TDN (riesling petrol note)

TDN, or 1,1,6-trimethyl-1,2-dihydronaphthalene, is the compound behind the petrol note characteristic of ageing Rieslings. Its detection threshold sits near four micrograms per litre, with recognition arising around ten to twelve. In small amounts it enriches the bouquet with complexity; beyond roughly thirty micrograms, the kerosene odour dominates and masks the fruit. Its formation is favoured by strong sunlight on the vine and by extended bottle age.