The induced freezing of drops of supercooled water covered by uncompressed monolayers of the aliphatic alcohols C n H 2n+1 OH, n=16-31 was investigated. The ice-nucleation temperatures were found to depend on the length of the hydrocarbon chain and the parity of the number of carbon atoms in the chain. A gradual increase of the freezing point from -14 o C leveling off to a plateau at -7.5 o C from n=22 onward was observed for the even series. Alcohols with n odd raised the freezing temperature from -11 to -1 o C for n=17-31. Fatty acids (C n H 2n+1 COOH) or alcohols bearing a fluorocarbon chain or a steroidal backbone as the hydrophobic part induced nucleation of ice at much lower temperatures