Cut the mustard
To cut the mustard is American in origin and means to succeed or conform to the required standard, but is most often used in the negative form can’t cut the mustard meaning incompetence, failure or not able to compete, sometimes with a sexual connotation. The expression dates from the late 19th/early 20th century and derives from earlier American slang where the mustard meant the genuine article or the real thing based on the notion that mustard enhanced flavour. Cut is used in the sense of achieve, hence, if you couldn’t cut the mustard you were a failure in that you could not achieve the required standard because you were not the genuine article. Today, the complete expression is rarely used and has been replaced by the abbreviated forms of can’t cut it or can’t hack it. See also Keen as mustard.