I noticed that the “original recipe” Bisquick in my mother's fridge a) contains sugar, b) does not list hydrogenated oils, and c) does not say to keep refrigerated. This is not consistent with our collective memories. I did some googling and found some information on various changes over time, such as replacing lard with hydrogenated oils, but nothing like a definitive timeline, and no reliable-looking sources or citations.
I am also aware that there have been other Bisquick products, such as a “Heart Smart” version with no trans fats, but I'm mostly interested in how the composition of the “original”-branded version has changed.
Does anyone know of any authoritative sources on this?