Walk into any grocery store and you'll find dozens of mustard oil bottles — refined, double-refined, filtered, kachi ghani. Most people pick based on price or brand. But the method of extraction changes the oil so fundamentally that you're essentially buying a different product.
Here's what you need to know.
What is Kachi Ghani?
Kachi Ghani literally means "raw crusher" or "cold press" in Hindi. It refers to the traditional wooden oil press (called a kolhu or chekku) where mustard seeds are ground slowly at room temperature without applying external heat.
The key characteristics of genuine kachi ghani mustard oil:
- Pressed at low RPM, which generates minimal heat
- No chemical solvents involved in extraction
- No bleaching, deodorising, or high-heat refining
- Natural colour, pungency, and nutrients are preserved
What Happens During Refining?
Refined mustard oil goes through multiple industrial processes:
- Solvent extraction — Chemical solvents (often hexane) are used to extract every last drop of oil from the seeds after initial pressing
- Degumming — Removes phospholipids and other naturally occurring compounds
- Bleaching — Removes colour using activated clay or chemicals
- Deodorising — High-heat steam treatment (200°C+) removes the natural smell
By the end of this process, the oil is lighter in colour, neutral in smell — and has lost much of what made mustard oil interesting in the first place: its natural glucosinolates, antioxidants, and distinct pungency.
Yellow vs Black Mustard Oil
Both yellow (peeli sarson) and black (kali sarson) mustard seeds can be cold pressed. The difference:
- Yellow Mustard Oil (Peeli Sarson) — Milder pungency, golden colour, more versatile. Good for everyday cooking, sautéing, pickles, and salad dressings. The oil has a slightly sweet, gentle heat.
- Black Mustard Oil (Kali Sarson) — More pungent, darker colour, stronger smell. This is the classic tadka oil of UP, Bihar, and Bengal. Higher in allyl isothiocyanate, which gives it that characteristic sharp bite.
How to Tell if Your Mustard Oil is Actually Cold Pressed
- Real kachi ghani oil has a strong, sharp pungency — not just mild spice. If your mustard oil doesn't make your eyes water a little when you open it, it's probably refined or blended.
- It should be a deep golden or amber colour, not pale yellow
- Genuine cold-pressed mustard oil may have very fine natural sediment at the bottom
Our Mustard Oils
At Chahal Agri Farms, we cold press both yellow and black mustard seeds in a traditional wooden kolhu at our farm in Singhpur Sani Village, Sambhal, West UP. No chemical solvents. No heat refining. No bleaching. The oil settles naturally and is gently filtered before bottling.