Episode 20: A Great Molasses Flood Swept Through Boston in 1919

Slow as molasses in January is a common American idiom for something that is painfully slow. The history of this expression dates to the turn of the twentieth century and to one very specific event. On an unseasonably warm winter day in 1919, only a few weeks into the new year, Boston, Massachusetts suffered one of history’s strangest disasters. Have you ever heard of the Great Boston Molasses Flood?



For this episode, I had the pleasure of speaking with Stephen Puleo, historian, public speaker, and author of Dark Tide, and Nicole Sharp, an aerospace engineer turned science communicator who runs a Tumblr blog on fluid dynamics.


Dark Tide: The Great Boston Molasses Flood of 1919; Puleo, Stephen; Beacon Press; 2004; Reprinted 100th Anniversary Edition, January 2019.

Incredible physics behind the deadly 1919 Boston Molasses Flood; Ouellette, Jennifer; NewScientist; November 24, 2016.

The Great Molasses Flood of 1919; Andrews, Evan; History; January 13, 2017.

The Great Molasses Flood; Stanly, Robert; New England Today; January 15, 2018.

Remembering Boston’s Great Molasses Flood of 1919; Trex, Ethan; Mental Floss; January 15, 2018.

Eric Postpischil’s Molasses Disaster Pages; Mason, John; Yankee Magazine; August 27, 2015.

Great Molasses Flood of 1919: Why This Deluge of Goo Was So Deadly; Choi, Charles; LiveScience; November 21, 2016.