Is buttermilk meant to smell and taste sour?

Yes, buttermilk is meant to have a sour taste and smell due to the presence of lactic acid produced during fermentation. This sourness is a key characteristic that distinguishes buttermilk from regular milk. The tangy flavor enhances its use in various recipes, such as pancakes and dressings. However, it should not have an off or rancid smell, which could indicate spoilage.