Often on forums I visit, people will post formulations, or little experiments they are doing. 

We get some lovely looking products – creams and lotions, shower gels etc.  There is generally one person that might point out that there is ‘bug food’ (normally without even knowing the level of said bug food) and that they should make sure their preservative will 'cover it’.  

More often than not they are talking about things like starches, floral waters and  honey.

 In this post I am going to explain, using rose water as an example, why generalising about ingredients is not particularly helpful and can be a bit of a problem when formulating.

Firstly, there is the issue of testing our products.  We only know for sure if our preservative will 'cover' anything by testing them.  

Secondly, in most water containing products there are enough ingredients that are 'bug food'  i.e. emulsifiers, butters and waxes, that can put a strain on a preservative.

So, what is the problem?

Let’s look at the issue more fully using the example of floral waters or hydrolates.  Floral waters like rose water first and foremost contain water, small amounts of essential oil and  in some cases it has some solid vegetable matter.  We all know that bacteria, yeast and mould need moisture to survive. But water is found in large amounts in most of our water containing formulations.

Water is unavoidable in this case, and as we know, water is the life force of every organism, we just have to make sure that starting out our water is clean.  The same applies to other ingredients.  

As stated, hydrolates  contain some essential oils leftover during distillation. In the case of Rose water, it will probably have a large amount of phenyl ethyl alcohol (PEA).  PEA or phenethyl alcohol is quite a strong antimicrobial so is likely to help keep the product clean of some bacteria. But what about the solid matter?  

Well the solid matter, doesn't so much as provide food for microbes, as provide a home for them; by using a floral water with lots of solid vegetable matter we risk introducing microbes to our formulation, contaminating it before we have even finished producing it!

But the thing is, the levels of solid matter really depend on the individual floral water, how well filtered and how clean it is.  Recently I have been on a bit of a hunt to find a strongly scented rose water that is preservative free.  I have noticed there is a great variety in their quality –some have been preserved, some not, some have been  cloudy and some with sediment and some crystal clear. Some are strongly scented indicating a lot of essential oil and some have barely no scent at all.   

I have purchased some preservative free floral waters from skincare brands that have a period after opening of 6 months (which indicates it would have been tested) and have been extremely strong in scent.   There are also ones branded for the food market that would have also had stringent tests conducted.  This also leads me to believe that it really does come down to the quality and purity of the product. All this taken into consideration,  I have seen many, many finished products on the market (emulsions, solutions etc) containing high levels of floral waters, so it is not impossible to formulate with them safely!

One thing is for sure, when you are purchasing a floral water, make sure you get the certificate of analysis which will tell you exactly how clean your product is.  If you have the capability it might also be a good idea to test your floral water for contamination, and it also goes without saying, if you want to sell then you need to test that your preservative works and overall, that your product is safe.

Happy formulating!