How Are Essential Oils Made? The Ultimate Guide

The quality and purity of essential oils largely depend on the method used to produce them. There are various techniques for extracting oils from plant material, including heat and heatless methods, each with its own advantages and disadvantages. 

As a buyer, having knowledge of the extraction process can help you make informed decisions when buying essential oils. This information will also help you to have a better understanding of how extraction methods affect the purity and potency of essential oils. 

In this article, we break down exactly how essential oils are made, provide insight into the quality control and safety of essential oils, and give an overview of applications and uses as it relates to extraction methods.

A Brief History of Essential Oil Production

Essential oils have been used for thousands of years for their potential therapeutic properties and beauty benefits. The earliest documentation of essential oil use comes from Persia, India, and Egypt. In those times, essential oils were extracted by soaking plant material in fatty oils until they absorbed the essential oil from the plant’s leaves, roots, or flowers. This method allowed for the gradual absorption of aromatic compounds, resulting in fragrant blends.

In Arab culture, essential oils were extracted using a distillation process. The plant material was mixed with ethyl alcohol fermented from sugar and then heated. The natural separation of the mixture allowed for the collection of the essential oils. This distillation technique made its way to Europe during the Middle Ages, and the oils became popularly sold in European pharmacies for their potential therapeutic properties. 

In Southern France, the primary method of essential oil extraction involved using cold fat. This technique was known as enfleurage, and it involved laying the plant material over tallow for 1 to 3 days. The fat would absorb the oils from the plant, creating a pomade for use in skincare. However, this process was time-consuming and yielded only small quantities of essential oils. 

Nowadays, essential oils are produced on a much larger scale, using multiple techniques such as steam distillation, solvent extraction, and cold pressing. These methods have made it possible to produce high-quality essential oils in large quantities, making them more accessible to people all over the world. 

Common Extraction Methods

The process of extracting essential oils is highly dependent on various factors, including the desired amount of oil to be extracted and whether heat is used. Below, we will explore the most popular methods of extracting essential oils and discuss the key benefits and drawbacks of each technique. 

Steam Distillation

Steam distillation is a commonly used method for extracting essential oils from plants. In this process, steam is used at temperatures around 212°F, which breaks down the plant material and releases the aromatic compounds. 

The steam carrying the essential oil is cooled and condensed into a liquid form. The resulting liquid is a mixture of essential oil and water, which is then separated by decantation or separation. This technique is typically used for extracting essential oils from plants such as eucalyptus and lavender. 

Step-By-Step Steam Distillation Process

Steam distillation is a multi-step process that involves the use of specialized equipment. The following is a brief outline of the steps involved in this procedure:

1. Preparing the plant material: The first step involves collecting and preparing plant material by cleaning it to remove any dirt or other impurities and drying it to remove excess moisture.
2. Loading the distillation instrument: The plant material is then loaded into a distillation instrument, typically made of glass, due to its transparency and heat resistance.
3. Steaming the material: The instrument is then heated, and steam is introduced to the plant material, causing it to break down and release the essential oils.
4. Collecting the condensation: The essential oil and the steam are carried through a condenser, which is typically a glass tube. The steam travels through this apparatus, in which it is cooled and converted back into liquid. The oil is then collected in another container while the remaining water drains.
5. Separating the oil: In some cases, the oil may need to be separated from any remaining water or impurities. 

Pros and Cons of Steam Distillation

One of the major benefits of steam distillation is that it is a solvent-free method. This chemical-free technique makes it environmentally friendly and safe for human use. Steam distillation also helps to preserve the natural aroma of plant materials, as it doesn't involve any harsh chemicals that could damage or alter the chemical composition of the oils. 

In addition, steam distillation is a widely used, simple, and accessible method of extracting essential oils that has been used for centuries, making it a reliable and safe technique. 

However, steam distillation also has drawbacks. Some compounds, especially those that are heat-sensitive, may be degraded or altered during the process. This method can also be time-consuming, especially for materials with low oil content or when large quantities of plant material are involved. 

