John Myers
Which cooking oils are suitable for cooking, frying, baking? Which ones for salads and desserts? How do I recognize good oils? We summarize what you should know about oils.
The essentials in brief:
- The rough rule of thumb is: Use cold-pressed oils for cold dishes, refined oils for hot dishes. With some restrictions, however, cold-pressed cooking oils are also suitable for roasting and deep-frying.
- Store cooking oils in a dark and cool place. If no such space is available, preferably in the fridge.
- If you have to dispose of cooking oil, do it in a container over the general waste – don’t pour it down the drain!
Salads, frying, baking: which oils are best suited?
Edible oils have different properties depending on the type and manufacturing process. Strong olive oil goes well with other dishes than mild walnut oil, and cold-pressed linseed oil, unlike refined rapeseed oil, is not at all suitable for frying.
- Since refined oils are almost odorless and tasteless, they are particularly suitable for the preparation of all meals where the oil should not have any influence on the taste – whether sweet or savory, whether prepared cold or hot. They are also usually colorless or slightly yellow and therefore do not change the color of the food.
- Cold-pressed oils, on the other hand, have an intense aroma, reminiscent of the plants from which they were extracted, and are often intensely yellow or green in color. If you want to give your dish a characteristic aroma, cold-pressed oils are ideal.
Whether an oil is only suitable for the preparation of cold dishes or also for roasting, frying and baking depends on the fatty acids it contains and its smoke point:
- The higher the content of polyunsaturated fatty acids, the less it tolerates heat. For example, linseed oil is not suitable for roasting, deep-frying or baking. You should only use safflower and sunflower oil for hot dishes if it is a special frying oil made from specially cultivated varieties rich in oleic acid. These highly heatable frying oils are cold-pressed and then steamed.
- The lower the smoke point, the more likely it is that the oil will smoke during roasting and frying. Cold-pressed cooking oils have a lower smoke point than refined oils from the same plant species because they contain more free fatty acids. For example, the smoke points for cold-pressed rapeseed oil are between 160 and 180 °C and for refined rapeseed oil over 210 °C.
Oils for frying
Refined oils and special frying oils are generally suitable for frying and frying , as these oils can be heated to over 200 °C.
However, at moderate temperatures you can also use some cold-pressed vegetable oils. Namely when they have a high oleic acid content. This is particularly the case with olive and rapeseed oils.
But keep in mind that using cold-pressed oils will affect the taste of the food!
For cooking, steaming, simmering and braising, it is not critical which oil you use, as maximum temperatures of around 100 degrees are reached.
Optimal are 130-140 °C for roasting and 160-170 °C for deep-frying. At higher temperatures, the food does not cook faster, but the oil breaks down more quickly and more acrylamide, which is a health risk, is produced in products containing starch, such as hash browns or French fries.
Please note: If an oil has been heated too much so that it smells burnt and smoke forms, you should neither eat the oil nor the food prepared with it.
Tip: If you don’t want to do without the delicious taste of cold-pressed oil despite the high preparation temperatures, season the finished food with the oil of your choice before serving.
Oils for baking
Flavorless cooking oils that can withstand the high temperatures in the oven are particularly suitable for baking – i.e. refined oils.
You can also use cold-pressed coconut oil for a special aroma. Extra virgin olive oil gives pizza and bread a Mediterranean flavor.
Oils for cold dishes
Cold-pressed oils can develop their aroma best in cold dishes, for example in salads, dips and desserts. For example, try extra virgin olive oil instead of butter on the bread. The intense flavors of the different native oils can transform well-known dishes into completely new culinary experiences. Depending on the type of oil, sometimes a few drops are enough.
Cold-pressed or refined oil?
There are two processes for the production of fats and oils:
- the cold press
- the refining
With cold pressing, the oil is pressed purely mechanically from oil seeds or oil fruits without heat being supplied. This is very gentle and the typical taste and smell of the variety are retained. Solid components are then separated during cold pressing by filtering, allowing 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 marked. “Native” oils are natural, cold-pressed oils, which means that they have not been roasted or steamed beforehand.
