
Herbal distillates, also known as floral waters, hydrosols, hydrolates, herbal waters, and essential waters, are aqueous products of
hydrodistillation. They are
colloidal suspensions of
essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...
s as well as
water-soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solub ...
components obtained by
steam distillation or hydrodistillation (a variant of steam distillation) from plants and herbs. These herbal distillates have uses as
flavoring
A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive that is used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemoreceptors of ...
s and
cosmetics
Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural source ...
. Common herbal distillates for
skincare include
rose water,
orange flower water, and
witch hazel.
Rosemary
''Salvia rosmarinus'' (), commonly known as rosemary, is a shrub with fragrant, evergreen, needle-like leaves and white, pink, purple, or blue flowers. It is a member of the sage family, Lamiaceae.
The species is native to the Mediterranean r ...
,
oregano
Oregano (, ; ''Origanum vulgare'') is a species of flowering plant in the mint family, Lamiaceae. It was native to the Mediterranean region, but widely naturalised elsewhere in the temperate climate, temperate Northern Hemisphere.
Oregano is a ...
, and
thyme
Thyme () is a culinary herb consisting of the dried aerial parts of some members of the genus ''Thymus (plant), Thymus'' of flowering plants in the mint family Lamiaceae. Thymes are native to Eurasia and north Africa. Thymes have culinary, medici ...
are hydrosols that may be used in
food manufacturing industries.
Production
Herbal distillates are produced in the same or similar manner as essential oils. However, essential oils will float to the top of the distillate where it can be removed, leaving behind the watery distillate. For this reason, the term ''essential water'' is an apt description. In the past, these essential waters were often considered a byproduct of distillation, but are now considered an important co-product. The produced herbal waters are essentially diluted essential oils at less than 1% concentration (typically 0.02% to 0.05%). Several factors, such as temperature and a herb's growth cycle, impact the characteristics of a distillate, and therefore influence the timing of the distillation. Rosemary, for example, should be distilled in the peak of
summer
Summer or summertime is the hottest and brightest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, daylight hours are the longest and darkness hours are the shortest, with day ...
before it flowers.
Usage
1. Food industry: Herbal distillates are often used in culinary applications to add subtle flavors to foods and beverages. Their mild nature makes them ideal for infusing delicate flavors into dishes without the overpowering intensity of essential oils. Commonly used distillates in this context include rose water, orange blossom water, and peppermint hydrosol. Herbal distillates are also used to preserve food, and have been shown to be effective in achieving desirable effects, like reducing the degree of oxidation of some meats.
2. Cosmetics: In the cosmetic industry, herbal distillates are prized for their gentle, skin-friendly properties. They are used in a variety of products, including:
* Facial toners: Distillates like witch hazel and rose water help to balance the skin's pH, tighten pores, and provide hydration.
* Cleansers: Hydrosols can be incorporated into facial cleansers for their soothing and anti-inflammatory properties.
* Body sprays and mists: Herbal distillates are commonly used in body mists for their refreshing and aromatic qualities, as well as air fresheners.
3. Herbal Treatments: Herbal distillates are also employed in traditional and
holistic medicine for their therapeutic benefits. Due to their lower concentration compared to essential oils, they are often used for:
* Topical applications: They can be applied directly to the skin to soothe irritations, reduce inflammation, and promote healing. For example, lavender hydrosol is used for its calming and antiseptic properties.
* Inhalation: Certain hydrosols can be used in steam inhalations to alleviate respiratory issues and provide a sense of well-being.
* Internal use: Some distillates, such as peppermint and chamomile, can be taken internally in small quantities to support digestion and alleviate mild gastrointestinal discomforts.
4. Agriculture: Herbal distillates are also used as insecticides, herbicides, and antibacterial and antifungal agents in agriculture. Additionally, herbal distillates may be used in
allelopathy, with possible applications including the manipulation of the timing of sprouting (see
vivipary) and
germination
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...
.
5. Clothing: Herbal distillates can be added to water in a
clothes iron
A clothes iron (also flatiron, smoothing iron, dry iron, steam iron or simply iron) is a small appliance that, when heated, is used to press Clothing, clothes to remove Wrinkle, wrinkles and unwanted creases. Domestic irons generally range in o ...
to add a delicate scent into clothing. Since herbal distillates do not contain hard minerals such as
plastic
Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...
and
metal
A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...
,
it will also help keep clothing irons working properly for much longer.
Science
The science of
distillation
Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixt ...
is based on the fact that different substances
evaporate
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. A high concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when hum ...
at different temperatures. Unlike other extraction techniques based on
solubility
In chemistry, solubility is the ability of a chemical substance, substance, the solute, to form a solution (chemistry), solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form su ...
of a compound in either
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
or
oil, distillation will separate components regardless of their solubility. The distillate will contain compounds that vaporize at or below the temperature of distillation. The actual chemical components of these orange herbal distillates have not yet been fully identified, but plant distillates will usually contain essential oil compounds as well as organic acids and other water-soluble plant components. Compounds with a higher vaporization point will remain behind and will include many of the water-soluble
plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...
pigment
A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...
s and
flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Chemically, flavonoids ...
s.
Because hydrosols are produced at high temperatures and are somewhat acidic, they tend to inhibit
bacterial growth but not
fungal growth. They are not
sterile, and should be kept refrigerated to preserve freshness. Herbal distillates degrade over time and will degrade faster than essential oils, which are more stable.
Small-scale producers of hydrosols must be particularly aware of the risk of bacterial contamination and take steps to prevent it. Despite concerns that there may be significant amounts of
heavy metals
upright=1.2, Crystals of lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead
Heavy metals is a controversial and ambiguous term for metallic elements with relatively h ...
in popular herbal distillates, this has not shown to be the case.
See also
*
Orange flower water
*
Rose water
*
Witch hazel (astringent)
References
Books
* Firth, Grace. Secrets of the Still. Epm Pubns Inc; First edition (June 1983)
* Price, Len and Price, Shirley. Understanding Hydrolats: The Specific Hydrosols for Aromatherapy: A Guide for Health Professional. Churchill Livingstone 2004
* Rose, Jeanne. 375 Essential Oils & Hydrosols. Frog, Ltd, Berkeley, CA, 1999.
* Rose, Jeanne. Hydrosols & Aromatic Waters. Institute of Aromatic & Herbal Study, 2007.
{{Perfume
Distillation
Herbs
Essential oils
Flavor technology
Herbalism
Cosmetics
Perfume ingredients
Pharmacognosy