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The trouble with Hydrosols

September 2, 2012

What could be better than a little rose hydrosol to gently cleanse and rejuvenate tired skin?  Well pretty much everything as far as we are concerned and don’t take that the wrong way, hydrosol are lovely in theory but in practice they are rare, expensive and difficult to manage as we shall see below. So, what’s a hydrosol again?

A picture of steam distillation from Everest Herbs:

The good.

Hydrosols are otherwise known as the water of distillation. Let me just give you an example to illustrate:

Lavender is picked from the fields when it is looking and smelling divine.  It is gathered up and popped into a large vat where water is added to make what looks like one almighty large cup of herbal tea.  The vat is then heated which boils the water and water leaves the vat as steam.  Now if you have the ‘perfect’ distillation vat the design will be such that pressure can build up a little to force the boiling point of water up to past 100c to help with the essential production……

Anyway back to the nitty gritty.  The water boils, steam comes off and with that steam are little molecules of oils.   Essential oil manufacturers collect that steam and condense it back from a gas to a liquid (by simple cooling) before collecting it. The water goes into one pot and the oils into another.

The water from the above experiment is the hydrosol and the hydrosol contains the water-soluble aromatic components of the plant being distilled.  Well, those that survive the process anyway.  This hydrosol is quite different in chemistry to the oil and is prized by some skin care manufacturers IF they can get it.

The bad.

Let’s just re-frame the notion of what a hydrosol is for a moment shall we.  A hydrosol is the water of distillation or in other words the waste.  I haven’t been to every essential oil farm in the world (I’ve seen around 10 I believe) but none of the ones I have seen are treating their waste like potential gold. Indeed when the idea of selling the hydrosol/ water was brought up with one of Australia’s largest speciality oil producers they thought I was having a laugh.

The fact that the water of distillation is waste is a huge clue to why farmers aren’t keen to invest further time in selling it:

* the water used  distillation doesn’t have to be purified, filtered or otherwise ‘cleaned’ to be used.  Now don’t go off thinking that they are using muddy swamp water but suffice to say, you wouldn’t necessarily drink it.  This makes setting up a distillery easier and cheaper for farmers but means that any hydrosols produced could be below par in terms of water quality.

* even where the water used is purer than an angels tears many farmers distill in outdoor barns/ sheds that are semi-open to the environment. This makes things like eliminating air-borne pollutants or controlling temperature next to impossible even if they wanted to.

* for many farms the collection vessels and handling procedures used for the water waste would need a complete overhaul which may make the whole process unviable.  A product which is close to 100% water provides microbes with an ideal home and so unless the production, packaging, storage and transport systems used are as clean as clean microbes could flourish.

* The end product would require very different testing and validating than the oils and would add even more costs to the process in order to ensure a quality product.

* much more hydrosol is produced than oil due to the nature of the procedure which means that if everyone kept and tried to sell their waste the price would plummet (supply vs demand) for this easy to make anyhow but tricky to standardize and preserve product.

* following on from the above it is highly likely that the hydrosol chemistry will be variable from batch to batch due to the difficulties in controlling what comes    Over with the water.  It is easier to monitor, measure and standardize  the oily bits as much research has been done into essential oil distillation conditions. The same cant be said for the water due to its ‘waste’ classification so you could get vastly different qualities of product each time you buy it.

The Ugly.

As if that isn’t bad enough the market for hydrosols isn’t without its cheaters. Many products are passed off as hydrosols to meet the price and quality expectations of cosmetic manufacturers and while not all are fakes some are! In order to make sure you have what you want the best thing is to check the source – are they reputable, production method and control standard – ISO, GMP certified/ certifiable if appropriate and not all farms will be but are still OK, the micro count (ask for a copy of the micro testing for the batch you are buying (it should be less than 1000 CFU with none of the usual nasties present), the plant – can you steam distill THAT?  Production date – how old is it?

So, what to do??????

A good hydrosol can be a great addition to your cosmetic creation BUT a bad one can cause mayhem in terms of micro contamination and wasted time, energy and money.  The key is to do your research and be prepared to get what you pay for as good hydrosols don’t come cheap (and are best bought as fresh as possible).  Buying local is also great if at all possible as that helps to ensure freshness.

