What Does Kachi Ghani Mean, and Is It Cold Pressed?

For mustard oil sold in India, kachi ghani and cold pressed are the same label. The food product standard permits either phrase under one shared condition: natural allyl isothiocyanate of not less than 0.20 percent by weight. Wood pressed appears nowhere in that standard, and neither does expeller pressed.

So two of these three words are testable in India and the third is not. The threshold tests the finished oil, not the temperature or the press.

What is a ghani, and what does "kachi" actually mean?

A ghani, also known as a kolhu or chekku, is a mortar and pestle. Oilseed sits in a pit at the centre of a round stone or wood mortar, and a heavy vertical pestle rotates inside it, first smashing the seed and then crushing the oil out.

Kachi describes the seed, not the machine: modern screw pressing heat conditions the seed first, in what the industry calls a stack precooker. A kachi ghani takes it uncooked.

However, the process is not cold. The FAO account by food scientist K.T. Achaya describes water added in two stages. The first lets the pestle grip, and the friction brings about heat. The second effectively cooks the ground seed, which Achaya calls directly analogous to a modern precooker. So a ghani is not a zero-heat operation; it is a low-pressure, low-capacity one.

Does "kachi ghani" have a legal definition in India?

Kachi ghani does have a legal definition in India, and it is narrower than most buyers assume. Under India's food product standards, mustard oil may be labelled as Kachi Ghani or Cold Pressed if the content of natural allyl isothiocyanate is not less than 0.20 percent by weight. That is the entire condition.

Notice what it does not say. It sets no maximum pressing temperature, names no press, and requires no kolhu of any kind. It measures one compound in the finished oil.

Allyl isothiocyanate is the compound that makes mustard oil sting, and it is absent from the intact seed. It forms when glucosinolates in crushed seed meet moisture and enzyme activity, and Achaya records that the Bengal ghani's long run exists precisely to allow that slow liberation. Heat and refining strip it out again, so the threshold is a proxy, not a guarantee about method.

Solvent-extracted or imported mustard oil must also be refined before sale, with hexane capped at 5.00 ppm.

How is cold pressing different from expeller pressing?

Cold pressing and expeller pressing are both mechanical, and the only difference between them is heat. An expeller is a screw press: a rotating screw forces seed through a slotted cage until the oil is squeezed out through the slots. That friction alone raises the temperature. Cold pressing is the same principle run slower, with no external heat applied.

A 2025 trial ran a screw press from 30 to 140 degrees Celsius, using hempseed rather than mustard, so read the direction, not the absolute figures. Yield peaked at 100°C, about four percent above pressing at 30°C, while peroxide value, an oxidation marker, more than doubled from 6.36 to 13.86 milliequivalents of oxygen per kilogram.

One result cuts against the usual marketing: the fatty acid profile did not change at any temperature tested. Heat moved the minor compounds and oxidation markers, not the fats.

What do solvent extraction and refining do to the oil?

Solvent extraction is not pressing at all. Flaked seed is washed with hexane, which dissolves the oil out of the solids. It is far more efficient than any press, and the crude oil cannot legally be eaten in India until refined.

The American Oil Chemists' Society says a modern screw press leaves about 7 to 8 percent residual oil in the solids, while hexane extraction removes all but about half a percent. That is largely why refined oil is cheap.

Refining then runs in four stages: degumming removes phospholipids and metal ions, neutralisation strips free fatty acids, bleaching removes pigments and oxidation products, and deodorisation is a vacuum steam distillation, conventionally at 190 to 240°C for two to three hours.

Those volatiles include the allyl isothiocyanate the Indian threshold measures, which is why refined mustard oil is pale, nearly odourless, and cannot honestly be called kachi ghani. Spotting the difference on a shelf is covered in our guide to refined mustard oil sold as pure.

Why does low-temperature pressing yield less and cost more?

Pressure and heat both make oil flow, and a low-temperature press uses less of both. The shortfall shows up in the residue: ghani cake carries about 15 percent residual fat, roughly twice that of screw-press cake.

Achaya puts the gap at about five percent less oil from an oil-rich seed in a ghani than in a modern expeller, and even a power ghani presses at best 100 kg of oilseed in a day.

What does "wood pressed" add over "cold pressed"?

In regulation, nothing, because wood pressed is not a defined term. In practice it means a kolhu whose mortar and pestle are hardwood rather than steel: a real and checkable manufacturing description, just not one any Indian authority polices.