During refining, oil is first pressed out of the oil seed under heat. The pressing residue then still contains oil, which can be extracted (dissolved out) with the help of solvents. However, the crude oil obtained in this way is inedible and must therefore be cleaned in several process steps – this is also referred to as refined. Undesirable substances are then removed, 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 undesirable substances, however, valuable compounds such as vitamin E , plant sterols and color and aroma components are also removed.
Refined oils are generally largely odorless and tasteless, have a longer shelf life and are also cheaper than cold-pressed oils. Compared to cold pressing, refining achieves a significantly higher oil yield. In addition, the quality requirements for the raw material are lower because the many treatment steps remove off-flavors and pollutants, for example.
Note: If a cooking oil isn’t specifically labeled as cold-pressed or virgin, you can assume it’s refined.
Are cold-pressed cooking oils healthier than refined ones?
no Cold-pressed and refined edible oils only differ enormously in their degree of processing and taste. However, the composition of the fatty acids, which accounts for the health value of the oils, is almost identical in cold-pressed and refined oils of the same type.
It is true that some of the desired fat by-products, such as vitamin E and phytochemicals, are lost during refining in addition to the undesirable ones. But if you eat a varied diet, you get enough of these substances from other foods.
How long can cooking oils keep?
How long edible fats and oils can be kept is determined by
- light
- warmth
- oxygen
The best before date is only valid as long as the bottle is closed – when the bottle is open you have to trust your senses. If the oil smells or tastes rancid, it should be discarded. Although this does not pose an immediate health risk, it spoils the taste of the food.
Depending on the type of oil and the storage conditions, you may notice that edible oils are rancid after just one to two months (e.g. native linseed oil) or only after one to two years (e.g. refined rapeseed and olive oil).
Attention: The best before date is not an expiry date! Cooking oils usually have a much longer shelf life in the unopened packaging – so test it first before throwing it away!
Shelf life of cold-pressed oils
Cold-pressed oils have the shortest shelf life in comparison. In a closed bottle, they usually last about nine to twelve months. If the bottle is opened, it is best to consume the oil within two months so that it does not go rancid.
Some cold-pressed oils can be used much longer after opening, for example virgin olive oil. Linseed oil, on the other hand, spoils very quickly: even unopened, it can go rancid after three to six months, and in opened bottles after about two to five weeks. It is therefore best to buy linseed oil only in small quantities.
Shelf life of refined oils
Refined oils generally have a longer shelf life. They can be enjoyed for up to two years in an unopened bottle , sometimes even longer. Once the bottle is opened, the oil has a shelf life of around six to eight months.
Store oils properly
Oils should generally be stored in a dark and cool place. A dark, cool pantry is ideal. If you don’t have such a space, place the oil bottles in closed cupboards to prevent premature spoilage from exposure to light. You can also always keep cooking oil in the fridge. However, some oils flake out in these cool temperatures. But that doesn’t do them any harm. As soon as the oil has reached room temperature, the flakes dissolve again. You just have to remember to take the oil out of the fridge a while before using it.
Storage of cold-pressed edible oils
Always store cold- pressed oils in a dark, cool place and tightly closed. After opening, storage in the refrigerator is ideal – a must for linseed oil. Also remove any oil residue from the neck of the bottle, as this spoils particularly quickly when it comes into contact with air. Then you can no longer so easily distinguish whether all the oil or only the outer remains are inedible.
Storage of refined edible oils
Always store refined oils in a cool and dark place.
Dispose of leftover cooking oil properly
Do not pour fats and oils down the drain or toilet, as they put a strain on the sewage treatment plants and increase the cost of cleaning the sewage. And: Since fat is not water-soluble, it is deposited on the drainpipes and can lead to blockages and bad odours.
Small amounts of old oils and fats that are typical for households can be carefully packaged (e.g. in the original packaging or in an old screw-top jar) and disposed of with the household waste (residual waste bin) : Solid fats (e.g. old frying fat) should be packed in a few layers of newspaper. You can dispose of larger amounts of leftover cooking oil at recycling centers.
