How to Make Pickled Red Onions

Pick a medium red onion - around six ounces, three inches across. That size gives you nice rings that fit a pint jar with room to spare. Slice off both ends and peel away the papery outer skin. If your onion is bigger, slice it in half so it sits in the jar later. Smaller onions pickle faster, so if you're in a rush, grab a couple of small ones instead.

Cut a small notch on one side so the onion sits flat on the board without rolling. Slice crosswise into eighth-inch rings. Thin slices pickle faster and stay tender. A mandoline makes the cuts even if you want a clean uniform look in the jar. For a milder, crisper bite, slice from root to stem instead - that direction breaks fewer cells and keeps the sulfur down.

Grab a small saucepan and add a half cup of white vinegar, a half cup of apple cider vinegar, a quarter cup of honey, and a half teaspoon of kosher salt. Equal parts of the two vinegars balance the white's sharp punch with apple cider's fruity mellow. Honey rounds out the sweet better than plain sugar. If you're using granulated sugar instead, bump it to a third of a cup.

Set the pan over medium-high heat and bring the mixture to a boil. Stir as it heats so the salt dissolves and the honey melts cleanly into the vinegar. Let it bubble for about two minutes. The whole kitchen will smell sharp - that's normal. The heat both melts the sweeteners and primes the brine to do its color-change magic the moment it hits the onions.

Pile the sliced rings into a heatproof bowl or a pint mason jar. Slowly pour the hot brine over the top, covering every slice. Watch what happens - the onions start turning pink the second the vinegar touches them. The acidic environment reacts with the anthocyanins in the red onion skin and shifts the color from deep purple to bright magenta. It's the most satisfying part of the whole recipe.

Use a spoon to press the rings down so every slice is submerged in the brine. Let the bowl sit at room temperature for about thirty minutes. Check it every ten minutes and press the onions back under - they want to float to the top as they wilt, and only the submerged slices pick up the full flavor. They're ready when the rings bend without snapping and the color is bright magenta from edge to edge.

Scoop the rings and brine into a clean pint mason jar, cap it, and pop it in the fridge. They're ready to eat right away but taste their best after an hour cold. They'll keep for two weeks. Pile them on tacos, layer them onto a burger, scatter them over avocado toast, toss them into a Greek salad, or set them out as a magenta-pink centerpiece on a charcuterie board. The leftover brine makes a great salad-dressing base too.