Baking Powder

 

Baking powder should be GF as it’s sodium bicarbonate. It has a chemical formula of NaHCO3.

I used to work for Mond Division of ICI and they had two Solvay processes that produced tons of the stuff. One was built about 1880 out of oak beams instead of steel girders. If you were over five foot six you kept bumping your head, as people were smaller then.

However, someone might stick some additive in it. I suspect you can buy pure sodium bicarbonate in a pharmacy with a BP label on it.

I just phoned my local Boots in Newmarket.

They stock 500 grams or half a kilo of pure sodium bicarbonate, which costs £1.89. That should be enough to last you a lifetime if you keep it dry!