What is the idiomatic expression for has flavor of rotten

The most common idiomatic expression for something that has the flavor of rotten is "tastes like rotten eggs". This is a very direct and descriptive way to convey that something has an unpleasant, sulfurous flavor.

Here are some other options, depending on the specific type of rotten flavor you're trying to describe:

* "Tastes like garbage" - This is a more general expression for something unpleasant and unappetizing.

* "Tastes like spoiled milk" - This expression conveys a sour or acidic taste.

* "Tastes like death" - This expression is very strong and suggests a truly foul and inedible flavor.

Ultimately, the best expression to use will depend on the specific context and the level of intensity you want to convey.