Hello kyle_m. When checking milk without tasting, there are a few reliable methods you can use.
First, check the smell by pouring a small amount into a separate glass or sniffing directly from the carton after swirling gently. Sour milk produces a distinct, pungent, or sour odor due to lactic acid build-up.
Second, inspect the texture. If the milk appears lumpy, curdled, or separates into chunks when poured, it has spoiled and should be discarded. You can also perform a quick visual test by dropping a spoonful of milk into a cup of hot water; if it curdles immediately, it is bad.