Thanks guys, I very much appreciate your advice. Another problem I've got is that over here in England we don't seem to have the A,B,C grading system for maple syrup. ( Maybe it's possible to buy different grades in the big cities but certainly not here in the wilds of North Yorkshire). The only choice I've got is between brands and whether or not it's organic or not. I assume from your comments that I should go for the organic ones. On the labels the syrup is usually described as 'Class 1', 'pure Canadian Maple Syrup' and 'ideal for putting on pancakes" etc. I note in the book he says we can get away with using the more refined stuff but can I assume my fast will be less successful if I'm using it?