Hay notes in perfume can be created with hay absolute, clover absolute, tonka bean absolute, or other coumarin-rich natural extracts, as well as from natural or synthetic coumarin isolate. Natural hay extract smells as you might imagine, with sweet herbaceous notes and undertones that are fruity and often tinged with a little bit of tobacco. Hay is useful in amber and chypre accords, as well as in perfumes with an outdoorsy theme.

A bale of rolled hay in Montana (from Wiki) is shown.