Back before grocery stores and fancy cake recipes, if you wanted to make your bread rise, you needed leavening agents from natural sources.

回到杂货店和精美蛋糕食谱之前，如果你想让你的面包发起来， 你需要天然来源的发酵剂。

So bakers started using chemical leavening agents like baking soda, which, if we were to use the actual chemical name, we would just call it sodium bicarbonate.

因此，面包师开始使用小苏打等化学发酵剂，如果我们要使用实际的化学名称， 我们会称之为碳酸氢钠。