Hydrolats

Hydrosols (or hydrolat or floral water) comprise the water collected from distillation of plant material used to extract essential oils. They contain water-soluble plant extracts and usually contain a tiny proportion of the essential oil. Their properties are often similar to those of the corresponding essential oil, but owing to their dilute nature they are considered to be gentler. 

The essential oil is a pale yellow with a light, bitter-sweet floral odour. The absolute is darker and more viscous with an odour closer to the original flower. The main chemical components of the essential oil are the alcohol lin-alool (30-37%), the ester linalyl acetate (6-17%) and monoterpenes limonene (12-18%) and [3-pinene (12-15%). Also present geraniol (2-3%), nerol (1-3%), nerolidol (3-6%), citral and jasmone. Both the plant and the essential oil have many established uses. The essential oil is considered to be one of the most effective as a sedative, carmative and antidepressant and often used to treat insomnia. It is also claimed to be relaxant for smooth muscle (internal, involuntary muscles) especially those of the gut. Suitable for all skin types, both the essential oil and hydrolat are versatile materials for the aromatherapist. Considered safe as it is nonirritant and non-sensitizing and an example of a non-phototoxic citrus essential oil. 

Clays disperse easily in water, but not with hydrophobic oils. They are particularly suited for use with the hydrolats. 

The use of aqueous (water-based) plant products, especially the Hydrolats, is becoming more popular with widespread applications. Although many of these have been used for hundreds of years their composition and range of properties is still the subject of research. 

The definition and term essential oil is widely understood and accepted. However the associated aqueous products currently present a more confusing situation. The most commonly encountered names are Hydrosols, Hydrolats and Floral Waters. 

Hydrolat A term favoured in France and Germany. This is the aqueous product of distillation, it is the condensed steam that has passed through the plant material when extracting the essential oil. They are the true partial extracts of the plant material from the distillation process and may be considered to be a by-product of the volatile essential oil. 

Hydrosol The term commonly used in the UK and USA and often interchangeable with Hydrolat. However, hydrosol can be an imprecise name and does not always restrict itself to aqueous distillation by-product. Some hydro-sols are made by infusing the complete essential oil in water. 

There are many properties attributed to Rosa hydrolats. It has been suggested that their specific therapeutic properties may be linked to the % composition of functional group compounds present. This theory is improved but finds favour with many aromatherapists. 

Melissa officialis or lemon balm has a hydrolat with a lemony scent with a wide variety of both internal and external uses. Its culinary applications are widespread and other uses include skincare, insect bites, digestive disorders and menstrual problems. 

Melissa essential oil is expensive and difficult to distill as it contains many hydrophilic (water loving) molecules. This means that the correctly produced hydrolat has many of these molecules in its aqueous solution and its properties are similar to that of the essential oil. 

Box 7.25 shows the analysis of two samples of melissa hydrolat. Both samples are from reputable producers and illustrate variations in composition. These can be due to a variety of factors including the nature of the plant material used, the distillation parameters and the operating systems of the analytical method. 

Courtesy ofLen Price, taken from Understanding Hydrolats The specific Hydrosols for Aromatherapy. A Guide for Health ... 

Hydrosol (or Hydrolat) Also known as floral waters. The water collected when... 

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