Cold wood pressing is the traditional method of extracting oil from seeds/fruits. The raw material (sesame/ peanut/ coconut/ sunflower seeds) is typically ground into a paste, and this is pressed with a heavy stone mill, turned by bullocks, until it expels the oil. This cold wood-pressed oil is sold unrefined, and without any additives.
“Cold-pressed oils have all their nutrients intact, retaining the natural properties of the oilseeds, unlike refined oil. It’s a bit like atta and maida, the source is the same, but atta far superior to maida. Refining degrades nutritional value, and more significantly, introduces harmful trans fats to improve shelf life for commercial reasons.
But, refined oils, produced on a large scale (the output for a commercial oil mill runs into tons, as opposed to a small chekku , whose daily output can be gathered in two tins!) and backed by vigorous media campaigns, had almost done away with traditionally extracted oils. Except, now, as with all things organic and natural, it’s increasingly becoming popular in urban homes.
There is a lot of awareness now, on cold-pressed oils. Oil yield from traditional Ghani / mara chekku method is less compared to modern Expeller / refined chemical extraction method. The low yield is because the oilseeds are not heated to increase the yield, and the oil that is extracted is cold and pure. Insisting on the importance of cold oils, the oil extracted by large-scale mechanical presses comes out warm.
“We Indians sadly only woke up to our age-old methods of oil extraction when the olive oil lobby began trumpeting terms such as ‘cold-pressed’ and ‘extra virgin. Besides, sesame oil is in no way inferior to olive oil. Both are mono-unsaturated oils, and cold-pressed sesame oil has similar health benefits. So, there’s no pressing need to substitute imported olive oil in our recipes and compromise on the taste of South Indian food. Cold-pressed sesame oil smells and tastes especially good. When commercially manufactured, molasses is added to the oil, to mask its natural bitterness; but in a chekku, we add palm sugar or jaggery, which heightens its flavour.” And oil from a chekku keeps for a year if it’s stored in clay utensils.
Understanding the importance of including more than one variety of cold-pressed oil in the diet, South Indian menus have always incorporated three — groundnut oil (with its high heating point) for frying, coconut oil for dressing, and sesame oil for curries and gravies. All the three have their own benefits. As much as coconut oil has received bad press being high in saturated fatty acids, which are considered potential artery cloggers, ironically it has medium chain fatty acids that are seen as heart protectors. However, to err on the side of caution, recommendation is using these different oils (in moderation) like they were traditionally used in different dishes to get the benefit of each oil, especially in combination with other ingredients. For example, in a Kerala fish curry, the combination of kokum, fenugreek, Kashmiri chilly and oily fish might just complement a spoon of cold-pressed coconut oil drizzled on top while serving. These areas are greatly under-researched,” she says.
But whichever oil you use, use it sparingly. One gram of oil has 9 calories; 1 teaspoon, therefore, has 45 calories, the equivalent of half a chapatti. Remember, the unburned calories will sit around as fat!
What are different types of Oil extraction methods? Which is the best method and why?