Along with a high level of unsaturated fats, they contain additional substances that are important for our health.
Our bodies don’t have the ability to produce two essential fatty acids, omega-6 (linoleic acid) and omega-3 (alpha-linolenic acid), so we need to rely on food sources in our diets to assure adequate intake.
Vegetable oils can help us a lot here.
This useful liquid can only be gained from specific plants that allow the extraction of fat. These may be referred to as oil plants.
They can be divided into two main groups of plants that supply the fat via their fruits, or their seeds:
- Fruits (e.g. olive, avocado)
- Seeds (e.g. sesame, linseed, rapeseed, soy, sunflower)
The quality of the raw products, like olives or seeds, is as important as the production. The process of making oil is what makes all the difference.
The exclusive method that is allowed for the manufacture of natural oils is pressing or centrifugal technology, while refined oils may use chemical extraction.
Pros and cons of natural vs. refined oils
In contrast to unrefined oils, the production of which is aimed to be as unadulterated as possible, refined oils are run through an elaborate chain of production methods with lots of chemicals involved.
What unites both processes is the step that involves pressing the seeds. This takes place in so-called oil mills, whose main equipment is the press. But before anything else can be done, the seeds are cleaned, skinned (if necessary), and crushed.
Only then can the press extract the oil, separating the firm parts (called press residue) from the liquid.
The following step involves filtering any sediment that remains from the oil. At this point, the product that has been extracted is what we refer to as the “natural” variety of this common kitchen product.
It’s from here that the production of refined oils begins.
After pressing the seeds at high temperatures, they are:
Involves removal of lecithin, with the addition of phosphoric acid.
A.k.a. neutralizing, to remove free fatty acids (FFAs).
This involves chemically binding and filtering the remaining impurities out of the oil, using chemicals to control the color.
Removal of unwanted aromatic substances that affect the oil’s flavor, via high-temperature steam.
Removal of any remaining plant substances, to create characteristic flavors and colors.
If you compare these processes, you can see that making refined varieties is much more complex. Though producers say they try to create their products with consumers in mind, the fact that lots of chemicals are involved can’t be denied.
So, what is the result of this chemical process? Let’s take a look at the advantages and disadvantages:
|Natural Oil||Refined Oil|
|-Keeps its unique, natural flavor and color||-Can be heated to high temperatures|
|-No possible chemical content||-Longer shelf life than unrefined varieties|
|-Vitamins and healthy phytonutrients are preserved||-Neutral flavor for different uses|
|-Not suitable for high-temperature cooking, roasting, or frying||-Chemicals and solvents used during production|
|-Destruction of valuable vitamins and fatty acids|
|-Loss of nutritional value|
The majority of oil that’s produced is refined, to make cooking and storing easier and more user friendly. This type has a longer shelf life, and can be used for more purposes in the kitchen than natural oil.
On the other hand, natural oils still have their unique features, and they haven’t been treated with chemicals at all.
Therefore, they can sometimes be cloudier than refined types. Because they haven’t been bleached, they may still contain natural substances that make them appear less uniform in color.
What to do?
Well, it is a good idea to use different varieties of oil in your cooking, as a bit of a compromise. This way, you can benefit from the nutritional profiles and unique qualities of both oils.
Choose unrefined sorts for dishes that won’t come into contact with high temperatures. Processed oils will be perfect for use then, as they won’t start to smoke or smell.
Not all fat is alike: The fatty acid pattern of vegetable oils
Of course, the quality of cooking oil is an important aspect to consider when you’re determining which one to buy.
The fatty acid composition is also a deciding factor, when it comes to the oil’s health benefits and its heat stability.
So, what makes one variety better equipped to stand up to the heat than another?
Besides the refining process, it depends on the amount of fatty acids with a double bond that are found within the product.
To give you a quick primer, the various types include:
- Saturated fats – no double bond
- Monounsaturated fats – one double bond
- Polyunsaturated fats – two, three, or more double bonds
The higher the amount of polyunsaturated fats within oil, the more heat sensitive it is. This applies especially to walnut, linseed, and pumpkin seed oils, which shouldn’t be heated up at all.
In contrast, the more saturated and monounsaturated fatty acids found, the higher the suitable heating temperatures.
This is one area where refined oils outperform natural products – in their ability to be heated up thoroughly. Refined versions are much more stable at high temps, as a result of their chemical treatment.
High temperatures, like those required for deep frying onion rings or searing meat, are the key weak point for unrefined types. Once they have been heated up too high, they can start to smoke and develop an unpleasant smell.
At this point the polyunsaturated fats have decomposed, vitamins are destroyed, and – most importantly – harmful substances can emerge. This is reason enough to use the correct oil for the task at hand.
Read on to learn more about the most popular vegetable-based varieties, how they taste, how to use them, and how to store them.
Storing vegetable oils correctly at home
There are a few key points to remember when storing cooking oil at home:
1) A dark, cool place is best
Like many other products, keep this one away from direct light, and store it in a relatively cool place.
