γ-Valerolactone (FEMA # 3103, CAS 108-29-2) has a complex odor profile; one that defies easy description. It is quite possible to see some element of the hay-like character of γ-hexalactone within this odor mixture but the caramel character of γ-butyrolactone is definitely dominant. Behind these two warm notes there is also a distinct fruity aspect to the odor profile.
γ-Valerolactone is described in many different and contradictory ways in the literature and this is not surprising, given the odor complexity of the chemical. Several sources describe it as “herbaceous,” although the present author finds it difficult to make this connection.