It has been percolating since the union of the crowns in 1603. It heated up rapidly in the Lowlands, Highlands, and islands over the past decade.
It reached a full rolling boil last spring, when it helped dissolve the previous Labour government in Britain.
Now it may be as cold as yesterday's porridge oats.
The issue: home rule for Scotland, or "devolution." Barely a year after narrowly defeating the Scotland Act referendum, the mood of the country seems to have shifted. It now appears that the present government, having proved in Rhodesia that devolution is possible (and in Northern Ireland that it may not be) may well be spared another challenge from the north.
But there are still plenty of political cooks fussing about, trying to revive the public's taste for this Scotch broth:
* The Scottish Labour Party, at its annual conference March 7 in Perth, overwhelmingly approved a resolution calling for a Scottish assembly "with meaningful powers over the economy of Scotland." While vague, the resolution sets a significant new direction: the Scotland Act included only legislative powers, not fiscal ones.
* An all-party rally here on the first anniversary of the referendum found individuals from the Labour, Conservative, Liberal, Scottish Nationalist, and Communist parties sharing the stage and agreeing to hold a convention in a year's time on the topic.
* The executive council of the Scottish National Party (SNP), which lost nine of its 11 seats at Westminster in last May's general election, resolved march 1 to continue to remind Scots that both major parties could offer only "betrayal, lies, and deceit" on the subject of independence for Scotland.
But despite the attention paid to these ventures in a vigorous and respected local press, many here concede that devolution, as one Conservative Party official put it, "is not a talking point" any longer.
Conservations with non-politicians here, as well as in Glasgow and Aberdeen, suggest that the heat has largely dissipated. One salesman who daily travels the borders area south of Edinburgh told this correspondent that he heard little about devolution any more -- from the same farmers who last year talked about it everywhere.
The business community, too, realizing that 50 percent of Scotland's business is with the rest of Britain, is also breathing more easily now.
The main fuel for devolutionists is North Sea oil. Most of it lies on Scotland's side of the border. Control of it could make Scotland, as one observer noted, "almost Saudi Arabia" in wealth per head.
And Scotland, unlike England, also has ample farmland -- nearly enough for agricultural self-sufficiency. Many Scots are said to have voted "no" last year because the referendum offered them too little economic control over what they feel is rightfully theirs.
The situation in Wales is often brought up for comparison. Welsh devolution was roundly defeated in a referendum on the same day last spring. There, too, the current reinterest appears to come largely from politicians.
But the Welsh were being offered an assembly with powers even more limited than those offered Scotland. "We were being given a rotten apple," said David Miller, general secretary of the traditionally home-rule-minded Scottish Liberal Party. "But they were being given a rotten prune."
But Wales, with a separate language spoken by some 20 percent of the population (few Scots, by contrast, speak Gaelic), has developed its own brand of nationalism. The Welsh Labour Party has called for another referendum. Plaid Cymru, the Welsh Nationalist Party, is promoting a campaign of withholding household television license fees in protest over what they see as the government's broken promise to provide Welsh-language service on the new fourth television channel.
More serious, however, is the "English go home" terrorism campaign. Since Dec. 13, ultra-nationalist arsonists have attacked 26 homes in Wales, principally those owned by English people and used as holiday homes.
The Scots, by contrast, are "a quiet, acquiescent people," says SNP spokesman Duncan McLaren. Mr. Miller agrees: Since the 1950s, he says, nationalist violence here has destroyed only one electricity pylon and eight post boxes. But he worries that the present situation may be "dangerously quiet."
The Conservative Party official, however, while agreeing that "devolution as such will never be dead," feels that a local assembly "would not make a scrap of difference" in the present difficulties. Steadily climbing unemployment, increased emigration, and general economic gloom can only be overcome, he feels, by working in concert with the rest of the country to improve the overall outlook.