Bicarb of Soda - one for the Consultants among us

Hiya,

Can any of you, especially the Consultant members who have access to the dark knowledge of SW, answer me this: Why is Bicarbonate of Soda synned (0.5 per tsp) when it is zero calories (Google it) and pure chemical compound? Baking powder fair enough as it is bulked out with flour. But why bicarb?

Thanks!

If you enter the nutritional info into the calculator (0 kcal, 0 carbs, 0 protein 0 fat) then surprise of surprises it comes out free! Who'd have thought?