What is cooking oil

Edible oils - which are suitable for what?

Cold pressed or refined oil?

There are two processes for the production of fats and oils:

  1. the cold pressing
  2. the refining

In the Cold pressing the oil is pressed purely mechanically from oil seeds or oil fruits without adding heat. That is very gentle and the Varietal taste and smell remains. During cold pressing, solid components are then separated off by filtering, allowing them to settle or using a centrifuge.

By the way: if the raw material is roasted before pressing or the oil is treated with hot steam after pressing, this must be labeled. "Native" Oils are natural, cold-pressed oils, which means that no previous roasting or subsequent steam treatment has taken place.

In the Refining oil is first pressed out of the oilseed with the addition of heat. The residue from the press then still contains oil that can be extracted (dissolved out) with the help of solvents. However, the crude oil obtained in this way is inedible and therefore has to be purified in several process steps - which is also called refined. This then removes unwanted substances, for example substances from the manufacturing process, but also pesticides and natural ingredients that would shorten the shelf life of the oil. In addition to the unwanted substances, valuable compounds such as vitamin E, plant sterols as well as color and aroma components are also removed.

Refined oils are fundamental largely odorless and tasteless, more durable and also cheaper than cold-pressed oils. Because compared to cold pressing, refining achieves a significantly higher oil yield. In addition, the quality requirements for the raw material are lower, since the many treatment steps remove off-flavors and harmful substances, for example.

Note: Unless an edible oil is specially labeled as cold-pressed or virgin, you can assume that it is refined.

Are cold-pressed edible oils healthier than refined ones?

No. Cold-pressed and refined edible oils only differ enormously in their degree of processing and taste. The composition of the fatty acids, which make up the health value of the oils, is almost identical in cold-pressed and refined oils of the same type.

Admittedly, in the refining process, not only undesirable but also some of the desired fat by-products are lost, such as vitamin E and secondary plant substances. But if you have a varied diet, you will get enough of these substances from other foods.

How long can edible oils keep?

How long edible fats and oils can be kept is determined by

  • Light,
  • Warmth and
  • oxygen

influenced. The best before date is only valid as long as the bottle is closed - you have to trust your senses when the bottle is open. If the oil smells or tastes rancid, it should be disposed of. This does not pose an immediate health risk, but it does spoil the taste of the food.

Depending on the type of oil and storage conditions, you may notice that edible oils are rancid after 1-2 months (e.g. with native linseed oil) or after 1-2 years (e.g. with refined rapeseed and olive oil).

Danger: The best before date is not an expiration date! Edible oils usually have a much longer shelf life in the unopened packaging - so test them first before you throw the oil away!