Caramelized Onion Jam Recipe: Sweet, Savory, and Simple

This caramelized onion jam recipe uses slow-cooked onions, brown sugar, and vinegar to create a sweet and savory spread that pairs beautifully with cheeses, sandwiches, and grilled meats. It’s a simple onion jam recipe built on technique, not shortcuts. The texture is soft and glossy, the flavor is balanced with just enough tang, and the result stores well for weeks. Whether you’re after a sweet onion jam recipe, classic onion chutney, or interested in onion jam recipe canning, this one delivers clarity and flavor.

The key to this recipe lies in the time it takes. Low heat and patience let the natural sugars in the onions break down and caramelize fully without burning. The sugar and vinegar support that process without overpowering it. Using 2 pounds of thinly sliced yellow onions gives the right bulk for even cooking. You get soft strands, not mush. A ratio of ¼ cup brown sugar and ¼ cup balsamic vinegar brings balance. It’s not sharp or overly sweet. It just works.

Long cooking, low heat, frequent stirring. Those are the three pillars. You don’t need fancy tools. A wide pan gives better surface area and control over browning. The texture builds gradually. first tender, then jammy. Nothing rushed, nothing raw.

For a brighter twist, see how I balance fruit with acidity in this Cherry Jam Recipe. It shares a similar principle of slow reduction.

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Ingredient Choices and What They Do

Yellow onions give depth and natural sweetness that red or white onions don’t quite match. I always slice them into thin half-moons about ⅛ inch thick. That way, they cook down evenly and hold their shape just enough.

Olive oil supports the slow sauté. I use two tablespoons. Too much makes it greasy, too little risks sticking. Brown sugar helps deepen the color and intensifies the sweetness without tipping it into syrup territory.

The balsamic vinegar adds body. Apple cider vinegar lightens it a little. I’ve tried it with just one or the other, but this mix gives the right push and pull. A bit of salt and black pepper grounds the sweetness. Fresh thyme is optional but worth adding for a more layered flavor.

If you love jams with richness and clarity, try the Fig Preserves Recipe. The use of sugar and acidity in both recipes follows a shared logic.

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The Caramelization Technique Explained

Getting the onions just right matters more than any spice or sugar. The slices should soften and collapse without browning too fast. That takes 30 to 40 minutes on medium-low. Stir often. If you walk away too long, they’ll catch.

Once you see golden color with a little stickiness at the edges, stir in the sugar and vinegar. The pan will sizzle slightly as the acid deglazes the base. That’s what you want. It lifts all the sweet bits and blends them into the mix.

The final simmer takes another 15 to 20 minutes. Stir often. You’ll know it’s ready when it thickens but still moves slowly on the spoon. Think soft strands suspended in syrup. It should not be dry or pasty.

If you prefer a fruit-forward spread, check out the Blackberry Jam Recipe. It handles thickness and shine in a similar way.

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How to Store and Keep it Fresh

This jam keeps in the fridge for two weeks, sealed tight. Use clean jars and always spoon out with a clean utensil. You can also freeze it in small containers for up to three months. It thaws quickly in the fridge overnight or in a bowl of cool water.

Canning is possible too. Just follow safe canning methods, using sterilized jars and water bath processing. That extends the shelf life without freezing.

Curious about canning with citrus? See my Homemade Orange Jam Recipe for more citrus-based preserves that follow similar storage logic.

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Practical Tips from My Kitchen

Use a wide, heavy-bottomed pan. It distributes heat better and gives more surface area for water to evaporate. I prefer cast iron or stainless steel over nonstick here.

Always slice the onions evenly. A mandoline helps if you’re making a large batch. Stir more often than you think you need to, especially in the last 20 minutes. That’s where most mistakes happen.

Let the jam cool before jarring. If it’s still steaming, condensation will water it down in the jar. Don’t skip the salt. It’s what makes everything else pop.

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Serving Ideas for Onion Jam

Spread it on toasted sourdough with goat cheese. Add it to burgers or sliders for extra depth.

Spoon it over brie or camembert and bake until melty. Mix into grilled cheese sandwiches with sharp cheddar.

Stir a bit into vinaigrettes for earthy contrast. Use it with grilled sausages or pork chops.

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Save This Recipe and Share Your Thoughts

Pin this onion jam recipe to your spreads or condiment boards so you don’t lose it.

Let me know in the comments how yours turned out. Tried it with red onions? Swapped vinegars? I’d love to hear what you made and how you used it.

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