Wood-pressed oils are trending these days. This is evident from the products listed on Amazon and the number of such outlets opening across towns, driven by rising consumer demand. People prefer them over what they usually consume today—refined oils. In that comparison, they are absolutely right. However, the comparison becomes misleading when wood-pressed oils are measured against expeller-pressed, crude filtered oils.

Health consciousness is great, but it should be accompanied by accurate knowledge. Decisions should be based on science, not just popular trends. While expensive often signals quality, that isn’t always the case. The wood-pressed oil fad is one such exception.

Let’s be clear—we’re not arguing that wood-pressed oil is worse than refined oil. On the contrary, wood-pressed oil is far superior to refined oil. But is it the best method for extracting oil? The answer is NO. Let’s examine why.

Two types of machines used to extract crude oil from copra:

• Expeller: A fully enclosed system where all moisture must be removed from the copra.
• Rotary: An open conical grinding machine where moisture must be present in the copra for lubrication.

Debate – Which is better?

Arguments in favour of the expeller:

• Moisture accelerates rancidity in oil. Removing it gives expeller oil a longer shelf life.
• Expellers extract more oil from the copra compared to rotary machines, increasing efficiency and reducing waste in the oil cake.
• Expeller machines can be scaled up by increasing size and power, enabling automation and large-scale processing.
• Oil from dried copra using an expeller can be filtered immediately using a filter press. In contrast, rotary-extracted oil from moist copra can only be filtered by sedimentation, which takes 7–10 days. So, expellers allow faster processing and require less inventory.
• The slight heating during expeller extraction enhances the aroma and taste of the oil.

Argument in favour of rotary (only one):

• Copra is not heated, so the natural properties of the coconut are retained.

But what properties are retained? The common answer is "vitamins." However, any coconut oil contains 99.9% fat and only 0.1% moisture. There are no carbohydrates, proteins, minerals—or even significant vitamins. It’s purely fat.

The heat involved in expeller extraction may reach up to 80°C and about 60°C in rotary extraction. Fats remain stable at these temperatures. If heating food is inherently bad, then why do we cook rice, roast chapatis, or pasteurise milk? Should we consume them raw?

From rotary, the trend moves further to wooden rotary instead of steel rotary.

• Oil yield is even lower, leading to higher labour and production costs, and hence, a more expensive product.
• Lower heat generation provides no added value in terms of taste or shelf life.
• Wood absorbs oil and moisture, which is unhygienic and unsafe for food production.
• Unused wood presses can develop bacteria and fungi on their surfaces.

In conclusion, rotary-pressed oil is inferior to expeller-pressed oil. Wood-pressed oil is even less efficient and more expensive, without offering meaningful advantages.

Moreover, roasting copra before extraction in an expeller further enhances the oil’s quality—improving flavour, aroma, and shelf life.