Unlocking Floral Fragrances: Techniques For Capturing Aroma From Blossoms

There are several ways to extract the aroma of flowers, including enfleurage, distillation, solvent extraction, expression, and steam distillation. Enfleurage is a method that uses fat or oil to absorb the fragrant oils from flowers. This process requires no special equipment and can be done at home. The flower petals are covered with fat or oil and left to infuse for several days, after which the scented fat or oil is scraped off and used as a perfume or fragrance. Another method is steam distillation, where steam is passed through the plant material, causing the aromatic compounds to be released and collected. This method is commonly used for extracting scents from lavender, rosemary, and eucalyptus.

Characteristics of Extracting Aroma from Flowers

Using oil to extract fragrance

One of the most common methods for extracting fragrance from flowers is through a process called enfleurage. This technique uses a layer of fat, such as animal fat or solid plant oils like coconut oil, to absorb the scent of delicate petals or blossoms. The process is quite intricate and time-consuming, requiring multiple layers of petals and fat to be carefully arranged and left to set for several days.

Step 1: Selecting Flowers

Almost any flower can be used for enfleurage, but some will produce a more noticeable fragrance than others. Roses, lilies, and carnations are all popular choices, with roses yielding a particularly intense scent. It is best to pick flowers in the early morning when their oils are at their peak. Choose blooms that are just beginning to open, as these contain the most fragrance.

Step 2: Preparing the Petals

Gently remove the petals from the flowers, making sure you have a generous amount. Place the petals in a zippered food storage bag and lightly tap them with a wooden mallet to bruise them and release their fragrance.

Step 3: Melting the Oil

For this step, you will need a glass bowl, preferably with a cover, and your chosen oil. Babassu oil or RBD coconut oil are excellent choices for enfleurage. Heat your oil until it becomes fully liquid, aiming for a temperature of around 80°F (26.7°C). You can also add a tablespoon of non-GMO Vitamin E to the oil and mix well.

Step 4: Combining the Petals and Oil

Place your petals in the glass bowl and pour the warm oil over them. Cover the bowl and keep it in a warm place, ideally maintaining a temperature between 75°F and 80°F (23.9°C and 26.7°C).

Step 5: Replacing the Petals

Every 12 to 24 hours, remove the petals from the oil and replace them with fresh petals. This process may need to be repeated several times until you achieve the desired fragrance level.

Step 6: Removing Excess Water

Once you are happy with the fragrance, use a pipette to remove any excess water from the oil.

Step 7: Storing Your Fragrant Oil

Store your flower-infused oil in a glass bottle and keep it in a cool, dry place. You can now use your fragrant oil in a variety of ways, such as creating your own perfume, scenting your home, or adding it to potpourri or crafts.

It is important to note that this process does not produce an exact replica of the flower's fresh scent. The fragrance may differ due to the denaturing of aromatic compounds during extraction. Additionally, always label your creations and practice good hygiene when handling any homemade cosmetics.

The enfleurage process

Enfleurage is a traditional process that uses solid fats to capture the fragrant compounds produced by plants. It is one of the oldest fragrance extraction methods, and while it is costly and inefficient, it is the only method that can be used to extract the scent from delicate flowers such as jasmine and tuberose without destroying or denaturing them. The process can be carried out using "cold" or "hot" enfleurage.

Cold Enfleurage

In this method, a large framed glass plate (or "chassis") is smeared with a layer of animal fat, usually lard or tallow, and allowed to set. The chosen botanical matter, usually petals or whole flowers, is then placed on the fat and its scent is left to diffuse into the fat over the course of 1–3 days. The process is repeated with fresh botanicals until the fat is saturated with fragrance. This procedure was developed in southern France in the 18th century for the production of high-grade concentrates.

Hot Enfleurage

In hot enfleurage, solid fats are heated and botanical matter is stirred into them. Spent botanicals are strained from the fat and replaced with fresh material until the fat is saturated with fragrance. This is considered the oldest known procedure for preserving plant fragrance substances.

Final Steps

Once the fat is saturated with fragrance, it is called the "enfleurage pomade". At this stage, the pomade can be sold as-is, or further processed to extract the fragrant molecules. This is done by washing the pomade with ethyl alcohol, then separating the alcohol from the fat and allowing it to evaporate, leaving behind the absolute of the botanical matter. The spent fat can be used to make soaps.

Steam distillation

To begin the steam distillation process, cut, chop, or blend the flowers of your choice into small pieces. This step is crucial, especially for home distillation, as it increases the contact between the plant material and steam, allowing for maximal extraction. Then, place the prepared flowers in a still with water and heat the mixture. The resulting steam carries both oil and water-soluble components of the flowers with it.

The steam travels through an enclosed system of tubes or pipes and undergoes a cooling process, returning to a liquid state now rich with the flower's aromatic compounds. Finally, the liquids are collected in a receptacle, where they separate into two layers: a bottom layer of water (hydrosol or hydrolate) and a top layer of oils (essential oils).

It is important to note that the steam distillation process may denature or alter the aromatic compounds due to exposure to high heat. As a result, the scent of the extracted essential oil may differ from the fresh flower's fragrance. Additionally, some flowers tend to clump together during steam distillation, making it difficult for the steam to pass through. In such cases, water distillation or water-and-steam distillation may be more suitable methods.

Overall, steam distillation is a straightforward and efficient technique for extracting the aroma from flowers. By following the steps outlined above, you can successfully capture the aromatic compounds and create your own floral essential oils at home.

Extraction with a chemical solvent

Chemical solvent extraction is a process used to separate aromatic compounds from raw materials. This method is particularly useful when extracting fragrance from delicate flowers such as jasmine, tuberose, and rose, as well as fibrous and woody plant materials.

The process involves the use of a chemical solvent, typically hexane, ethanol, or ether, to dissolve the aromatic compounds from the flower material. The flower material is submerged and agitated in the solvent, which can also dissolve hydrophobic substances such as wax and pigments, resulting in a waxy mass called a "concrete". The concrete is then subjected to vacuum processing to remove the solvent, which can be recycled for reuse.

The concrete is too viscous or even solid at room temperature, so another solvent, often ethyl alcohol, is used to extract the fragrant oil. This process, called "percolation", involves passing the alcohol through the concrete, which dissolves the fragrant low-molecular-weight compounds. The alcohol is then removed through distillation, leaving behind a concentrated fragrance oil called an "absolute".

This method of extraction is gentle on fragile, heat-sensitive compounds, allowing for the capture of a broader range of aromatic molecules. It also minimises the risk of damaging the flower material during the extraction process, making it suitable for delicate flowers.

However, one of the challenges of solvent extraction is the potential presence of residual solvents in the final product. Stringent purification steps are necessary to ensure product safety and quality. Additionally, the use of chemical solvents can raise environmental and health concerns, requiring proper handling, disposal, and regulatory compliance.

Expression

Citrus peels are cold-pressed, and the oil squeezed from the peel is collected. The oils extracted through this method are highly susceptible to oxidation and should be refrigerated and kept out of direct light.

• Collect your chosen plant material.
• Place the plant material on a surface.
• Use a mechanical press to extract the oils from the plant material.
• Collect the extracted oils.
• Store the extracted oils in a cool, dark place to prevent oxidation.

Frequently asked questions