The acidity of olive oil is a chemical parameter that is used to determine the quality of the oil and should not be confused with the acidity of the flavor that is perceived sensorially. It is obtained through analysis in a certified laboratory.
A customer's question about acidity.
Recently a client asked me what brand of extra virgin olive oil he should buy taking into account the acidity . This person, like many consumers, was relating the term acidity to the flavor of the oil, assuming that a lower acidity would result in a more pleasant-tasting oil.
This is a very common mistake, and it is due to the large amount of misinformation about olive oil that exists on the internet and in society in general.
My response was:
“Don't worry, I give you two reasons to rest assured with your purchase:
- When referring to acidity in olive oil, we are not talking about a flavor characteristic that can be perceived when drinking it, such as the acidity of a citrus fruit, but rather a chemical parameter that is used to categorize it.
- All the oils sold on our website are extra virgin, and all extra virgin olive oils as a rule have the same acidity (less than 0.8%).
That is why I recommend that you take into account when choosing other aspects that will make you find nuances of flavor in the extra virgin olive oil that you are going to buy, such as the variety of olive, if it is an early harvest oil, the area from which it comes, etc.”
The client opted for a wonderful Picual from Jaén in a 5-liter bottle , which he is now happily enjoying on his toast every morning, without having to worry about the acidity.
Understanding acidity in olive oil.
Let's delve a little deeper into what this chemical parameter that determines the quality of olive oil really is.
The acidity in olive oil refers to the content of free fatty acids present in the oil . What are free fatty acids?
Let's try to visualize it so that it is easier to understand:
Imagine a bottle of olive oil, 98% of the total is made up of fatty acids, while the remaining 2% are other compounds. Of that 98% of fatty acids, the majority is the famous oleic acid (a monounsaturated fatty acid that has many health benefits) and a smaller part is linoleic acid and palmitic acid.
These fatty acids are formed in groups of molecules called triglycerides, but during the production process or during storage, situations may arise that damage this union and some free fatty acids remain, which do not join forming triglycerides.
To determine the quality of the oil, a chemical analysis is done that determines the amount of free fatty acids in the oil, and this amount is what we call acidity. In chemical terms, free acidity is calculated from the amount of fatty acids that have been released from triglycerides, the main lipid structure of olive oil.
The higher the acidity (that is, the greater the amount of free fatty acids in the sample), the lower the quality of the olive oil will be determined.
The result of the analysis will show us a figure of the amount of free fatty acids present in the total oil. We can find this figure in % or in degrees.
Example: The extra virgin olive oil that our client purchased had an acidity of 0.3%, which is a super low acidity and tells us about the great quality of the product.
Factors that affect acidity in olive oil.
The acidity of olive oil can be influenced by a variety of factors, including:
Quality of the olive.
The quality of the olives is a determining factor in the acidity of the olive oil. Olives that are damaged, affected by disease or that have been harvested later than they should usually produce oils with higher acidity. The olive is a tremendously sensitive fruit, so its proper harvest and handling are essential in the final result that will determine the quality of the oil.
Collection and processing methods.
Harvesting and processing practices also play a crucial role. Manual harvesting, or with techniques that prevent the olive from falling to the ground (flying olive), tends to be less harmful to the olives compared to other mechanical harvesting techniques, which can damage the fruit.
Furthermore, the time that passes between harvesting and grinding is very important, since it must be as short as possible. The olive, once it is picked, is very sensitive and spoils very quickly. So this will also show up in the acidity analysis of the final product; A delay in processing can increase enzymatic and microbial activity resulting in more free fatty acids in the olive oil.
The storage conditions of the olive and later of the oil.
The storage conditions of the olives before processing and the oil itself after extraction are essential. High temperatures and prolonged storage can increase the acidity of the oil and decrease its quality.
The extraction processes.
The method of oil extraction also plays a role. Cold extraction systems tend to produce oils that show less acidity in analysis compared to methods involving any type of heat. High temperature during extraction can cause the breakdown of triglycerides and the release of free fatty acids.
What degree of acidity should the oil I am buying have?
Acidity is one of the main parameters to classify olive oil. According to the International Olive Council (IOC), olive oils are classified as follows based on their free acidity:
Extra virgin olive oil: lower acidity 0.8%.
Extra virgin olive oil is the highest quality oil you can find on the market. It is pure olive juice, and as we have seen this is reflected in the acidity analysis. For an olive oil to be categorized as extra virgin olive oil, it must have an acidity of less than 0.8%.
Virgin olive oil: acidity less than or equal to 2%.
Virgin olive oil is of poorer quality than extra virgin olive oil, and this is reflected in the acidity. In order to be categorized as virgin, it must not exceed 2% acidity. Although it is also olive juice, in its production or storage it shows defects that cause the acidity to be higher.
Any olive oil that exceeds an acidity of 2% cannot be categorized as virgin.
What happens with the rest of the oils? Mild olive oil, 0.4, olive pomace oil, etc.
