Cold-brine is just another way of saying pickled. Packing the vegetables separately prevents the colors from bleeding.
- 2 tablespoons coriander seeds, crushed
- 1 tablespoon mustard seeds
- 2 cups distilled white vinegar
- 2 tablespoons kosher salt
- 2 teaspoons black peppercorns
- 1 jicama, peeled, cut into ½”-thick sticks
- 1 medium cucumber, seeded, cut into ½”-thick sticks
- 1 jalapeño, seeded if desired, thinly sliced
- ½ pound small multicolored carrots, tops trimmed, scrubbed, halved lengthwise if large
- 2 heatproof 24-ounce jars
Toast coriander and mustard seeds in a dry medium saucepan over medium heat until seeds begin to pop, about 3 minutes. Add vinegar, sugar, salt, peppercorns, bay leaves, and 1 cup water and bring to a simmer over medium-high heat, stirring to dissolve sugar. Let cool.
Pack jicama, cucumber, and half of jalapeño in a jar, then pack carrots, radishes, and remaining jalapeño in other jar. Pour in brine, dividing evenly between jars. Cover and chill at least 4 hours. Drain vegetables before serving.
DO AHEAD: Vegetables can be pickled 1 day ahead. Keep chilled.