My mother made this stuff about once a week with all the week's leftover bread. She never threw out a crust. But while the site is correct about using wheaten bread instead of the more common corn and rye bread the Colonists usually ate, they are wrong about the domestically produced colonial wheaten flour being exported to Britain. Yes, wheat flour was a cash crop for the colonists of the Middle Colonies and produced for foreign trade, but not to England. Most Colonial flour went to the West Indies or Southern Europe. Not only did Britain grow their own wheat but they protected it as well. The Corn Laws (corn in British English means any grain, not solely American maize) forbade its importation from outside the British Isles until all of the grain produced in England had been sold thus subsidizing the domestic grain crop. Only in bad crop years was it likely to happen that England would want foreign grain and by the time the news reached America our grain was already committed elsewhere and could not be gotten to England in a timely manner. It is interesting that Britain repealed the Corn Laws in the 1840's and the US then started marketing it there. As a matter of fact this may have been one of the influences on Britain to stay neutral in the coming American Civil War as this now important American grain crop would obviously dry up if Britain and the US went to war. By the way,
the wife and I are aficionados of bread pudding and we like to stop at roadside diners where, at least in NJ, they still use left over bread to make bread pudding ( and diners in NJ are more common than pine trees, oil refineries and state troopers on the turnpike).