Aromatically, I prefer the aroma of Yarrow Essential Oil to that of Yarrow Hydrosol. Like the essential oil, it is woody and herbaceous, but I find that it is much sharper in aroma.
Up to 2 years if stored properly (refrigeration is recommended).
Reported Properties, Uses and Applications
Len and Shirley Price report that the Yarrow Hydrosol that they analyzed consists of a ratio of 50-64% eucalyptol, 10-19% alcohols, 17-19% aldehydes, 7-13% ketones (these ranges do not include the water present in the hydrosol) and possesses the following properties: "analgesic, anticoagulant, anti-infectious, anti-inflammatory, antiviral, bactericidal, calming, cicatrizant, circulatory (hypotensor), decongestant, digestive, expectorant, febrifuge, lipolytic, mucolytic, sedative, stimulating, tonic." [Len Price and Shirley Price, Understanding Hydrolats: The Specific Hydrosols for Aromatherapy: A Guide for Health Professionals (London: Churchill Livingstone, 2004), 95.]
Jeanne Rose adds that Yarrow Hydrosol is useful for acne, damaged skin, cellulite, spiritual healing and for auric work. [Jeanne Rose, 375 Essential Oils and Hydrosols (Berkeley, CA: Frog, Ltd, 1999), 171.]
Read AromaWeb's Hydrosol Safety Guidelines.