Buttermilk

Buttermilk is a chef's secret weapon for making fluffy pancakes and baked goodies. But how does this enigmatic liquid stack up against its creamy cousin? According to Southern Living, buttermilk is a byproduct of the butter-making process. When the fat begins to coagulate in the vat's center, the liquid that separates is allowed to grow with naturally occurring bacteria and yeast before being bottled and kept as buttermilk.

Although buttermilk is significantly thinner than Greek yogurt, the two have some tanginess in common. Buttermilk should be substituted for Greek yogurt in recipes with caution and changes to other liquid ingredients to guarantee the right moisture in the batter or dough. Because the buttermilk's thinness does not give the fattiness and texture required for a yogurt sauce or dip, you should make tzatziki using other types of dairy products.