Information about Hydrosols ~ from Tony Burfield

NIRC Question: In the formulation of personal care items, is a hydrosol considered a natural ingredient and can it be included in the percentage of
natural ingredients in a formulation?

Tony Burfield : The bottom line is that I think that it is perfectly legitimate to count distillates as natural ingredients, and count the water content in the hydrosols themselves as natural, since most definitions of naturalness include the manufacture of commodities by physical processes. Physical processes include steam distillation & hydro-distillation, freezing, boiling, high vacuum distillation, fermentation, enzymic bio-transformation, frying, roasting, baking etc. etc.

If you consider the way that natural vinegar is manufactured traditionally - by recirculating a mixture of wine and water over birch twigs spread with colonies of Acetobacter micro-organisms - I don't see that as being so very different in principle from hydrosol manufacture, in that they both use added water to as part of a natural process. What I would object to is adulterating the hydrosol isolated at the end of the process by adding extra water, as selling it as 100% natural.

I would object to a hydrosol being manufactured from mixing up an essential oil plus water (some people also add surfactants or other solubilising agents) without the distillation process. Some unscrupulous traders do this to my certain knowledge.

Distillates are something different again - usually fruits or other foodstuffs hydro-distilled or steam distilled, often with the addition of alcohol, or sometimes solely with alcohol. Although something of a former art, I have just been given an old book on the technology of distillate production for the food trade dating back some 60 or more years. I have already collected others when visiting Mediterranean islands. Here again, added water is a vital part of the "natural process." It is difficult to separate the term distillate from hydrosol, except that in the old sense of the word, it usually related to a fruit flavoring and often involved alcohol.

Hydrosols or hydrolats are the isolated distillation condensate waters, either intentionally produced or produced as a by-product to essential oil production, where aromatic materials are steam or hydro- distilled. Hydrosols are used by aromatherapists, and are used in nebulisers, cosmetics & shampoos and to a limited extent in foodstuffs. Popular hydrosols include lavender water, orange flower water, kewda water etc. In India for example, kewda water (produced from male spadices of Pandanus odoratissmus flowers) is used for flavouring syrups, soft drinks & Moghlai cuisine. Little chemical data exists on the chemical make-up of many hydrosols, but an interesting paper by Platto A. & Roberts D. (2001) "The Aroma Quality of Lavender Water: a Comparative Study" Perf. & Flav. 26(3), 44-64 compared lavender waters from several different origins & determined amongst other things) that genuine lavender water distillation condensate could be differentiated from reconstituted water (diluted essential oil in water) by the absence of acetate esters. Customers of hydrosols should always demand a "Certificate of Naturalness" from the supplier. This will have a section showing the total percentage of the natural involved, and a listing of the percentages and identification of each additive, if any. If the
product is truly 100% botanically derived from the named source by a purely physical process (i.e. steam distillation) then it will indicate this fact - If the supplier is unable to do this, change to someone more professional [a template of a typical Naturalness certificate is available from Cropwatch on demand].

Some genuine 100% natural hydrosols are storage-stable, and the natural bacteriostatic/fungicidal properties associated with many essential oils are enough to maintain product integrity (for a short shelf-life period at least). However, wherever natural products with a high water content are produced, opportunistic micro-organisms may become problematic. Those of you who have experience of brewery, potable water or dairy work will know that problems can occur which can be very difficult to eradicate. It is also true that the essential oil in some hydrosols only show weak anti-microbial properties. The upshot of this situation is that individual floating
colonies of (often gelatinous) opportunistic fungi are frequently seen in hydrosols. This situation may require producers to add preservatives, stabilizers, anti-oxidants etc. to maintain the product in a fit state for later usage - these should be clearly stated on the label/accompanying literature or on the producer's website.

Returning to the specific question, the water content "as is" should be regarded as natural, and part of the product produced by an allowed physical process. It is true that more unscrupulous producers may physically add distilled or de-ionized water to adulterate the product - added water here would not be regarded as part of a natural physical process.

Be aware also that a carcinogenic group of compounds known as chloropropanols can be generated by steam distilling proteinaceous
material (as would be found in the aromatic leaves, stems, roots etc. of plants) with chlorinated mains water. Many specifications now stipulate a maximum chloropropanol content (especially 3-MCPD) for essential oils (there is an EU limit for foodstuffs) although the problem is particularly associated with products like soy & oyster sauces, or with sterilization of herbs etc.

Thank you Tony, Kelly and Deb!