Baking Powder contains Sodium Bicarbonate, but it includes the acidifying agent already (such as alum or SAPP), and also a drying agent (usually starch). Baking Powder is available as single-acting Baking Powder and as double-acting Baking Powder. Single-acting powders are activated by moisture, so you must bake recipes which include this product immediately after mixing. Double-acting powders react in two phases and can stand for a while before baking. With double-acting powder, some gas is released at room temperature when the powder is added to dough, but the majority of the gas is released after the temperature of the dough increases in the oven.
Baking soda is pure Sodium Bicarbonate. When baking soda is combined with moisture and an acidic ingredient (e.g., yogurt, chocolate, buttermilk, honey), the resulting chemical reaction produces bubbles of carbon dioxide that expand under oven temperatures, causing baked goods to expand or rise.
The reaction begins immediately upon mixing the ingredients, so you need to bake recipes which call for baking soda immediately, or else they will fall!
So baking soda is not stable, baking soda will appear sour, affecting the taste
But Baking Powder it can make the bakery food products stable, having soft internal structure, small uniform holes, and delicate taste.
As a China Baking Powder manufacturer-Bailin Group Co. we can provide Baking Powder and baking soda with competitive price.