Coumarin

Definition

Coumarin occurs in sweet clover, woodruff, tonka bean and many grasses, and is what makes drying hay smell as it does. It carries into sweet clover honey as a soft sweet-hay and vanilla warmth, which is what separates it from ordinary clover honey.

Where the word gets used loosely

Coumarin is harmless in honey and genuinely dangerous in spoiled sweet clover hay, where moulds convert it to dicoumarol, a potent anticoagulant. Cattle bleeding to death after eating mouldy melilot is how warfarin was discovered. The fresh plant and the honey are unaffected.

Honey records that discuss this

• Sweet clover honeyWarm, sweet and hay-like with a soft vanilla note that is genuinely there rather than imagined — the clearest coumarin character of any common honey.

Plant records that discuss this

• Sweet cloverVery high nectar over a long dry-season window, and shallow enough florets that honey bees can work it properly — which alfalfa, growing in the same fields, will not allow.