3 Answers

Yeast if you are making bread or baking powder for everything else Ammonium carbonate also known as bakers ammonia is used in scandinavian countrys and produces a more airy and light texure than baking powder and baking soda icelandic air biscuits known as loftkokur cannot be made with anything other than AC

Baking soda is tough to turn away from in cooking breads. I have been trying to get products that do that occasionally for years. There are several possible products that do not require sodium to achieve similar results. Tapioca flour has some promise for substituting in cookies. The baked result have been crunchy generally…I need to play with that more. I would like to try baking breads in a pressure controlled oven. By not using soda the bread would have to rise by reducing the oven pressure as it cooks similarly to the gas release of Baking soda so that air pockets expand in the hot dough. Releasing moisture while maintaining the form looks like an ingredient problem which is not necessarily a part of the use of soda. In yeast bread rising is augmented by BS but another factor is the alcohol that the yeast produces in converting carbohydrates and sugars. Alcohols boil off breads at around 198 degrees F. which is rather soon since the water wont boil off until 212F at normal pressure. Being able to adjust the atmospheric pressure and humidity of an oven would be a wonderful opportunity to try a lot of interesting combinations that in conventional cooking are impossible.    

There is no substitute.

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