The seeds do not have a scent but they become slowly aromatic when chewed and have a biting heat. The heat develops in liquid. Brown mustard tastes mildly bitter and is the hottest, with white mustard being somewhat less hot. When mustard seeds are fried they gain a slightly nutty and aromatic flavour but do not become hotter. Mustard contains around one third fatty oil, which is used for frying and flavouring in India.