12 Comments leave one →
  1. Miriana permalink
    September 2, 2012 4:55 pm

    To have a vat under pressure, generally the temperature would climb a little over the 100C or higher as the pressure was increased… so…of “the water-soluble aromatic components of the plant being distilled”…can any survive the process past 121C or 134C for certain times?
    ie: steam sterilising, thus ridding the floral water of microbes…or would that also destroy the aromatic component of the water as well???

    • RealizeBeautyEd permalink
      September 3, 2012 9:02 am

      The aromatic components come off at all different temperatures and it varies from oil to oil – it is called fractional distillation where each fraction comes off at a different temp. Therefore you aren’t waiting for everything to come through at 120C ish, just the less volatile and more substantive base notes.

  2. September 2, 2014 6:35 pm

    Hello! I have a question and I hope this post isn’t too old!!
    I went to use some of my Blackcurrent hydrosol today (which I keep in the fridge and opened 3 months ago) to find that it had growth in the bottom of the bottle. Aroma-Zone’s site says that, kept in the fridge and used within 6 months, the HS are fine to use. Obviously not. THat bottle went in the garbage, but to ensure my next HS’s remain contaminant-free, I will be adding 0.5% LG+. My question for you, O Knowledgeable One, is this. If the HS I use already has a preservative, and I use, say 30% of it in a face cream, shoudl I still use 0.5% LG+ in the cream, I should I decrease the amount, seeing as the preservative in the hydrosol is including in the overall composition?

    Thanks in advance for your help!

    • RealizeBeautyEd permalink*
      September 3, 2014 7:12 am

      Hi candice,
      Many ingredients that we use in cosmetic formulations are preserved, hydrosols are usually an exception and that is why as a general rule I tell people to be careful with them or not use them. It may be possible to add preservative to your hydrosol when you get it and that might maintain the shelf life for longer. If you do the you should still preserve the end product fully without discounting preservative unless you have done PET (preservative efficacy testing) and established a lower safe level.

      It is possible that the hydrosol when purchased is already exceeding the micro limit that your particular preservative can handle and like an ambushed army it would face an uphill battle to get on top of the microbes.

      There are hydrosols that can be stored and used for many months without needing preservation but those are quite rare and it is more usual that the hydrosols need preserving in some way.

      Good luck and thanks for the question.

  3. May 1, 2015 1:52 am

    Hydrosols are a great addition to a cosmetic. However, I would find someone who distills specifically for the hydrosol rather than for the essential oil. It is a slightly different process to get a quality hydrosol rather than an essential oil. Typically, distillers who distill for the watery distillate are more aware of microbial issues and do treat the hydrosol portion as ‘liquid gold’.

    • RealizeBeautyEd permalink*
      May 1, 2015 6:57 am

      I agree Cindy, finding that sort of person and working with them would be my goal. Thanks for the feedback.

  4. Tray permalink
    March 27, 2016 5:56 pm

    Just want to say the water doesn’t matter. It’s called a distiller for a reason. The water that comes out will be distilled.

    • RealizeBeautyEd permalink*
      March 29, 2016 12:49 pm

      Hi Tray, but there is no guarantee that it will stay that way if it isn’t preserved as the water isn’t just water, it contains dissolved oils which are carbon based and therefore nutritive for microbes. It is not unheard of for a hydrosol to fail a micro test.

  5. John permalink
    December 1, 2016 3:48 pm

    Hello, I have good news. Me and my team of master distillers (all 3 of us) love hydrosols, oils, and the earth. We are a completely sustainable, organic, company who have nothing but respect for the earth and the many benefits they provide us with. Needless to say, people have seen great results with our products because we do it right. We preserve every product of the distillation process and treat them with respect. Every single aspect of our process is done with great care and respect… So don’t get too bent out of shape quite yet!!! You will hear of us very soon!!!

    • RealizeBeautyEd permalink*
      December 2, 2016 11:54 am

      Dear John, I will do my best to avoid being bent out of shape quite yet and will wait to hear from you. I would be very interested in hearing about which hydrosols you can provide and your annual volume projections as it would be fantastic to know that there are good options out there. Times they are a changing 🙂

    • Anja Tompa permalink
      December 3, 2017 1:54 am

      Hi John, what is your company please and are you still doing this?


  1. Hydrosols - What The Face

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