In the 1870s, Walter B. Duffy inherited a cider refining business from his father, Edward, who had begun business in Rochester about 1842. 

In 1881 the Rochester Directory lists Duffy as a Distiller & Rectifier of Alcohol, French Spirits, Malt, wheat, Rye and Bourbon whiskies.  at 27 & 29 Lake Ave.

It was in 1886 that the company first boasted of itself as producer of the "Celebrated Duffy's Malt Whiskey", which it advertised as the "greatest known heart tonic."

DUFFYS MEDICINE SPOON / SHOTGLASS

READS " A MEDICINE" IN THE CENTER BOSS

Duffy's claim, in an era of temperance movements was that "Malt" meant medicinal.  

Indeed at the time alcohol was a widely used additive to bitters and other medicines.  

Duffy's was classified as a medicine and sold in both bars and in drugstores before the turn of the century.

In 1906, Samuel Hopkins Adams wrote an expose of the patent medicine industry for Colliers magazine.

Samuel Hopkins Adams (January 26, 1871 – November 15, 1958) was an American writer, best known for his investigative journalism.

Adams was born in Dunkirk, New York. In 1891, he graduated from Hamilton College.

From 1891 to 1900, he was a reporter for the New York Sun and then joined McClure's Magazine, where he gained a reputation as a muckraker for his articles on the conditions of public health in the United States.

In a series of eleven articles he wrote for Collier's Weekly in 1905, "The Great American Fraud", Adams exposed many of the false claims made about patent medicines, pointing out that in some cases these medicines were damaging the health of the people using them. The series had a huge impact and lead to the passage of the 1906 Pure Food and Drug Act.

Duffys' was one of the targets of Adams' attack.

In 1911 the Supreme Court ruled that the prohibition of falsifications referred only to the ingredients of the medicine. This meant that companies were again free to make false claims about their products. Adams returned to the attack and another series of articles in Collier's Weekly, Adams exposed the misleading advertising that companies were using to sell their products.

Listings for The Duffy Malt Whiskey Company can be found up to 1926 although it is believed that it never reappeared after prohibition was lifted.