Pickling is the preservation of food in acid (vinegar) or through lacto-fermentation (salt brine). Quick-pickling (refrigerator pickles) uses heated vinegar brine poured over vegetables for a ready-in-hours result. Full fermentation pickles (like traditional kosher dills or Korean-style) develop complex sour flavours over days to weeks through bacterial conversion. Almost every cuisine has a pickling tradition — Japanese tsukemono, Korean jangajji, Indian achar, British piccalilli, Mexican curtido, Vietnamese đồ chua — and each uses distinct spice profiles and acid levels.
Quick pickle brine: 1:1 ratio vinegar to water, plus sugar and salt. Heat to dissolve, pour hot over sliced vegetables in a jar, cool, refrigerate. Ready in 1-4 hours, keeps 2-3 weeks. For fermented pickles: 3-5% salt brine (30-50g salt per litre of water), vegetables submerged with weight to keep below brine surface, fermented at room temperature 3-7 days. For Indian achar: mustard oil, fenugreek, mustard seeds, chilli — the oil preservation method is distinct from vinegar pickling. For Japanese tsukemono: salt, rice bran (nukazuke), or miso pressing — gentle, subtle preservation.
Quick-pickled red onion is the most versatile condiment you can make: thin-sliced red onion in hot brine of red wine vinegar, sugar, salt, and a bay leaf. Ready in 30 minutes, transforms tacos, salads, sandwiches, and grain bowls. For lacto-fermented pickles: add grape leaves or oak leaves to the brine — the tannins keep pickles crisp. The best bread-and-butter pickles use rice vinegar for a gentler, rounder acidity than white vinegar.
Using the wrong vinegar strength — pickling vinegar should be at least 5% acidity. Not keeping fermented pickles submerged — exposure to air causes mould. Under-salting fermented pickles — too little salt allows bad bacteria. Over-packing jars — brine needs to circulate. Using reactive metal lids — acid corrodes them. Treating all pickles as interchangeable — a Korean-style pickle is fundamentally different from a British pickle.