In addition to extra virgin olive oil and virgin olive oil, in stores and supermarkets we find many other types of olive oil, which are also subjected to acidity analysis. The problem is that in this case we are talking about refined olive oils.
What are refined olive oils?
Refined olive oils are oils that have had to go through a refining process in their production that eliminates most of all the nutrients in the olive oil, as well as its flavor and aroma. This is more than 50% of the oil consumed worldwide. During the refining process, a multitude of chemicals are used.
Within the refining process there is a technique known as Neutralization, in which using powerful chemicals the free fatty acids are separated and the acidity is left almost at zero. For these oils to be suitable for consumption, they are mixed with a very low percentage of virgin olive oil; the little acidity they present will be what this provides.
Hence, they have a lower acidity but also are of lower quality, since they are not juice from the olive.
-Olive oil: acidity less than or equal to 1%.
Under this simple commercial name are grouped those refined oils that in their production process have lost all the qualities and health benefits that extra virgin and virgin oils possess, and to which a little virgin olive oil is added so that they are suitable for consumption.
-Mild olive oil or 0.4: acidity less than or equal to 0.4%.
It is a commercial name given by the industry to use its low acidity as a commercial claim, but as we have seen, this low acidity is due to the refining process, so it is not a synonym for quality, but quite the opposite. .
The acidity is lost almost completely in the refining process, and the only acidity it has is provided by the small percentage of virgin olive oil that is added after refining to make it suitable for consumption. When this percentage is very small, it shows an acidity of 0.4%, therein lies the commercial trick, in such a way that in the eyes of the consumer it may seem that that 0.4 is synonymous with higher quality even than a virgin olive oil or extra virgin, but it is not like that.
There are brands that also use the commercial name “intense oil” to name their refined oils to which a greater proportion of virgin olive oil is added, and thus make the consumer think that it is a flavored olive oil. intense.
-Olive pomace oil: acidity less than or equal to 1.5%.
After grinding the olive, once the oil is obtained, there is a remaining percentage that constitutes the so-called wet fatty pomace or alpeorujo formed by water, skin, bone and remains of oil. This set goes through an extraction and refining process, which is then also mixed with a low percentage of virgin olive oil to give rise to olive pomace oil.
As with the previous oils, in the refining process it loses all its acidity and the percentage shown is due to the virgin oil added to make it suitable for consumption.
Look at the label before choosing your olive oil.
Can I see the percentage of acidity on the product label?
In many cases yes, but as with many other aspects of olive oil, the information is confusing. I'm going to explain why and I'm also going to show you exactly what you can look for on the label to be sure of what you're buying.
According to the regulations, it is not mandatory for the degree of acidity to appear on the label; it is information that the manufacturer can choose to include. If it is included, it must be accompanied by other data on the composition of the oil, such as the peroxide index, wax content and ultraviolet absorbency. This means that in those cases in which the manufacturer pleases to include this information, what we find is this:
This type of highly technical information on labeling, in my opinion, is not useful for the average consumer, since I really do not believe that the general public takes this data into account when choosing. Despite all this confusion, all is not lost, I am going to give you the information that will help you know what you are buying and so that you can consume your olive oil with complete peace of mind.
What should I look for on the label to know exactly the type of oil I am buying?
In order not to get lost in this sea of data on chemical composition, my recommendation is that you simply search for ONE PHRASE.
-If you are buying extra virgin olive oil or virgin olive oil, the label must show this phrase:
“Olive oil obtained directly from olives and only through mechanical procedures.”
This phrase will certify that our oil is a quality product, pure olive juice. If it is an extra virgin, the acidity will be less than 0.8% and if it is virgin, the acidity will be less than 2%. And at this point, look for one that is a better price for your pocket, or that provides nuances of flavor and aroma that you like the most and allow you to enjoy the experience more, such as an early harvest, an organic oil, etc.
-If you are buying a refined olive oil (which will come under the commercial name: olive oil, mild olive oil, 0.4 olive oil, etc.), the label must show this phrase:
“It contains a blend of refined olive oils and virgin olive oils.”
As you already know, this phrase will tell you that the acidity of this product is less than 1.5%, and even much less, as in the case of 0.4, but you already know that this low acidity is not due to its higher quality but to the loss of a large part of its composition and nutrients caused by the industrial refining process to which it is subjected. We are not looking at pure olive juice, but rather a poorer quality product, and no, you will not experience the nutrients of extra virgin olive oil, nor its flavor or aroma.
In short, acidity is a value to classify extra virgin olive oil and virgin olive oil.
Conclusions:
As we have been able to clarify in this post, the acidity in olive oil is an essential chemical parameter that reflects the quality of the oil and should not be confused with sensory acidity.
This quality parameter is essential to be able to classify extra virgin olive oils and virgin olive oils. But as we have seen, refined olive oils, which are of poorer quality, show lower acidity than virgin oils due to the refining process.
Factors such as the quality of the olives, harvesting and processing methods, and storage conditions play a crucial role in the acidity of olive oil .
