Q: Where did the phrase “can’t cut the mustard” come from? It doesn’t seem to make any sense to me.
A: The phrase “cut the mustard” originated in the United States about 100 years ago. It was first recorded in an O. Henry story published in 1902. It means “to succeed” or “to work” or “to be able to accomplish something.” But why “mustard”? Nobody seems to know for sure. One theory is that it may be associated with the military word “muster,” meaning to gather troops for inspection. If you “pass muster,” you pass inspection. Then why “cut”? Again, one can only speculate.
The word expert Michael Quinion has this to say (from his Web site World Wide Words): “It’s much more likely that it’s a development of the long-established use of mustard as a superlative, as in phrases such as keen as mustard. In the nineteenth century in America, mustard was used figuratively to mean something that added zest to a situation, and the proper mustard was something that was the genuine article.”
Hope this helps. As with many old expressions, we can’t definitively pin down the derivation of this one.