The case for a wooden kolhu is mechanical, not magical. Wood conducts heat poorly compared with steel, and a kolhu turns slowly, so less frictional heat builds up. Tamarind, or imli, is among the hardwoods used for ghani mortars.

SatRas is a worked example, not a claim. Its oils are pressed in a wooden kolhu with an imli wood core, which the brand describes as roughly five times slower than conventional pressing, and are sold unrefined and unbleached, with no chemical solvents or deodorising agents.

Its yellow mustard oil is stated as extracted below 49°C, its black mustard oil is chosen for the pungency allyl isothiocyanate drives in tadka and pickling, and its high oleic oil comes from the Raya Hisar 1706 variety developed by CCSHAU.

How do the four extraction methods compare?

Method	What happens	Heat	Oil left behind	Defined in Indian regulation?	Sources
Ghani or kolhu (kachi ghani)	Pestle crushes uncooked seed in a stone or wood mortar	Frictional only, no precooking	About 15% in the cake	Yes, via the 0.20% allyl isothiocyanate threshold	Achaya, FAO, FSSAI standard
Cold pressed screw press	Screw press run slowly, no external heat	Friction only; a producer can state a figure	Roughly 7 to 8%	Yes, same clause and threshold	FSSAI standard, AOCS
Expeller pressed	Same press run faster, seed usually precooked	Raised by friction and precooking	Roughly 7 to 8%	No	AOCS, 2025 press trial
Solvent extracted and refined	Hexane dissolves the oil, then degumming, neutralisation, bleaching, deodorisation	Deodorisation at 190 to 240°C for two to three hours	About 0.5%	Refining mandatory before sale, hexane capped at 5.00 ppm	FSSAI standard, AOCS, Foods, 2022

Wood pressing is not a separate method. It is a ghani with a hardwood mortar and pestle, and sits inside the first row.

Which of these words should you actually trust?

"Kachi ghani" and "cold pressed" have value on a mustard oil bottle because one measurable threshold sits behind both. "Wood pressed" and "expeller pressed" have none, because nothing sits behind them. The checkable questions are what temperature and what press.

Ask for a temperature instead of an adjective, since a producer pressing cool can state a number. Ask what happened after pressing, given that bleaching and deodorisation are where the colour and volatiles go.

Ask which variety was used, because cultivar sets fat composition before pressing. That is why SatRas names a variety for its high oleic oil and publishes per-100g values across its range of mustard oils, with sourcing detail on the SatRas FAQ page.

One limit is worth stating. Low-temperature pressing limits nutrient degradation and oxidation, but it cannot create nutrients. Any bottle promising that a pressing method retains everything is claiming more than the evidence supports.

This article is educational and is not medical advice. For dietary guidance, speak to a qualified healthcare professional.

Frequently asked questions

What does kachi ghani mean?

Kachi means raw or uncooked, and ghani is the traditional mortar and pestle oil press, also called a kolhu or chekku. The phrase describes seed crushed without being heat conditioned first, unlike modern screw pressing, where seed passes through a precooker before reaching the press.

Is kachi ghani the same as cold pressed?

For mustard oil sold in India, yes. The food product standard allows the oil to be labelled either Kachi Ghani or Cold Pressed under one shared condition, natural allyl isothiocyanate of not less than 0.20 percent by weight. There is no separate test for one term against the other.

What is the difference between cold pressed and wood pressed oil?

Cold pressed describes the temperature condition of the pressing. Wood pressed describes the press itself, usually a kolhu with a hardwood mortar and pestle. Cold pressed carries a defined threshold for mustard oil in Indian regulation, while wood pressed carries none.

At what temperature is cold pressed oil extracted?

Indian regulation sets no maximum pressing temperature, so the honest answer depends on the producer rather than the label. Mechanical presses generate heat by friction even with no external heating, so ask the brand for a stated figure. Press trials show yield and oxidation rising together.

Why is cold pressed mustard oil more expensive?

Because it extracts less oil from the same seed and does it far more slowly. Traditional ghani cake retains about 15 percent residual fat, roughly twice that of screw press cake, and even a modern power ghani presses at best around 100 kg of oilseed in a working day.

Is refined mustard oil the same product as unrefined?

Refined mustard oil comes from the same seed but not the same process. Solvent extracted oil must be refined before sale for human consumption in India, through degumming, neutralisation, bleaching and deodorisation. Deodorisation runs at high temperature and removes the compounds that give unrefined mustard oil its colour and pungency.