Wood-pressed, cold-pressed and refined oil: what actually differs
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Short answer: wood-pressed oil is crushed by a slow-turning wooden pestle, so it never heats up. Cold-pressed usually means a steel expeller run at a controlled temperature — unrefined, but faster and warmer. Refined oil is extracted with heat and a solvent, then bleached and deodorised. All three are legal edible oils. They are not the same product, and the difference shows up in smell, colour, shelf life and price.
What a wooden ghani actually is
A ghani is a mortar and pestle scaled up to furniture size. The mortar holds the seed; the wooden pestle turns inside it, slowly, crushing rather than grinding. In a traditional setup the whole cycle for one batch takes the better part of an hour.
The speed is the point. Friction makes heat, and heat is what damages the aromatic compounds and the fats you were trying to keep. Turn slowly enough and the oil comes out close to room temperature. This is why the regional names — lakdi ghani in the north, marachekku and chekku in Tamil Nadu, kolhu, ganuga — all describe the machine rather than the oil. The machine is the claim.
What "cold-pressed" means in practice
Cold-pressed is a looser term. In India it most often means a screw-type steel expeller run below a stated temperature. The oil is still unrefined and still carries the character of the seed. It is quicker, yields more, and costs less to produce than a ghani.
It is not a lesser product — it is a different trade-off. Worth knowing, though, is that "cold-pressed" is not a certified term the way "organic" is. The temperature is whatever the producer says it is.
What refining removes
Refined oil is the default on most shelves. Seed goes in, is heated, and is washed with a solvent — usually hexane — to pull out the last of the oil. What comes back is then degummed, neutralised, bleached and deodorised.
The result is an oil with no colour, no smell and a two-year shelf life. That is genuinely useful for industrial cooking and for anyone who does not want their food tasting of mustard. It is also, by design, an oil with the seed taken out of it.
Side by side
| Wood-pressed (ghani) | Cold-pressed (expeller) | Refined | |
|---|---|---|---|
| How it is extracted | Wooden pestle, low speed | Steel screw press, temperature-controlled | Heat plus solvent |
| Heat reached | Close to room temperature | Warm | High |
| Solvent used | None | None | Usually hexane |
| Bleached or deodorised | No | No | Yes |
| Smell and colour | Strong, seed-coloured | Present, milder | Neutral, pale |
| Cloudiness and sediment | Normal | Some | None |
| Typical shelf life | About six months | Six to nine months | Up to two years |
| Yield from the same seed | Lowest | Middle | Highest |
| Price per litre | Highest | Middle | Lowest |
How to tell which one you are holding
Open it and smell it. Groundnut oil should smell of groundnuts, mustard should catch in your throat, sesame should be nutty. An oil that smells of nothing has been deodorised, whatever the front label says.
Then look at it in daylight. Unrefined oil is the colour of the seed and often slightly hazy. Some will throw a sediment after a few weeks; coconut oil will set solid below about 24°C. None of that is spoilage.
Finally, check the shelf life printed on the bottle. An unrefined oil claiming two years has almost certainly been refined somewhere in the process.
Which should you buy?
If you cook at high heat in volume and want a neutral taste, refined does that job cheaply and there is no shame in it. If you want the oil to taste of what it came from, and you will finish the bottle inside a few months, unrefined is the reason to spend more. Between ghani and expeller, the honest answer is that the ghani is slower, yields less and costs more — and whether that is worth it to you depends on whether you can taste the difference. Buy a small bottle first and find out.
Written by the team at Purealth, who press on a wooden ghani in Ghansoli, Navi Mumbai. FSSAI Central Licence 11524998001133. Published 17 September 2026.