Hydrosols

A hydrosol is the aromatic water collected during botanical distillation. As vapor from the still cools, water condenses and carries a portion of the plant’s volatile chemistry.

Hydrosols bring botanical aroma into a water-based preparation, with a composition and character of their own.

What is in the water?

Some aromatic constituents have enough affinity for water to remain dissolved in the distillate. Others favor the separate essential-oil phase.

Hydrosols often contain a different balance of aromatic compounds from the corresponding essential oil. More water-compatible constituents, including certain aromatic alcohols and other oxygen-containing compounds, can make a substantial contribution to their profiles.[1]

This helps explain why a hydrosol can smell noticeably different from its essential oil. It is a distinct expression of the distilled material.

Hydrosol, tea and aromatic mist

A tea is made by steeping plant material directly in water. A hydrosol is collected from condensed vapor. An aromatic mist may instead be assembled by combining water with fragrance materials and other ingredients.

“Hydrosol” describes an ingredient and its production. “Toner” describes a product’s role in a skincare routine. A hydrosol may be used at that step, while a toner can contain a wider range of ingredients.[2,3,4]

A co-distilled example

Our Dreamy Mugwort & Lavender Hydrosol has a sweet, herbaceous aroma and can be used as a facial mist, body mist or aromatic linen spray.

The mugwort and lavender go into the still together. This is called co-distillation, distinguishing it from blending two separately distilled hydrosols.[5]

Related entries: Distillation; Essential oils; Preservation & shelf life; Hydration & moisturizing.