Mugwort

Bitter and green-herbal, with a cool camphoraceous edge and a dry, slightly hay-like finish.

• Before hops took over, mugwort was one of the herbs used to flavour and preserve beer; sixteenth-century herbals still advised hanging it in the barrel to keep the brew from turning sour.

The oil varies so much by origin that researchers speak of distinct chemotypes: one sample grown in Brazil was about 37 % caryophyllene, while a population from Dagestan yielded roughly 28 % trans-chrysanthenyl acetate.