Take it cold - or how to press high-quality vegetable oil

Cold-pressed oil - probably every one of us has heard this term. But have you ever wondered what it means in practice and how this cold-pressed oil, praised by many, differs from hot-pressed oil?

It's high time to find out what is actually behind this advertising slogan.

To do so, however, it is worth briefly tracing the entire process of obtaining oil.

How is the oil made?

The production of oil, in this case vegetable oil, begins with the cultivation of plants suitable for this purpose.

In our climate zone, this is primarily rapeseed, sunflower, flax, poppy or the slightly less popular evening primrose.

These plants produce fats, as they are one of the main components that provide them with energy and support various life processes. Fats are mainly found in seeds, fruits and other parts, such as roots or stems. They are stored in plant cells in the form of oils or waxes.

The next step in the production of vegetable oils is harvesting.

The harvested oilseeds must first be cleaned and crushed.

Once this is done the next stage of oil production is possible, viz.

Oil pressing

This is the stage of production when the fats stored inside are extracted from the seeds.

The process of oil pressing is possible thanks to so-called oil presses.

Several types of such equipment are available on the market:

Oil pressing machines

Screw presses - most commonly used in industry, press oil with the help ofa

rotating screw, ideal for hot and cold pressing.

Hydraulic presses - use hydraulic force to squeeze oil, ideal for cold-pressed oil production, have higher oil quality.

Disc presses - use rotating disks to squeeze oil, used in medium production.

Solvent extraction presses - use chemical solvents, allow high output, but reduce oil quality.

What is the difference between cold pressing and hot pressing?

The answer to this question seems fairly obvious.

The key difference is, as is not hard to guess... temperature.

Counterintuitively, however, even in cold pressing, the seeds are heated to about 45°C. Raising their temperature to this level makes it easier to extract the desired fats from them while retaining most of their valuable nutrients, such as unsaturated fatty acids (omega-3, omega-6), vitamins (such as vitamin E) and antioxidants.

As a result, the oil retains its full nutritional value and has health benefits, supporting the cardiovascular system, immune system and skin.

Heat pressing is carried out at temperatures exceeding 100°C.

When heated, the seeds become softer, making it easier to mechanically squeeze the oil out of them.

Plant seeds also contain a certain amount of water, which evaporates as a result of heating, reducing the moisture content of the seeds.

Water can hinder the pressing process and reduce its efficiency.

Unfortunately, raising the pressing temperature leads to a loss of many nutrients and a reduction in oil quality. The process can also produce unfavorable compounds, such as oxidized fatty acids, which are harmful to health.

Heat-pressed oil often has a less pronounced taste and smell, which is also a result of the high temperature.

The heat-pressing process disappears some of the healthful components, such as polyphenols, that give the oil its distinctive flavor and aroma.

For those looking for oils full of nutritional value and flavor, heat-pressing is less beneficial.

Cold-pressed oils - healthier and tastier

So it's easy to conclude that cold-pressed oils are more valuable. They retain not only full flavor, but also nutrients - such as brain-saving omega acids and vitamins. Not surprisingly, such oils are more expensive, and their producers can make more money using the same raw material.

Filtration

The final step in oil production is filtration.

Filtration ensures that the oil is clean, clear and safe for consumption or further processing. Some oils, especially cold-pressed, may remain cloudy or contain particles of plant debris. In this case, depending on the manufacturer's preference, the oil may be further clarified to produce a transparent, aesthetically pleasing product.

Plate filters and frame and plate filters, among others, are used for effective filtration. However, the easiest way is to simply choose a ready-made oil pressing and filtration kit - you can find it here. This allows one device to produce filtered oil, ready for consumption or distribution.

Summary - cold-pressed oil vs. heat-pressed oil

Although heat-pressed oils may be cheaper and easier to obtain, their quality in terms of nutritional and health values is inferior to cold-pressed oils.

Cold-pressing preserves most of the oil's natural properties, including valuable vitamins, antioxidants and fatty acids, so such oils are considered healthier.

Of course, heat-pressed oils also have their uses, but if they are not stored properly, they can contain more harmful compounds, such as trans fatty acids and free radicals, so it is worth paying attention to their source and method of production.