This doesn’t have to be the fridge, but many refined oils are now “winterized” during processing, so they will not harden in the refrigerator. However, there is no explicit need to keep them there.
2) Don’t buy more than you can use
Once opened, oil tends to become rancid quickly.
If you’re using it daily, there’s nothing to keep you from purchasing a nice stock of olive oil. But if you like to use a variety of different types and use them only once in a while, try to buy small containers instead.
3) Consider the bottles
Another tip is to keep an eye out for green or brown colored bottles.
These are preferable over transparent versions, because the shading provided by the darker hue will cause daylight and sunlight to have less of an impact on the contents of the bottle, resulting in a longer shelf life.
Now, let’s take a closer look at the many different varieties of fruit- and seed-based oils available in the market today.
10+ Cooking Oils and How to Use Them
The following characteristics refer mainly to unrefined versions of each specific type.
Refined varieties have often been stripped of their unique flavors and colors, so the differences between them are less significant. And the highly processed types can all be used for high-temperature cooking, too.
This guide will also show you what to expect when buying natural products, and how to get the most benefit out of them.
Rapeseed/canola– the basic choice
Rapeseed oil is a kitchen basic, made of crushed seeds of the plant.
You might not see rapeseed on the shelf, but you probably will find canola or even vegetable types – and the truth is, they’re the same thing. In the case of vegetable, it may contain a blend of rapeseed, soy, and other oils.
Although it is not suited for searing or roasting, it still offers lots of benefits.
It has a light yellow color with a subtle, neutral taste, and the unrefined variety offers a hint of nuttiness. It also stands out due to its high vitamin E content, with approximately 50 percent polyunsaturated fatty acids.
Olive– the Mediterranean go-to
Olive oil is one of the most popular varieties.
People appreciate the different flavor nuances it offers, as well as the potential health benefits of this Mediterranean specialty.
To find out about all of its characteristics and particular types, take a look at Foodal’s article on various quality grades and culinary uses of olive oil.
Soybean– the world’s favorite
This one is made of crushed soybeans.
Did you know that this is the world’s most important oil plant? It accounts for more than 50 percent of global oil production.
It has a high protein level, with a mild flavor and a pleasant smell. Therefore, it is often found in margarine.
Plus, it contains lots of unsaturated fats with those important omega-3s, too.
If you‘re looking for a subtle option without the strong nutty taste that other varieties offer, this should be your choice.
Walnut– the aromatic delicacy
If you’re into nuts, this one should become part of your cooking routine. It is made by rubbing the walnuts and then pressing them.
Two to three kilograms (about 4 1/2-6 1/2 pounds) of nuts are needed to produce one liter (or about a quart) of oil. This makes it an expensive delicacy.
It can have different flavor nuances, depending on the production procedure. If the nuts have been roasted before pressing, it will have an even more intense and rich aroma, plus a darker color.
What else is there to consider? It is very rich in polyunsaturated fats, and therefore one of the most sensitive oils you can find – so store it in the refrigerator, and consume it quickly.
Sesame– an Asian expert
The sesame plant is said to be one of the oldest oil plants worldwide.
Though it’s not on the U.S. list of common allergens,this is a particularly prevalent allergen elsewhere in the world.
Different varieties are available. If you prefer something with a more intense sesame flavor for seasoning, find one that’s made from seeds that were roasted before they were pressed.
The brighter variety, made of seeds that were not roasted, doesn’t have that strong, nutty aroma. Depending on what you are cooking, this may be the best choice.
The spectrum of fatty acids found in this type is excellent. With about 40 percent monounsaturated and 50 percent polyunsaturated fats, it is not only beneficial to your health, but also easier to store than other sorts.
This oil is an expert ingredient when it comes to Asian cuisine. Use it for cooking and seasoning vegetable, meat, fish, and rice dishes. Homemade soups and stir fries with a few drops of oil on top will gain that special something.
Pumpkin seed– an Austrian treasure
This special kind of oil is not made from the common squashes you might usually grow in your garden, or use in recipes. The plant this product is derived from is actually what’s known as the oil squash.
It is a specific sort, without the regular pulp and with almost skinless seeds, which are perfectly suited for pressing. The roasting process prior to that step helps to bring out an aromatic flavor.
Making this variety is not a piece of cake – about 25 squash are required to produce just a quart of oil.
But what does Austria have to do with it?
Well, this country is one of few places where this special squash is cultivated. Styria is a distinct region in Austria with a long tradition of growing these unique plants.
So, if you find a bottle that says “Original Styrian pumpkin seed oil,” you can be sure that it’s the real thing, produced in this area.
There is another element that makes this oil so special: When it’s made from roasted seeds, it will be thick, with a dark green color. Plus, this version is highly aromatic.
It should not be heated up,as it contains about 50 percent of those sensitive polyunsaturated fats. Instead, add it to dishes right before serving.
One of my favorite ways to use it is by topping a bowl of pumpkin soup with a few drops. Pair it with raw foods or vegetables, cream cheese, or salads for an amazing new flavor experience.
