Hi, I'm new here so forgive me if I started this discussion in the wrong category. First of all I'd like to say I find Chemists Corner extremely helpful, educational and informative so a big thank you for that.
I am posting here because I can't find any answers to my dilemma elsewhere on the internet and I'm hoping that someone can give me some advice.
I make a natural shampoo out of soapwort to try to combat dry patches on my scalp as everything thing else I have tried does not seem to work. The recipe is as follows:
I boiled 2 cups of distilled water with 2 tablespoons each of dried soapwort root, dried marshmallow root and white willow bark. When the mixture has simmered down to about 1 cup, I strained it, poured it into a foaming bottle sprayed earlier with 99% Isopropyl Alcohol and let it cool down to below 50C. I then added Liquid Germall Plus at 0.5%.
The first time I made it, I didn't have a preservative on hand yet and it molded within 1 week. However this time with LGP, after 18 days it hadn't molded but I had decided to test it using Microcount Duo by Schuelke to see if the preservative was working. 24 hours after I smeared both sides of the dipslide with a cotton bud soaked with the shampoo, the total plate count side was completely covered with small red spots which, from what I could understand, means that it is full of bacteria although the yeast and mold side seems clear.
I kept the bottle of shampoo in the shower.
I understand that botanicals are hard to preserve, however I did not expect that after 18 days (probably even earlier) bacteria to grow with the inclusion of LGP at the maximum recommended rate.
So I suppose my question is, am I doing something wrong? If the preservative is the problem, is there a preservative someone can recommend for this recipe please, keeping in mind that I live in a European Union country?
Thanks in advance for any advice!