What is the origin of the phrase "cut the mustard"?

Solution 1:

http://www.phrases.org.uk/meanings/cut-the-mustard.html

There has been an association between the heat and piquancy of mustard and the zest and energy of people's behaviour. This dates back to at least 1672, when the term 'as keen as mustard' is first recorded. 'Up to mustard' or just 'mustard' means up to standard in the same way as 'up to snuff'. 'Cutting' has also long been used to mean 'exhibiting', as in the phrase 'cutting a fine figure'. Unless some actual evidence is found for the other proposed explanations, the derivation of 'cutting the mustard' as an alternative way of saying 'exhibiting one's high standards' is by far the most likely.

Whatever the coinage, the phrase itself emerged in the USA towards the end of the 19th century. The earliest example in print that I've found is from The Iowa State Reporter, August 1897, in a piece about the rivalry between two Iowa towns:

Dubuque had the crowds, but Waterloo "Cut the Mustard"

The use of quotation marks and the lack of any explanation of the term in that citation imply that 'cut the mustard' was already known to Iowa readers and earlier printed examples may yet turn up.

Solution 2:

Found this early use of the phrase in a letter from "Rusticus" in The Railroad Trainman, a journal of The Brotherhood of Railroad Trainmen, 1898. In the letter, he reminisces with another letter writer about his days as a trainman which he says started in 1872. He puts in quotes all the slang words and phrases he remembers from those days, of which cut the mustard is one. This may indicate a railroad origin to the phrase. Here's a quote from his letter:

I can cheerfully shake "paws" with him, in my mind, and bring to mind the time when box-toed shoes, squaretopped silk caps and black jeans suits with an inch of braid all around, and spring-bottom pants, were all the "go;" and you could tell a "car-hand" as far as you could see him with the naked eye. And the "pison" he could punish with the "captain" was a caution. Then a "gafter" could buy a job for $10.00, and if he could not "cut the mustard" he was liable to "hit the grit" between stations. Oh, those rosy-hued days, when a brakeman was an important feature about the depot platform about the time the "varnished cars" came in; and what a masher he was.

Edit 6/29/11:

Just found an earlier use of cut the mustard that again seems to indicate a railroad lingo origin. This (see story to rt. of burglary report) is from The Weekly Californian, of Kern County, California, December 3, 1892. It is an account of an anniversary ball put on by the International Association of Machinists. Its use here clearly indicates the "railroad boys" met or exceeded the expected standard of appearance:

The railroad boys were enthusiastic over their apparent success. Each had attended with his best girl looking her prettiest, in fact the boys themselves “cut the mustard” with the Bakersfieldians. The charming costumes of the ladies lent a brightness to the scene, which with the good music did not fail to elicit the appreciation of all present.

Solution 3:

The first two quotations in the OED are both from the The Galveston Daily News (Texas, USA). First from 1891:

They applied several coats of carmine hue and cut the mustard over all their predecessors.

Second from 1892:

Time will reveal that he cannot ‘cut the mustard’.

Their definition 3c shows the reasoning and some variants:

slang (orig. U.S.). Something which adds piquancy or zest; that which sets the standard or is the best of anything. to cut the mustard and variants: to come up to expectations, to meet requirements, to succeed. to be (to) the mustard : to be exactly what is required; to be very good or special.

And in the early 20th century are examples like "they were not the proper mustard" and "he's all to the mustard".