Our friends on the western side of the Atlantic are divided from us not only
by a lot of water, and a common language but also a common system of weights
and measures that has lost a little in the translation. The difficulty
Americans experience in dissolving X pounds of sugar in Y gallons of water
according to the recipe is caused by your gallons being smaller. English
capacity measures are 20 fluid ounces to a pint (not your 16) and 8pints to a
gallon. Somebody who is better at maths than I am will be able to tell us
what the adjusted recipe should be.
Chris Slade