Acescent is an adjective that means turning sour. 

Our word of the day comes from the Latin word acescere (ah che SHARE ay) which means ’to become sour.’ Its earliest use in English can be traced back to the mid-17th century. In addition to being implemented to describe food or beverage, acescent may also be used to describe a mood or atmosphere. Here’s an example:

I got the sense that people at the dinner party didn’t like my cooking. No one said this in so many words, but every time the subject of my fried turkey sandwiches came up, the mood in the room turned sour. That kind of acescent atmosphere is usually a red flag.