MASLENICA (Croatia) - A SLOVENIAN winemaker on Friday revealed his unique technique for maturing wine when he retrieved 600 bottles that he laid six months ago in clay-made amphorae on the Adriatic seabed.The sparkling wine, named Poseidon after the Greek god of the sea, was placed at a depth of 30m where the temperature is between 12 and 13 deg C, perfect for storing and maturing wine, Ivan Simonic told AFP.The constant movement of the sea means the usual techniques used to mature sparkling wine are not necessary, he added.