Argan– the Moroccan beauty
You might know this particular oil from cosmetics or hair care products. It has become known as an all-purpose weapon to combat dry skin and brittle hair.
But have you ever thought about adding argan oil to your food?
It is gained from the fruits (or rather, the kernels within the fruits) of the argan tree, which grows mainly in Morocco.
The extraction of argan oil is elaborate. The kernels, which are approximately the size of sunflower seeds, are roasted and ground by hand in stone mills. Water is added to the mixture, which is then kneaded to make a paste, until the oil leaks out.
Like walnut or pumpkin seed varieties, it is very sensitive to heat.
But if you like the idea of using one sort for different purposes, like seasoning and skin care, this one is a good choice. Just be sure to purchase oil that is labeled for culinary use – cosmetic varieties should not be eaten.
It has a fine flavor, with a subtle smoky note. Use arga oil in Asian or Middle Eastern dishes, and add it to salads, sauces, or different kinds of meat.
Sunflower– the neutral all-rounder
This one is extracted from the seeds of the sunflower. It has a mild flavor, and a wonderful yellow color.
You will sometimes find it as an ingredient in margarine, thanks to its positive impact on our health.
While the refined version is a good choice for high-temperature cooking, natural sunflower oil should only be used for low-temperature frying or sauteing.
Linseed/flax– the individual character
The oil that is derived from the seeds of the flax plant has a deep yellow color and a rich, nutty, and slightly bitter flavor. It blends well with dishes that have either a fruity or a mild touch.
Plus, it will boost your omega-3 intake, as it contains more than 65 percent of those important fatty acids.
But keep in mind: this one should be consumed quickly, because it has the most limited shelf life of all varieties. After a few weeks, it will become rancid and inedible.
Coconut– the exotic wonder
In contrast to all the other cooking oils that are discussed here, this one has a unique feature: it is not a liquid at room temperature. This is due to its high saturated fat content.
Of course, that’s assuming the temperature of your kitchen is not particularly warm. As it has a low melting point (approximately 77-86°F), it is often sold as a liquid in its tropical countries of origin, and may be liquid on the shelf in the summertime (or if you live in a warmer locale).
The process of extracting this product starts with crushing the pulp of the fruit, then pressing and filtering it.
Although it mainly consists of saturated fats (approximately 85 percent), it is not considered to be unhealthy by many nutrition experts.
The big difference between this and other cooking fats is that coconut oil has little in common with the usual source of saturated fats, which are derived from animals. Vegetable-based types offer a different spectrum of fatty acids.
A great plus in comparison to other types is the fact that it is perfect for baking, stovetop cooking, roasting, and even deep frying, because it can withstand temperatures up to 390°F.
It is also a good choice for jazzing up chocolate coatings for cakes or baked goodies, or for when you’re preparing fillings for chocolates or other candies.
Its mildly sweet flavor is great in sweet applications, and savory ones too.
Other vegetable oil varieties
- Made of skinned peanuts with different nuances, depending on the country of origin (U.S. or Asian countries).
- High amount of vitamin E and unsaturated fats.
- Made of safflower seeds.
- Golden yellow, with a mild and light aroma.
- Perfect for daily use, and in dressings or marinades.
- Not suitable for high heat cooking.
- Pale to golden yellow with a neutral, mild flavor.
- Rich in essential fatty acids.
- Mainly for use in cold recipes, but it can be used for baking or desserts, too.
- Pressed from dried grape seeds.
- Fruity aroma with a mild tart note.
- Made from the flesh of the palm fruit.
- Orange in color, with a slightly nutty aroma.
- Becomes rancid quickly.
- Controversial due to deforestation of the rain forests, high saturated fat content, and because of the strong demand for palm oil for use in foods, as well as by the cosmetic industry.
- Color can vary from light to dark green.
- Aromatic flavor.
- Healthy, with up to 85 percent unsaturated fats, plus vitamins A and E.
- Ideal for skin care, too.
- Rich in vitamins and healthy omega-9 fatty acids (a.k.a. oleic acid).
- Great for use in salads, or dishes that go well with nuts (compare to walnut oil).
As you can see, there are many different types of oil for culinary use. While the natural varieties provide distinct flavors and work best in cold applications, you can choose refined oils for high heat cooking, like deep frying or searing, or even baking.
Run out of your favorite oil in the midst of a baking spree? Learn some smart oil substitutions for baking here so you can get on with your heyday.
My advice? Try a few different natural varieties to find out which ones you prefer in your cooking. Vegetable oils can definitely help you to create full-bodied meals with lots of flavor nuances.
Do you already have a favorite? Tell me about your experience with natural and refined cooking oils, and how you work with them. Share your thoughts and opinions below.
Photo Credits: Shutterstock
About Nina-Kristin Isensee
Nina lives in Iserlohn, Germany and holds an MA in Art History (Medieval and Renaissance Studies). She is currently working as a freelance writer in various fields. She enjoys travel, photography, cooking, and baking. Nina tries to cook from scratch every day when she has the time and enjoys trying out new spices and ingredients, as well as surprising her family with new cake creations.