This is something I had never even considered or heard of before, but recently I was told that because Calgary has an altitude of just over 1000 metres this affects ingredients when baking. This (I think!) therefore explains my not so great attempts at making sponge cakes here – in the UK I could easily rely on making a quick and successful sponge cake if needed.
My few attempts here have been rather flat and had huge bubbles appear on the surface, and one was very dry. I put this down to a) not having a big enough cake tin for one recipe! B) using cup measurements which I don’t think are as accurate as grams and c) getting used to different ingredients, e.g. The types of flour etc.
However, I have since looked online and found that the low air pressure above 1000 metres makes baked foods rise more quickly and lose moisture as water evaporates more quickly, therefore adjustments need to be made: adding more liquid, removing some sugar, decreasing amounts of baking powder.
As I only thought of looking into this part way through making my cake, I only had time to add more liquid, and so added an additional egg. The large bubbles on the surface of the cake suggest I need to remove some sugar next time. It is quite flat still so will need to investigate that further. It also cooked quicker than expected so is quite golden on top! I can testify though that it still tastes good!
If you are interested in looking into this further, check out this website Science of cooking