Curd can be used as an alternative to yeast in certain recipes; however, it is important to note that curd does not have the same properties as yeast. Curd does not contain any active ingredients like yeast does, so it cannot cause bread or dough to rise in the same way. On the other hand, curd can add a unique flavor and texture to recipes that call for it. Curd typically contains lactic acid bacteria, which produces lactic acid when fermenting, and this can contribute to a light and tangy flavor while also helping with preserving food. In most cases, it is best used as a complementing ingredient rather than as an outright replacement for yeast.