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Do Mountain Valley Botanic’s hydrosols contain any preservative?

We do not add any chemical preservative to our hydrosols.  We take great care in preserving the quality, safety, and integrity of our hydrosols by sanitizing our distillation equipment, our collection funnels and vessels, and anything else that touches our hydrosol at any time.  Our hydrosols are filtered several times after distillation to remove any traces of essential oil that may harbor bacteria. Every container our hydrosols touch are disinfected to avoid any contamination.  Our hydrosols are stored in a cold, dark environment to keep them at their highest quality.

Why do you store your hydrosols in clear glass instead of brown glass?

For long term storage, hydrosols should be kept cool and dark.   For short term storage, they are fine left your counter or in a cabinet.  We use clear glass to allow you to see your hydrosol to be certain it has not become contaminated.  A coppery pink sediment in certain hydrosols such as Tulsi and German Chamomile is common, this copper that has precipitated out of the hydrosol.  It has anti-microbial effects and is not a sign of contamination.

Use your hydrosols daily and you will use them long before the light will degrade them.  If you buy bulk hydrosols, only keep out what you'll use in the next couple of months.

Other hydrosols that come packaged in brown glass risk hiding the signs of contamination.  Clear glass gives a transparency of packaging and safety.

Is it common for a hydrosol to become contaminated?

We take great care in sanitizing our equipment, distilling our hydrosol to the proper pH, and follow Good Manufacturing Practices throughout the distillation and bottling process of our hydrosols.  We have never experienced a contaminated hydrosol from properly cared for hydrosols.

However, in the name of science and research, I have purposefully contaminated samples, used poor bottling sanitation practiced, and other common things that may happen to an unpreserved hydrosol and tested the results.  Contamination can happen easily, and fungal and bacterial growth can happen quickly if proper protocols are not followed.  This is why I have strict sanitation protocols and test to be certain these protocols work.  We recommend applying hydrosol through the use of a spray applicator.  

How do you know these un-preserved hydrosols are safe?

Our hydrosols are routinely inspected and tested for contamination.  The final inspection is yours, the glass is clear and you can visibly see that your hydrosol is the appropriate color (see below for more information).  There are many inherent aspects of a hydrosol that make it safe, if properly distilled, filtered, and cared for.  Most hydrosols are slightly acidic, with a pH of 4.5-5.0; this acidic nature makes it resistant to contamination.   The sanitary care of hydrosols keeps it free from contamination.  

What color should my hydrosol be?

Most hydrosols are clear with a few exceptions.  Tulsi and other basils will have a light pink hue, they will also develop a coppery sediment.  This sediment is normal, it is copper from the distillation process that precipitates out over time.  This soluble copper is thought to be why these hydrosols have an extended shelf life.  German Chamomile hydrosol is light blue when fresh and quickly turns to a pale yellow.  German Chamomile also experiences some copper precipitation, to a lesser degree than the chamomiles. 

Do I need to use a preservative if I am using a hydrosol as an ingredient?

As soon as you add any other ingredient to a hydrosol, you need to either use it immediately or preserve it according to your formulation.

Do hydrosols expire?

Yes, hydrosols generally expire about 18 months from their distillation or 6 months from purchase.  When they expire, they fade in scent and potency.  So they do not "go bad" but rather become weaker and weaker until they resemble distilled water.  Some hydrosols last longer than others.

How do I know when my hydrosol will expire?

Every hydrosol should have a small batch ID sticker on it.  The last 2 numbers are the year it was distilled.  For exampled TLS02-22 was distilled in 2022 and is best used by the end of 2023.

Why does my recent purchase smell different than my last?

The seasonal nature of both plants and distillation brings many variables to each batch.  We do our best to keep harvest conditions and distillation times and temperatures consistent but there will be subtle differences between each distillation.  If you are unhappy with your recent purchase, reach out and let me know.

Can I get a sample of a current hydrosol?

If you'd like a sample of any of our hydrosols, please contact me at

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