A new kettle of fish dating
'A different kettle of fish' is much later in origin than 'a pretty kettle of fish' and is known only since the 1920s.
It's quite pleasing that, as far as etymology goes, 'a different kettle of fish' is a different kettle of fish.
a fire is kindled, and live salmon thrown into boiling kettles”. The latter means “a situation that is completely different from a previous one”, whilst the former means “to be completely different from something or someone else that has been talked about”. Set a Fish-Kettle on the Fire, with Water enough to boil it, a good Handful of Salt, a Pint of Vinegar, a Bundle of sweet Herbs, and a piece of Horse-raddish; let it boil a Quarter of an Hour, then put in the Head, and when you are sure it is enough, lift up the Fish-Plate with the Fish on it, set it across the Kettle to drain, then lay it in your Dish and lay the Liver on one side.
Garnish with Lemon and Horse-raddish scraped; melt some butter, with a little of the Fish Liquor, and Anchovy, Oysters, or Shrimps, or just what you fancy.
As Peter Shor's comment beneath Ralph Richardson's answer indicates, "kettle of fish" has been used as a slang term for several centuries.
The same definition of the term that he points to appears in Francis Grose, . I doubt [that is, fear] we have but rouz'd a sleeping Lion : A stop-Thief has sometimes saved a House-breaker ; and many a Wench has sav'd her Reputation by crying Whore first : But the more this Matter is stirred, the more it stinks, and I doubt we have made a fine Kettle of Fish on't.
This pretend dialogue is unusual for the multitude of proverbs and idiomatic phrases that the two knavish masons pitch back and forth in this part of the dialogue—"a Fool's bolt is soon shot," "When Knaves fall out, Honest Men come by their Rights," "a Word to the Wise," "Penny wise and Pound foolish," "putting a Spoke in my Wheel"—but as testimony taken at a trial for adultery adjudicated on December 5, 1738, suggests, "a fine kettle of fish" may not yet have been broadly familiar to English people.
From 'There you have done a fine Piece of Work truly.
The expression dates from the late 19th century and was found most commonly in Scotland and the north of England (where fish kettles were and still are quite commonplace).From Oliver Optic, "I had almost forgot to mention that brother Joseph had arrived in New York, and telegraphs that he shall be here to-night by the New Haven train." "Just like you! "That everlasting niece of yours is in the way again." "A southerly wind and a cloudy sky" may be a very pleasant theme for fox-hunting squires in dear Old England, but when a man is under a cloud in a foreign country, with a southerly wind in his pockets, and Mary Thompson's mark, " M.T." on his clothes chest, then it's quite another kettle of fish. The faithful minister, we are told, may always rely on adequate and generous support, and if at any time, ...Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Visit Stack Exchange English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. Sign up to join this community There was, it seems, a custom by which the gentry on the Scottish border with England would hold a picnic by a river.The custom was described by Thomas Newte in his Tour of England and Scotland in 1785: “It is customary for the gentlemen who live near the Tweed to entertain their neighbours and friends with a Fete Champetre, which they call giving ‘a kettle of fish’.