Pickled Red Onions
Pickled red onions are a vibrant condiment made with red onions, wine vinegar, caster sugar, caraway and fennel seeds. The Thermomix TM7 slices the onions uniformly and gently heats the sweet-sour brine to the ideal temperature, delivering crisp, jewel-toned onions that elevate burgers, salads and cheese boards in minutes.
About this recipe
Pickled red onions with the Thermomix TM7 are the quickest way to add colour, crunch and tang to almost any meal. If you have been searching for an easy pickled onion recipe for your all-in-one kitchen machine, this one delivers crisp ruby-pink rings steeped in a warm brine of wine vinegar, caster sugar, caraway seeds and dried fennel seeds, finished with a pinch of sea salt. The TM7 makes the process remarkably simple: you weigh the sugar and vinegar straight into the mixing bowl, grind the whole spices to wake up their fragrance, and heat the brine gently while the machine stirs automatically, so nothing scorches or boils over. Unlike manual pickling on the hob, there is no watching, no stirring and no guesswork. These onions are a brilliant meal prep staple for busy weeknights: spoon them over burgers, tacos, goat cheese salads or grilled sausages, and store the rest in a jar for up to several weeks. A stunning homemade condiment that looks far more effortful than it is.
Preparation tips
- Slice the onions as evenly as possible so they pickle uniformly; uneven rings mean some stay sharp while others turn soft. A mandoline or the TM7 blade gives the consistent thinness needed for that classic crunchy texture.
- Pour the brine over the onions while still warm so the vinegar and sugar penetrate quickly, then let the jar cool completely before refrigerating. The flavour deepens noticeably after a day, so make them ahead for parties.
- Swap caraway and fennel seeds for mustard seeds, coriander or a few peppercorns to change the character entirely. A bay leaf or a strip of orange peel adds a lovely festive note for cheese boards at Christmas.
Recipe variations
- Alcohol-free and mild version: replace the wine vinegar with apple cider vinegar or a mix of cider and water for a softer, kid-friendly tang. Add a little extra caster sugar so children enjoy the onions on burgers and hot dogs.
- Festive winter variation: add a cinnamon stick, a few cloves and a strip of orange zest to the caraway and fennel brine. The spiced ruby onions look beautiful on a Christmas cheese board or alongside roasted meats.
Thermomix TM7 Benefits
- Weighing the caster sugar and wine vinegar directly in the mixing bowl ensures a perfectly balanced brine with no measuring cups to wash up. [Built-in Scale]
- The TM7 grinds the caraway and fennel seeds in seconds, releasing their warm aroma far more intensely than whole seeds alone. [Multi-Function]
- Heating the vinegar brine happens at a controlled temperature in the Thermomix, so the pickling liquid never boils over on the hob. [Precision Control]
- Slicing the red onions evenly in the TM7 gives uniform rings that pickle at the same rate, staying crisp instead of turning mushy. [Multi-Function]
- Stirring happens automatically while the brine warms, meaning the sugar and sea salt dissolve completely without you standing at the hob. [Hands-Free]
Ingredients
- red onions
- red wine vinegar
- caster sugar
- caraway seeds
- dried fennel seeds
- fine sea salt