As Ann Harman states in her book Harvest to Hydrosol, "Anyone who has worked with the medicinal waters would agree that they are a multi-layered healing modality." And "When using hydrosols for therapeutic purposes it is imperative to educate yourself...to understand the difference between the types of hydrosols that are offered commercially.1" This brief post seeks to help you do just that - understand what it is you are really getting when you purchase a hydrosol.
As many of you know, a quality hydrosol is NOT a byproduct of distillation for essential oils. It is THE product you intend to create. You see, hydrosols may contain anywhere between 0.01 - 0.02% of water soluble volatile components - chemical components that are similar to those in found in essential oils. The volatiles contained in hydrosols are considered polar or hydrophilic (water loving). The hydrophilic components can include alcohols, aldehydes, ketones, phenols and acids2.
Depending on how much water versus the plant material (and how fresh it is) the distiller uses to obtain hydrosol, the end result can be a very divine and lively product with a wonderful aroma.
If too much water is used, the aroma will not be as strong and the amount of volatiles will be greatly decreased leaving a very diluted hydrosol.
Similar to hydrosols obtained with excess water, byproducts of essential oil distillations will be very diluted and not as effective. It is important to also know if the hydrosols are cohobated.
Cohobated hydrosols are those that have been recycled or redistilled through plant material to gain more volatiles for the purpose of creating essential oils. These type of products tend to be very weak and hold very little value, let alone quality.
It is also worthwhile to mention that the amount of plant material needed to create/obtain a high quality hydrosol is not nearly as high as what is needed to obtain essential oils. As little as about 3 pounds of plant material can create approximately 64 ounces of hydrosol depending on the type of plant and part of plant used. When we look at obtaining essential oils like Lavender for example, it might take about 150 kilograms of the lavender buds/stalks to obtain a single kilogram of the essential oil. Let that sink in for a moment.
If you are looking for hydrosols, make sure you ask if the hydrosols are those that are created to obtain hydrosols versus those that are obtained for the purpose of creating essential oils. As Jeanne Rose says, “Hydrosols are the real aromatherapy.” When properly crafted, the can truly “represent the true synergy of herbalism and aromatherapy.3”
1,2Harman, A. (2015). Harvest to Hydrosol. Fruitland, WA: IAG Botanics LLC dba botANNicals.
3Rose, J. (2001). 375 essential oils and hydrosols. Berkeley, CA: Frog.