is part of the charm.

What to Serve with Caramelized Onion Jam?

Honestly? Caramelized Onion Jam goes with almost anything. It’s like that friendly person who gets along with everyone at the party — a social condiment.

Burgers (trust me)
Steak
Roasted chicken
Sandwiches
Grilled cheese — oh wow
Charcuterie boards
Brie + crackers

Sometimes I even mix a spoonful into pasta or eggs when I’m feeling chaotic. It hits every time.

Frequently Asked Questions:

Do I have to salt the onions first?
It helps. Skipping it isn’t the end of the world — just cook longer.

Can I use red onions?
Totally. They’ll make a darker, sweeter Caramelized Onion Jam.

Is it sweet?
Yes. But also tangy, savory, bright. It’s layered — like people.

If you try this Caramelized Onion Jam, tell me what you paired it with. Or if you ate it directly out of the jar at 11 p.m. while standing in the kitchen with the fridge open — because same.

Remember it later!

Planning to try this recipe soon? Pin it for a quick find later!

Remember it later!

Planning to try this recipe soon? Pin it for a quick find later!

Keep the Flavor Coming – Try These:

Sausage Breakfast Casserole Recipe

Butterfinger Balls Recipe

Crock Pot Great Northern Beans