Cold Pressing

Cold pressing is an extraction method that involves the application of physical pressure to the plant's roots, leaves, or flowers to release the oils. Unlike other extraction methods that use heat, this method does not involve any temperature changes, making it safe for plants with low boiling points. 

This feature of cold pressing preserves the constituents present in the essential oils, as they are not degraded due to high temperatures. As a result, essential oils extracted through this method have a high nutrient composition that is well-preserved, making them ideal for use in various applications. 

Steps Involved in Cold Pressing

To extract essential oils from plant material using a hydraulic press, there are several steps involved, including:

1. Gathering and drying the plant material: The first step is to collect the plant material and dry it thoroughly to remove excess moisture.
2. Preparing the material: Once the plant material is dry, it needs to be prepared for pressing. This involves crushing or grinding the material into smaller pieces to increase surface area.
3. Adding the material to the press: The prepared plant material is then added to the hydraulic press. 
4. Applying pressure: The hydraulic press applies pressure to the plant material, which causes the oil to be released.
5. Collecting the oil: The oil released from the plant material is collected in a container placed below the hydraulic press. Once all the oil has been collected, it can be filtered and processed as needed.

Pros and Cons of Cold Pressing

Cold pressing has multiple benefits, including the fact that it is heat-free. The absence of heat helps retain delicate compounds that may degrade at higher temperatures, preserving the oil's potential therapeutic properties. 

This technique also preserves the aromatic compounds present in the essential oil, ensuring that the final product maintains its natural fragrance. In addition, this technique involves minimal processing and no added solvents, ensuring the resulting oil's purity.

A disadvantage of cold pressing is its limited applicability to plant materials with high oil content. Cold pressing is most effective for extracting oils from fruits with lots of oil glands, where the pressure applied can efficiently release the essential oil. This drawback may restrict the range of plants that can be effectively processed using this method.

Solvent Extraction

Solvent extraction is a method used to collect essential oils from plant material using organic compounds like ethanol, hexane, and acetone. It is useful when dealing with delicate flower parts that cannot tolerate the high temperatures used in steam distillation. 

The process involves immersing the plant material in the solvent, which attracts and dissolves the aromatic compounds. The resulting mixture is then gently heated, and filtration separates the essential oil from the solvent. This method is widely used in the perfume industry to extract fragrant oils that can provide long-lasting scents.

Process of Solvent Extraction

Here are the steps involved in solvent extraction:

1. Grinding the plant material: The first step is to grind the plant material into small pieces to increase the surface area for better extraction.
2. Soaking in the solvent: Next, the plant material is soaked in a solvent like hexane or ethanol. The solvent helps dissolve the essential oils and other compounds in the plant material.
3. Separating the oils from the solvent: The mixture is then added to a centrifuge, spinning at high speeds to separate the oils from the solvent. The oils are collected in one container, while the solvent is collected in another.
4. Collecting the mixture: The oil and solvent mixture is collected and subjected to further processing to remove any impurities or unwanted compounds.

Pros and Cons of Solvent Extraction

Solvent extraction is known for yielding large amounts of essential oils, making it a popular choice among manufacturers and producers. In addition, it is a low-heat process that helps preserve the oils' natural properties. 

One concern is the residue left behind on the oils after extraction. Solvent extraction can introduce impurities or contaminants into essential oils, affecting their purity and potentially diminishing their therapeutic benefits. Traces of solvents may remain, compromising the quality of the oil. If not completely removed from the final product, these solvents may cause allergies in some individuals. 

It’s important to note that high-quality facilities implement rigorous purification processes to carefully filter out any remaining solvents, ensuring the purity and safety of the essential oils.

Quality Control and Safety

Essential oil extraction requires extensive quality control and safety measures. Implementing quality control practices ensures that the oils are pure and free of contaminants, making them safe for therapeutic use. High-quality oils also increase client satisfaction, which is crucial for business success in the aromatherapy industry.

The quality of plant material and growing conditions are two factors that affect the quality of essential oils. Plants grown under adverse conditions, such as exposure to pesticides and other environmental toxins, may produce oils with contaminants that are harmful to human health. 

