North Indian achaar (pickle) — made from mango, lime, chilli, or mixed vegetables — is preserved through the combined action of salt, oil, and acid. Unlike Burmese lacto-fermented pickles or Japanese nukazuke, Indian achaar relies primarily on chemical preservation rather than active fermentation: the salt concentration (8–12%) suppresses bacterial growth; the oil coating excludes oxygen from the vegetable surfaces; the acid (from vinegar or the natural acidity of the fruit) further reduces pH to inhibit pathogens.
- **Mustard oil as the medium:** The traditional oil for achaar — its own antimicrobial compounds (allyl isothiocyanate) add preservative capacity beyond pure physical oxygen exclusion. - **Spice blend:** Mustard seed (whole and ground), fenugreek seed, fennel seed, dried chilli — the kalonji (nigella seed) is specific to North Indian pickle spice. - **Sun-curing:** Traditional achaar is left in the sun for several days after assembly — the UV exposure has antimicrobial effects; the heat evaporates additional moisture and intensifies the flavours. - **The salt percentage:** Too little salt and pathogenic bacteria are not suppressed. Too much and the pickle is unpleasant. The range: 8–12% of the total weight.
Indian Cookery Course