What yarrow does to soap

I get this question more than any other. Yarrow (Achillea millefolium) is a small white-flowered herb that grows along most trails in the Sangre de Cristos. People use it for cuts. There's a long folk medicine tradition of pressing the leaves to a wound to stop bleeding. The active compound is called achilleine.

In soap, yarrow does something specific: it makes the bar harder. The infusion strengthens the saponified fats, which means the bar lasts longer and lathers slower. It also adds a faint hay-like scent that I love but that some customers find too herbal.

That's it. There's no 'cleansing energy' or 'protective property' to yarrow soap. It just makes the bar tougher and smells like the trail. The Yarrow & Tallow soap is the one I personally use; it lasts me about ten weeks per bar.

Linden, September 2025.