Pickled Red Onion
Pickled red onion turns a sharp, raw onion into soft, bright pink rings with a sweet-sour bite that lifts burgers, tacos, cheese sandwiches and salads. All it takes is a hot brine of vinegar, sugar and salt poured over thinly sliced onions. They are pleasantly tangy after an hour, keep in the fridge for up to three weeks and get pinker the longer they sit.
- Total
- 1 h 20 min
- Prep
- 15 min
- Cook
- 5 min
- Serves
- 1 x 500ml jar (about 350g)
- Per 2 tbsp (25g, drained)
- 14kcal
Sterilising the jar for pickled red onion
Because this is a fridge pickle, a jar that is very clean is enough for a couple of weeks. If you want the full three weeks, or you are giving a jar away, sterilise it in the oven as in the first step. Use a lid with a plastic lining or a glass seal, since bare metal reacts with vinegar and can taint the taste.
White wine vinegar gives a clean, mild pickle. Look for one with 5–6 per cent acidity, which most supermarket bottles are.
Pickled red onion method
Tap a time to start a timer.
- Clean the jar Wash the jar and lid in hot soapy water and rinse well. For the longest keeping, stand the jar upright on a baking tray in an oven at 140°C (120°C fan), gas 1, for to sterilise it, then let it cool a little while you slice.
- Slice the onions Peel the onions, halve them from root to tip and slice into half moons about 2–3mm thick. A mandoline makes this quick and even. Pack the slices into the jar.
- Heat the brine Put the vinegar, water, sugar, salt and peppercorns in a small saucepan over a medium heat. Stir for until the sugar and salt dissolve, then take it off the heat as soon as it comes to a simmer.
- Pour and submerge Pour the hot brine over the onions until they are completely covered. Press them down with a spoon. Leave the jar uncovered for about until it reaches room temperature, by which time the onions will have turned pink.
- Chill Put the lid on and refrigerate for at least more. They are ready to eat after an hour and best the next day. Keep them in the fridge, with the onions under the liquid.
What to serve with pickled red onion
Pile the onions on a burger or into chickpea burgers, add them to cheese sandwiches and ploughman's, or scatter them over tacos and rice bowls. They also cut through the richness of an omelette with cheese and give a fresh, sharp contrast to a bowl of couscous salad.
For variations, add a bay leaf, a few coriander seeds or a pinch of chilli flakes to the brine. A clove of sliced garlic works well too.
Common problems and fixes for Pickled Red Onion
- The onions have gone limp rather than crunchy.
- The slices were probably too thick or the brine was left to boil on the hob. Cut them 2–3mm thick, take the brine off the heat as soon as it simmers, and eat the jar within two weeks for the best crunch.
- The onions are not very pink.
- Colour comes from the acid, so any slices poking above the liquid stay pale. Press them under the brine, and give the jar a few hours. The colour deepens overnight.
- The brine is too sharp for your taste.
- Warm the brine gently, stir in 1 tsp more sugar until it dissolves, then pour it back over the onions. Next time, use 3 tbsp sugar in the first place.
Frequently asked questions about Pickled Red Onion
How long does pickled red onion keep in the fridge?
Up to three weeks in a sealed jar, with the onions kept under the brine. They are crunchiest in the first two weeks. Throw them away if the brine turns cloudy and smells off, or you see mould.
Can I use a different vinegar?
Yes. Apple cider vinegar gives a fruitier, slightly milder pickle, and red wine vinegar works too. Avoid malt vinegar, which is harsh and turns the onions brown rather than pink.
Do I have to keep them in the fridge?
Yes. This is a quick pickle with less vinegar and sugar than a shelf-stable one, so it needs to stay cold. Do not store the jar in a cupboard.
Can I reuse the brine?
You can use it once more. Bring it back to the boil, pour it over fresh sliced onions and expect a milder result. After that, throw it away.
How did you like the recipe?
4.7 / 5 · 32 ratings
