What Is Mustard Oil?
Mustard oil is the pressed oil of mustard seeds — golden-yellow, intensely pungent, and deeply aromatic. It has been the dominant cooking oil of North India, Bengal, Nepal, and Pakistan for thousands of years, and remains one of the most flavourful and culturally significant oils in South Asian cooking.
Raw mustard oil has a sharp, almost harsh pungency — a nose-clearing intensity similar to wasabi or horseradish, caused by the same family of compounds (isothiocyanates). But when heated to smoking point — a technique used in traditional Indian cooking — this harshness transforms into a rich, nutty, deeply savoury flavour that no other oil can replicate. This transformation is central to understanding why mustard oil is irreplaceable in the cuisines that use it.
All mustard oil and Indian cooking ingredients are available at MasalaMart for UK delivery.
Why Is Mustard Oil So Important in Indian and Nepali Cooking?
1. Flavour That No Other Oil Provides
The primary reason mustard oil is used is its extraordinary flavour. Heated mustard oil has a complex, layered taste — pungent, nutty, slightly bitter, and deeply savoury — that becomes the flavour foundation of every dish cooked in it. Unlike neutral oils (sunflower, vegetable) that disappear into the background, mustard oil is a active flavour ingredient.
In Bengali cuisine, Nepali cooking, and Punjabi home kitchens, mustard oil is not merely the medium for cooking — it is part of the recipe. A Bengali fish curry cooked in mustard oil tastes fundamentally different from the same curry cooked in sunflower oil. Nepali achar made with mustard oil has a character that no other oil produces.
2. The Smoking Technique — Kaloncho
Traditional Indian and Nepali cooks do not simply heat mustard oil — they smoke it. The oil is heated in the pan until it reaches smoking point and begins to produce a light haze. At this moment, the sharp raw pungency of the oil breaks down and transforms into the characteristic rich, rounded mustard oil flavour that defines the cuisine.
This technique is called ‘kaloncho’ in Nepali cooking. Skipping it — using mustard oil at a lower temperature — leaves the raw, harsh quality in the dish. Smoking the oil first is what unlocks its full, proper flavour. It is a technique that takes seconds but makes a fundamental difference.
3. Indigenous to the Region
Mustard has been cultivated in the Indian subcontinent for at least 5,000 years. Unlike many cooking oils that arrived through trade or colonialism, mustard oil is indigenous — it grew here, it was pressed here, and it shaped the cuisine of the region before recorded culinary history. In North India, Bengal, and Nepal, mustard oil is not a choice — it is the default. It is what ‘cooking oil’ means.
4. Preservation Properties
Mustard oil has natural antimicrobial properties — its isothiocyanate compounds inhibit the growth of certain bacteria and fungi. This made it invaluable for food preservation long before refrigeration. Nepali achhars (pickles), Indian pickles (achar), and many fermented preparations traditionally use mustard oil as both flavour and preservative. Mango pickle, mixed vegetable pickle, and Nepali lapsi achar all depend on mustard oil for their keeping quality as well as their flavour.
5. High Smoke Point
Mustard oil has a smoke point of approximately 250°C — higher than many other cooking oils including extra virgin olive oil. This makes it ideal for high-heat Indian and Nepali cooking techniques: deep frying pakoras, searing meat for sekuwa, making tarka at very high heat. It is a genuinely versatile high-heat cooking oil.
6. Traditional Medicinal and Nutritional Properties
In Ayurvedic tradition, mustard oil is considered warming and stimulating — beneficial for circulation and digestion. It is used as a massage oil, a hair oil, and a medicinal oil across the subcontinent. Nutritionally, it has a favourable ratio of omega-3 to omega-6 fatty acids compared to many common cooking oils, and contains significant amounts of monounsaturated fats.
Which Indian and Nepali Dishes Use Mustard Oil?
- Nepali Momo filling: Mustard oil is the authentic fat in Nepali momo filling — it gives the filling its characteristic flavour that differentiates Nepali momo from Chinese or Tibetan dumplings
- Nepali Achar (pickles): Every Nepali achar — tomato, sesame, lapsi, gundruk — uses mustard oil as a base
- Bengali fish curry: The defining cooking oil of Bengali cuisine; mustard oil and fish are inseparable
- Punjabi sarson da saag: The classic Punjabi mustard greens dish is cooked in and finished with mustard oil
- Indian pickles (achar): Mango pickle, mixed pickle, chilli pickle — all use mustard oil
- Chaat and street food: Raw mustard oil is drizzled over chaat, kachumber salad, and street snacks in North India
- Tarka: Used for the final tempering in many North Indian and Nepali dals
Mustard Oil in the UK — A Note
In the UK and EU, mustard oil sold for culinary use is labelled “for external use only” due to its erucic acid content — a regulation that does not reflect how it is actually used by South Asian communities. Millions of people across the UK use mustard oil for cooking daily without issue, exactly as their families have done for generations. The regulatory label is a legal requirement, not a health warning based on typical culinary use.
Where to Buy Mustard Oil in the UK
Authentic mustard oil from trusted Indian brands is available at MasalaMart — delivered across the UK with free delivery on orders over £50.