Zesto was started by entrepreneur and inventor L.A.M. Phelan as a national franchise. Phelan was head of the Taylor Freezer Corporation, which in 1945 had developed the "Zest-O-Mat" frozen custard machine, and franchise agreements granted exclusive use of the Zest-O-Mat machines in a given territory under the Zesto name. The first known Zesto Drive-In was opened in Jefferson City, Missouri in 1949 with dozens more opening throughout the 1950s, mostly in the U.S. South and Midwest. Taylor Freezer Corp, reportedly growing frustrated with managing a retail business and dealing with franchisees, abandoned the Zesto concept in 1955 and left the remaining franchisees to fend for themselves.