Wood Pressed oils are a craze now. This can be seen in the products sold on Amazon and the number of such outlets opened in towns because of the massive consumer preference. I don’t say they are wrong because they compare it with what they consume today, i.e., refined oil. However, they are wrong when they compare wood-pressed oil with corresponding expeller-pressed crude, filtered oil. Health consciousness should rise, but they should also know what is healthy. Not go with what is popularly happening but scientifically reason it. Usually, what is priced higher is good, but not always. This fad about wood-pressed oil is one such exceptional case.

We don’t debate that wood-pressed oil is inferior to refined oil. Wood-pressed oil is far superior to refined oil, period. But is it the best way to make oil? The answer is NO! Let us analyse this.

Two types of machines to extract crude oil from copra

• Expeller is a fully closed arrangement; moisture should be removed entirely from the copra.
• Rotary is an open conical grinding machine; moisture must be present in the copra for lubrication.

Debate – which is better?

For expeller

• Moisture causes oil to go rancid. A better extraction mechanism should remove moisture so that expeller oil has a longer shelf life.
• The expeller squeezes more oil from the copra than the rotary. So, extraction efficiency is better, oil costs will be lower, and oil cake will have lower oil content wasted.
• By increasing the size and supplying more power, an expeller can crush a greater quantity of copra. This allows automation of the entire process on a larger scale.
• Oil extracted through an expeller from dried copra can be filtered online through a filter press. Oil extracted from rotary from moist copra can only be filtered by sedimentation, which will take 7-10 days. So, an expeller gives faster throughput and requires less inventory.
• The oil smells and tastes better because copra is heated to some extent.

For rotary – only argument

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

What properties of coconut would have been lost by heating? The common answer is vitamins. Any coconut oil contains 99.9% fat and 0.1% moisture. That means there is no other nutrient in coconut oil. Forget Vitamins; coconut oil has no carbohydrates, proteins, or minerals. It is only fat.
Heating may go up to 80 degrees in the expeller and 60 degrees in the rotary. At both these temperatures, the fats don’t undergo any change. If heating food is bad, then why do we cook rice, roast chapatis, and pasteurise milk? Shouldn’t we consume them raw?

From the rotary, it goes further down to the wooden rotary instead of the steel rotary.

• The extent to which oil is squeezed from copra is even lower. So, oil yield is lower, labour cost is higher, and hence, oil cost is much higher.
• The heat generated is even lower. So, there is no value addition of heat.
• Wood absorbs moisture and oil and retains it. This isn’t good for food hygiene and safety.
• When the wood press is unused, bacteria and fungus develop on the surface.

So, we have argued that rotary oil is inferior to expeller oil, and wood-pressed oil takes it a step further and is inferior and more expensive.
Now, in an expeller, roasting copra before oil extraction increases the quality to another level by enhancing flavour, taste, aroma, and shelf life.