Therefore, it is important to source plant materials from reputable suppliers and ensure that they are grown in ideal conditions. For example, all suppliers at Wholesale Botanics are carefully evaluated to ensure that the oils are sourced from sustainable fields, farms, and forests.

Storage conditions also affect the quality of essential oils. Essential oils are sensitive to air, light, and heat, which may affect their chemical composition and quality. Heat and light exposure can cause chemical changes in essential oils, leading to the breakdown of existing compounds. 

Prolonged exposure to oxygen present in the air can lead to oxidation of molecules in the essential oil. This process breaks down the chemical compounds in the oil, causing it to lose its potency and therapeutic properties. Storing essential oils in a cool, dark, and dry place prevents oxidation and degradation.

Essential Oil Quality Assessment Techniques

Various testing methods are used to validate the quality and purity of essential oils. Gas Chromatography Mass Spectrometry (GC-MS) is one of the most commonly used methods for testing the purity of essential oils. This technique separates the individual components of the oil and identifies any impurities or contaminants. 

Stability testing evaluates the quality and shelf life of oil over time. This method involves subjecting the oils to different conditions, such as light and temperature, to assess their physical and chemical stability. This process helps determine the oils' shelf life and storage requirements, ensuring product quality and safety for consumers. 

Refractive index analysis is another method used to determine the purity of the oil by measuring its refractive index, which is a measure of how light bends when passing through the oil. This technique offers insights into factors such as composition and potential contaminants present in the oil. 

Applications and Uses

The extraction method used to produce essential oils directly influences their applications and uses due to its impact on the oil's composition, purity, potency, and aroma. 

What Are Essential Oils Used for?

Essential oils are used in aromatherapy and facial, hair, and body care. Aromatherapy is using essential oils to promote physical and emotional well-being. Essential oils are often used in diffusers, bath products, and massage blends to help calm the mind and body. 

They can also be used in facial care products to help nourish the skin, and to potentially address certain skin concerns. In hair care, essential oils may promote hair growth and help soothe an itchy, irritated scalp. Regarding body care, essential oils are typically used in body lotions, body scrubs, and bath products as they may nourish and hydrate the skin.

The Impact of Extraction Methods on the Applications of Essential Oils

Many people using oils on their skin and hair opt for oils that are obtained through solvent-free methods of extraction. Consumers may want to minimize their exposure to synthetic chemicals and residues that may be present in solvent-extracted oils. 

At Wholesale Botanics, we use solvent extraction to preserve the aromatic compounds and attain high oil yields in some products, such as benzoin oil. We take great care in testing and regulating each stage of the process to ensure that the final oil is free from impurities, prioritizing safety and quality.

Cold pressing does not involve the use of chemical solvents in the extraction process. This method is often used for citrus oils, such as lemon, as well as for oils extracted from nuts and seeds, such as almond and jojoba oil. Many consumers opt for oils extracted using this method because it preserves many of the nutrients in the oils so that it can have optimal therapeutic effects on their skin and hair. 

Steam distillation is also a gentle, solvent-free method of extraction that results in high-quality oils. Oils extracted using this method are also widely accessible online, making them a common choice for DIY enthusiasts.

To note, not all essential oils are of high quality. As mentioned briefly, the quality of the oil can vary depending on the extraction method used and the quality of the plant material. It is important to only purchase oils from companies that regularly test them to ensure their purity and quality. 

Embrace Peace of Mind With High-Quality Essential Oils

Several techniques are used for essential oil extraction, including steam distillation, solvent extraction, and cold pressing. Steam distillation and cold pressing are the most popular, safe, and reliable methods for producing high-quality essential oils. 

At Wholesale Botanics, we pride ourselves on using the highest-quality extraction techniques to produce potent essential oils. Our oils are made in clean and vetted facilities, and we test them thoroughly to ensure they meet high-quality standards. We also provide a Certificate of Analysis with each oil batch that confirms the quality of each oil so you can be confident about the products you purchase.