WASHINGTON — Peter J. Zwack, a Hungarian-born liquor magnate who helped safeguard the secret formula for his family’s prized Unicum digestif during years of Nazi and Soviet occupation and served a tempestuous stint in Washington as ambassador from Hungary in the 1990s, died Aug. 4 in Italy.
He was 85 and died, apparently of overexertion, while swimming at a hot springs spa near his home in the Tuscan town of Bolgheri, said his son Peter B.
Mr. Zwack cut an unusual figure in the diplomatic corps in Washington. The Washington Post once described him as ‘‘one of the most colorful among the ambassadors in Washington,’’ and later, after an unbecoming departure, ‘‘one of the most controversial.’’
A celebrity in his native country, Mr. Zwack had managed in the late 1980s to reclaim control of his family’s famed distillery — the producer of Unicum, an 84 proof bombshell sometimes called the Hungarian national shot — after four decades of Communist government ownership.
Western news media hailed him at the time as apparently the first businessman in the nationalized economies of Eastern Europe to achieve such a feat. There were calls in Hungary for him to run for president.
Beyond those distinctions, Mr. Zwack was a naturalized US citizen, and therefore an unlikely candidate for a foreign ambassadorship. He and his family had fled to the United States in 1948, after the government nationalized the distillery. They left behind a bogus recipe for Unicum, a concoction made from 40 herbs and roots that was created, according to family lore, in the late 1700s by a Zwack ancestor.
During Communist control in Hungary, the government-owned distillery produced a version of Unicum that was not quite right. Mr. Zwack’s father had tucked the real formula in a pocket when he escaped from Budapest to Vienna. Mr. Zwack later helped store the recipe in safety deposit boxes at four New York banks.
He had arrived at Ellis Island stripped of his considerable family wealth. He sold vacuum cleaners before finding work, first in New York and later in Chicago, in the wine-and-spirits import-export trade.
In 1971, he moved to Italy, where he joined a relative who had been producing small quantities of Unicum .
Then, in 1988, the reform-minded ‘‘goulash Communists’’ invited Mr. Zwack to return to Hungary. He agreed and, over time, reclaimed control of the distillery. Today it is known as Zwack Unicum, a publicly listed company owned by the Zwack family with partners.
‘‘People think I showed faith in Hungary when not too many others did,’’ he told The New York Times in 1989. ‘‘They had been fed this picture of a fat capitalist who smoked cigars and beat up the workers, and they saw me, a skinny guy who doesn’t smoke, wears beat-up clothes, and behaves more like the workers than the Communist bosses did.’’
As his country transitioned into democracy, Mr. Zwack was invited to serve as ambassador. He accepted and renounced, with some reluctance, his US citizenship.
In Washington, his first order of business was to discard the old brown curtains and repaint the embassy chancery that had become known as ‘‘the bunker.’’ In contrast with their Communist predecessors, he and his wife, the British writer Anne Marshall, became fixtures on the Washington social scene.
But after seven months, Mr. Zwack was removed from office. In an interview with The Post, Mr. Zwack attributed his removal to a conflict with his deputy chief of mission. The Post noted that neither Mr. Zwack nor his deputy had diplomatic experience.