01 -
Combine apple cider vinegar, light brown sugar, granulated sugar, salt, ground ginger, granulated garlic, ground coriander, turmeric, and allspice in a large saucepan. Bring to a boil over medium-high heat, stirring constantly until sugars dissolve and mixture thickens slightly, about 3 minutes.
02 -
Add sliced jalapeños to the syrup (they will not be fully submerged). Return mixture to a boil over medium-high heat. Cook, stirring often, until chiles appear glossy, are softened, slightly shrunken, and visibly deepened in colour, 5 to 6 minutes.
03 -
Remove pan from heat. Using a slotted spoon, transfer chiles to a sanitized 500-millilitre canning jar, tapping or pressing chiles gently to pack tightly.
04 -
Return remaining syrup to the saucepan and bring to a boil over high heat. Cook, stirring occasionally, until reduced and thickened to approximately 240 millilitres, about 8 minutes.
05 -
Pour the hot syrup over the packed chiles, leaving 6 millimetres headspace. Discard any excess syrup. Secure lid. Let cool at room temperature for 1 hour, then refrigerate for a minimum of 48 hours before serving. Store refrigerated for up to 2 months.