Born in Brooklyn, the young Tillie met Italian importer Florindo Del Gaizo when she was a Broadway chorus girl, and became his mistress and business associate. When the federal government raised the tariff on imported tomato products by 50%, the pair decided to grow Italian tomatoes in California, and they combined parts of their first names to create Flotill Products Inc. They opened their first tomato cannery in Stockton, California in 1937. Two years later, when del Gaizo died, Lewis bought out his share of the business. Operating the first cannery owned by a woman, in the 1940s, she started canning other fruits and vegetables, baby food, frozen juices. During the Second World War, the company also became the largest producer of C-rations for the U.S. Army. By 1951, Flotill Products, later known as Tillie Lewis Foods, Inc., was earning 30 million dollars per year, making it one of the five largest canning companies in the United States. In the same year, Lewis was named "businesswoman of the year" by the Associated Press. In 1952, the company introduced a line of diet foods using low-calorie sweeteners and known as Tasti-Diet. Tillie Lewis Foods was eventually bought by the Ogden Corporation, which made Lewis one of its directors until she died in 1977.