Caramelized Onion and Apple Marmalade Recipe

This onion and apple marmalade is a small, easy recipe that transforms simple ingredients into a versatile condiment. Onions and apples are cooked gently until they are soft, sweet and glossy, with a hint of tang from apple cider vinegar. It’s quick to prepare, keeps well in the fridge, and pairs beautifully with pâté, pork pie, cheese sandwiches or sausages.

Why you’ll love this recipe

• Easy to make – the technique is simple: slice, soften and simmer. Most of the cooking time is hands-off while the marmalade caramelises.
• Economical – it uses inexpensive pantry staples: a few onions, a couple of tart apples, sugar, butter and vinegar.
• Long-lasting – stored in clean jars it keeps for weeks in the refrigerator or longer in the freezer when portioned.
• Highly versatile – use it with pâté, cold meats, roast pork or chicken, on burgers or stirred into stews and gravies for extra depth.

Recipe information

Prep time: about 10 minutes to peel and slice the onions and apples.

Cooking time: around 60–90 minutes total, including a low covered simmer then an uncovered reduction to thicken and caramelise.

Yield: 2–3 small jars, depending on jar size.

Ingredients for onion marmalade

(Exact quantities are listed in the recipe card below.)

• Onions – peeled and thinly sliced. White or brown onions work well; red onions give a different colour and flavour.
• Apples – tart varieties such as Granny Smith, peeled, cored and diced.
• Butter – for softening the onions.
• Sugar – granulated sugar to balance the acidity and help caramelise.
• Apple cider vinegar – adds brightness; a fruity vinegar works fine as an alternative.
• Dried thyme – or a small pinch of dried oregano or rosemary if preferred.
• Salt – to season.

Instructions

1. Melt the butter in a large saucepan over medium-low heat. Add the thinly sliced onions and stir to coat.
2. Add the diced apples, dried thyme and salt. Stir to combine.
3. Turn the heat down to low, cover the pan and let the mixture soften for about 15 minutes, stirring occasionally. The lid helps the fruit and onions release moisture and begin to break down.
4. Remove the lid and continue to cook over low heat for another 30 minutes, stirring often, until the onions are tender and lightly caramelised and the apple has mostly disintegrated.
5. Stir in the sugar and allow it to melt and blend with the fruit. Then add the apple cider vinegar.
6. Simmer uncovered for 30–40 minutes more, stirring occasionally, until the marmalade is thick, glossy and leaves a trail when you drag a spoon through it.
7. Adjust to taste: add more vinegar for sharpness or more sugar for sweetness.
8. Spoon the hot marmalade into clean sterilised jars, seal and allow to cool. Refrigerate for up to a month.

Tips for a successful outcome

• Cook slowly. Low heat and patience bring out the natural sweetness in the onions and apples.
• When you add sugar and vinegar the mixture will loosen; continue simmering until the excess moisture has evaporated and the marmalade becomes sticky and glossy.
• Use tart apples to balance sweetness and keep the final flavour bright.

How to sterilise jars

Properly sterilised jars will help the marmalade keep longer in the refrigerator. If you don’t sterilise jars, plan to use the marmalade within a week.

Oven method

• Wash jars and lids in hot, soapy water and rinse; leave them wet.
• Stand them upside down on a baking tray and place in a preheated oven at 180°C / 350°F for 15 minutes.

Microwave method

• Wash jars and rinse but do not dry. Microwave the wet glass jars for 2 minutes on full power.
• Do not microwave metal lids. Boil metal lids in a pot of water for 5 minutes instead.

Equipment

• Mandolin or a sharp knife for even onion slices.
• Vegetable peeler and apple corer (optional).
• Large saucepan with a lid for cooking.
• Two or three clean jars for storage.

Storage

Keep the marmalade in a sealed, sterilised jar in the refrigerator for up to a month. For longer storage, freeze portions in airtight containers for up to six months. Freezing in ice cube trays makes it easy to thaw small amounts as needed: thaw overnight in the fridge and bring to room temperature before serving.

FAQ

The recipe

If you try this recipe, I hope you enjoy the balance of sweet, savoury and tangy flavours. It’s an easy way to elevate simple meals and a great make-ahead condiment to have in your fridge.