Here are a few reasons why you should always have a carton of buttermilk in your fridge:.Buttermilk contains lactic acid, which produces bacteria that gives a tangy flavor and complexity to baked goods. .The acid in buttermilk also activates baking soda, which lightens the dough or batter you are mixing. .According to food scientist Harold McGhee, buttermilk can keep baked goods from browning too quickly.When it comes to fried chicken, a buttermilk brine can take theiconic dish to new heights.Buttermilk adds an extra tang, and, thanks to its acidic nature, it acts as a tenderizer for the meat.Buttermilk is also magic in ice cream. It adds a tangy taste that is perfect paired with fruit cobblers.Here's one last magic trick with buttermilk: drinking a glass can help sooth an upset stomach