Oil pressing – a short guide
Vegetable oil is one of the basic food products, produced in various latitudes since antiquity. Its different varieties often determine the character of local culinary practices. After all, it is hard to imagine Mediterranean cuisine without the characteristic taste of olive oil, or Asian dishes without a few drops of sesame oil. In the areas of present-day Poland, inhabited by our Slavic ancestors, methods of obtaining oil from seeds were already known at the beginning of the first millennium of our era. However, until the 19th century, most oil production in our region was non-industrial in nature. This means that small communities or manors produced oil for their own use.
Currently, various types of oil are readily available in every store, but the practice of pressing your own oils still has many undeniable benefits. Especially today, when modern oil presses are compact, efficient and easier to operate than ever before.
What to press oil from? Not only rapeseed and sunflower…
Although the most popular varieties of vegetable oils in Poland are rapeseed oil and sunflower oil, the range of possibilities for an oil press owner is much wider. A popular alternative oil is, for example, flaxseed oil. It is one of the healthiest oils, rich in omega-3 fatty acids (alpha-linolenic acid). In Poland, flax is cultivated mainly in the east and south of the country, and flaxseed oil is widely used in the kitchen (mainly for salads and as a dietary supplement) as well as in cosmetics. Flax is also used in the textile and construction industries. Slightly less popular varieties also include soybean oil, which is used both in the food and feed industries, castor oil used in cosmetics, or increasingly popular oil from soybean seeds.
Briefly about equipment – types of oil presses
The device used to obtain oil from oilseed crops is, as one might easily guess, an oil press. However, as is often the case, the matter is slightly more complex, and several types of such machines are available on the market. Oil presses are divided into several types:
Screw presses – most commonly used in industry, they press oil using
a rotating screw, ideal for hot and cold pressing.
Hydraulic presses – use hydraulic force to squeeze oil, ideal for producing cold-pressed oils, characterized by higher oil quality.
Disc presses – use rotating discs to squeeze oil, used in medium-scale production.
Solvent extraction presses – use chemical solvents, enable high efficiency, but reduce oil quality.
Hot or cold?
When talking about types of oil presses and methods of obtaining fats from seeds, it is impossible to avoid the basic distinction: hot pressing and cold pressing. Does it matter? The answer is… yes – if we are talking about oil produced for food purposes. Cold-pressed oil is considered healthier than hot-pressed oil, mainly due to differences in temperature and the production process. In the case of cold pressing, raw materials (i.e. seeds) are not heated above 40–45°C. This allows most valuable nutrients to be preserved, such as unsaturated fatty acids (omega-3, omega-6), vitamins (e.g. vitamin E) and antioxidants. Thanks to this, the oil retains its full nutritional value and has a beneficial effect on health, supporting the cardiovascular system, immune system and skin.
Hot pressing, as the name suggests, involves a higher temperature (often above 100°C), which leads to the loss of many nutrients and a reduction in oil quality. This process may also cause the formation of unfavorable compounds, such as oxidized fatty acids, which are harmful to health. It is worth noting, however, that hot-pressed oils have a longer shelf life. Their nutritional value, however, is much lower.
Cold-pressed oil is therefore definitely a better component of the daily diet. In the case of oils used in crafts or preservation, pressing temperature does not play such an important role. Want to learn more? We recommend our article about cold-pressed oils – here.
What else does oil quality depend on?
Although the pressing method is crucial for the properties of the final product, there are a number of other factors that affect the quality of the finished oil. Of course, the type of raw material is important – healthy, mature seeds or fruits yield better oil – this is logical. Seed moisture is also significant; too high moisture may deteriorate oil quality. Pressing speed and time also affect the final product – a prolonged process can lead to oil oxidation.
How to start pressing oil?
Oil pressing is an undertaking that can be carried out on various scales – from local production for personal use to extensive production lines focused on profit and optimization. Regardless of personal preferences regarding production size, at the beginning it is worth answering the question about the preferred raw material and its availability.
The next step is choosing the appropriate equipment. Screw presses, hydraulic presses and smaller models for cold pressing are available on the market, which are more suitable for home use or small farms. It is important to choose a device with appropriate capacity that will allow efficient pressing depending on the production scale. The next stage is preparing the raw material, that is cleaning the seeds from impurities and possibly drying them. It is also worth paying attention to the quality of the raw material, because the quality of the final oil depends on it.
It should be remembered that after pressing, the oil requires filtration to remove seed residues. You can also choose a oil pressing and filtration set – which already has a built-in filter, thanks to which it immediately separates impurities and residues. It is also important to ensure proper storage conditions – the oil should be stored in a cool, dark place to prevent oxidation. Finally, it is worth becoming familiar with the regulations regarding oil production and sale in order to legally conduct business.
