The title is said twice by Koenig when referring to Simmons' chemistry know-how and by Enoch when referring to his knowledge in drink mixing.
Freddy said his father lost money in the stock market crash. On October 29, 1929, the stock market crashed more than 75 points. The Great Depression initially started in September 1929 and went on until 1939. The crash was followed by bank failures, agricultural over-production, and drought.
Koenig says "Hydra? Red Skull? Super soldier serum? Sounds like something out of the funny papers." Funny papers was the nickname for the comics section of a newspaper, and Hydra, Red Skull and super soldier serum were all originally part of Marvel comics.
"Know Your Onions" originally aired on ABC on June 3, 2020 and was watched by 1.50 million viewers.