The bitterness is all

Well, this is interesting. Since I came to the States, I've been detecting a bitter aftertaste in anything I've raised with baking powder. As I didn't notice it in the UK and I don't believe I've suddenly developed a more sensitive palate, I am wondering whether (a) this is a matter of quantity (US recipes frequently call for more baking powder than I would have expected in the UK); or (b) the alumin(i)um question (I have no idea whether my UK baking powder did or didn't contain alumin(i)um; our current US variety - Clabber Girl - certainly does); or (c) some other difference or distinction that I have not yet run to earth (there is - inevitably - a difference of opinion on the internets, as to whether there is or isn't any significant difference between UK and US baking powders). Whatever: something is going on here, and I would quite like to figure it out. Poor Karen may be faced with a constant succession of buns and cakes and questions...