Alan Geisler

Alan Stark Geisler (September 30, 1930 – January 6, 2009) was an American food chemist, best known for creating the red onion sauce most often used as a condiment topping on hot dogs in New York City. Specifically, the sauce, which is marketed as Sabrett's Prepared Onions, is usually served on Sabrett brand hot dogs sold by New York's many pushcart hot dog vendors.

As of 2009, Geisler's red onion sauce enjoys "a couple of million dollars a year in sales," according to Papalexis. Geisler's and Papalexis's original company, Tremont Foods, is currently a division of Marathon Enterprises, Inc., which owns the Sabrett trademark. (Marathon Enterprises is owned by Papalexis. ) The only product made by Tremont Foods is the popular red onion sauce. The sauce is manufactured in The Bronx, but production is scheduled to shift to a new facility, in Fair Lawn, New Jersey, in 2009.

Geisler remained active with the company until his death in 2009.

Death Geisler died at his winter home in Hernando, Florida, on January 6, 2009, at the age of 78. Geisler had been suffering from a protein disorder called amyloidosis. He was survived by his wife, Jean Geisler, his daughter, Martha Geisler, his son, Glenn Geisler, his brother and a grandson.