The Science Of Scents: Cologne's Key Ingredients

Cologne is a perfume originating from Cologne, Germany. It typically contains a mixture of essential oils, alcohol, and water. The specific essential oils used vary across formulations and determine the unique scent profile of each cologne. These oils are usually extracted through steam distillation, cold pressing, or solvent extraction. The type and concentration of alcohol used can also affect the scent's intensity and duration. The amount of water in a cologne can influence its strength, with higher water content resulting in a lighter, more subtle fragrance.

Essential oils

Colognes are typically made with a blend of essential oils, which are pure plant extracts and carry amazing properties for our bodies and minds. These oils are categorised into three types of notes: top, middle, and base. Top notes are the first scents you smell, followed by middle notes, and finally, base notes, which are the longest-lasting scents. When creating a cologne, it's important to blend these notes in the right ratios to create a harmonious fragrance.

Top Notes

Top notes are usually citrusy or green scents, such as bergamot, grapefruit, lemon, lime, mints, lemongrass, rosemary, coriander, and cardamom. They can also include floral notes like lavender and chamomile. These notes are fleeting and volatile, but they are essential in creating a well-rounded fragrance.

Middle Notes

Middle or heart notes form the heart of the fragrance and give it depth and body. They are usually floral notes like rose, gardenia, jasmine, and tuberose, but can also include spices like cinnamon, cardamom, and nutmeg. Middle notes make the fragrance more vibrant and alive, and it's important to carefully balance them to avoid creating an overpowering scent.

Base Notes

Base notes are the strongest and longest-lasting scents in the fragrance. They include essential oils derived from barks, beans, grasses, pods, resins, and roots, such as benzoin, frankincense, myrrh, oakmoss, patchouli, sandalwood, and tonka bean. Vanilla is also a popular base note as it evokes feelings of comfort and familiarity. When creating a cologne, it's best to start with the base notes and build the other notes around them to avoid overpowering the lighter scents.

Blending Essential Oils

When blending essential oils, it's important to experiment and create accords (harmonious sections of the cologne). You can start by diluting your chosen oils in perfumer's alcohol and using smelling strips to evaluate their aroma, strength, and intensity. This helps you understand how the oils interact with each other and create a balanced fragrance.

Examples of Essential Oil Blends

• Wild orange (top note), sandalwood (middle note), and frankincense (base note)
• Lemon (top note), cardamom (middle note), ylang-ylang (middle note), and vetiver (base note)
• Lemongrass (top note), basil (middle note), cedarwood (base note), and Douglas fir (base note)
• Bergamot (top note), lemon (top note), clove (middle note), and white fir (base note)
• Juniper, cypress, peppermint, and pine
• Fennel, bergamot, and cedarwood
• Clove, juniper, rosemary, and lemon verbena
• Spearmint, lime, juniper, and valerian
• Nutmeg, fennel, orange, and cedarwood
• Lime, Roman chamomile, and sandalwood
• Wintergreen, orange, and blue spruce
• Sandalwood, black pepper, and myrrh

Tips for Using Essential Oils in Cologne

When using essential oils in cologne, it's important to follow safety guidelines and maximum dilution rates to avoid skin irritation. Additionally, using a carrier oil like jojoba or sweet almond oil can nourish the skin and make the scent last longer. It's also recommended to store cologne in a cool, dark place to preserve the integrity of the fragrance.

Alcohol

There are three common types of alcohol used in cologne production: ethanol, denatured alcohol, and isopropyl alcohol. Ethanol is known for its quick evaporation, efficiently dispersing the fragrance. Denatured alcohol is similar but with additives that make it unfit for consumption. Isopropyl alcohol, which evaporates rapidly, is sometimes used in lower-quality fragrances, although it can slightly alter the scent and is thus less preferred for high-end colognes.

The concentration of alcohol in a fragrance determines its classification. Eau de Cologne typically contains 2-5% essential oils and a higher amount of alcohol, resulting in a lighter, fleeting fragrance. Eau de Toilette contains 5-15% essential oils balanced with alcohol for a moderate scent intensity and duration. Eau de Parfum has 15-20% essential oils and a lower proportion of alcohol, creating a more intense and longer-lasting fragrance. Perfume Extract is the most concentrated form, with 20-30% essential oils and the least amount of alcohol, offering an extremely long-lasting and potent scent.

Water

The American Society of Perfumers defines perfumes by the ratio of compound to alcohol, with eau de cologne defined as having 85% alcohol diluted by 15% water. The addition of water to cologne serves multiple purposes. Firstly, it reduces the manufacturing cost as water is cheaper than alcohol and is not government-regulated or taxed. However, water also improves the user experience. It lessens the harsh, drying effect of alcohol on the skin, making the cologne more pleasant when applied.

In summary, while water may reduce the price of cologne, it also enhances the fragrance and improves the user experience.

Natural ingredients

Essential Oils

Essential oils are concentrated plant extracts responsible for the distinct scent profile of a cologne. They are usually obtained through extraction methods such as steam distillation, cold pressing, and solvent extraction. Each oil carries unique aromatic properties, and understanding the different types of notes in a cologne is crucial.

Top Notes

Top notes are the first scents you perceive when applying cologne. They are typically light and refreshing, composed of citrus, herbs, or light floral oils. They evaporate quickly, setting the initial impression before giving way to the middle notes.

Middle Notes

Also known as heart notes, these emerge after the top notes dissipate. They are more robust and long-lasting, forming the core of the fragrance. Common middle notes include floral, spice, and fruit oils, adding depth and complexity.

Base Notes

Base notes are the lasting scents that linger after the other notes fade. They are rich and deep, providing a foundation that helps the fragrance last longer. Typical base notes include woods, resins, and musks, offering warmth and longevity.

Alcohol

Alcohol acts as a carrier for essential oils in cologne. It helps dissolve the oils and allows them to be evenly dispersed when sprayed. It also aids in the evaporation process, ensuring that the fragrance unfolds in layers over time. The type and concentration of alcohol can affect the scent's intensity and duration. Common types of alcohol used include ethanol, denatured alcohol, and isopropyl alcohol.

Water

Water is used to dilute the cologne and balance the alcohol and essential oils, creating a smooth and even blend. The amount of water can influence the strength of the cologne, with higher water content resulting in a lighter, more subtle fragrance.

Synthetic ingredients

Common synthetic ingredients include:

• Aliphatic aldehydes (found in Chanel No. 5)
• Ambergris (a natural ingredient reproduced synthetically)
• Musk (a natural ingredient reproduced synthetically)
• Lily of the Valley (a natural ingredient reproduced synthetically)

Synthetic perfume has allowed perfumers to more easily create their scents and requires less quality control. The introduction of synthetic chemicals has made the process faster and more affordable, allowing perfume use to become a part of mainstream practice.

Frequently asked questions