At his new blog, Splendid Isolation, Kim du Toit explains the historical roots of a French culinary oddity:
One of the quirks of French cuisine is that most often the butter is unsalted, and at a French dinner table you will usually find a tiny cruet of salt with a microscopic spoon inside, so that you can salt your butter (or not) according to taste. To someone like myself, accustomed only to salted butter, this seemed like an affectation, but it wasn’t that at all: it was the result of taxation, and this is one of the things changed forever by Napoleon’s administrative reforms.
One of the best parts of our U.S. Constitution is the “interstate commerce” clause, which forbids states from levying taxes on goods and services passing from one state to another, and through another in transit. This was not the case in pre-Napoleonic France. Goods manufactured in, say, Gascony or Provence would pass through a series of customs posts en route to Paris, and at each point the various localities would levy excise taxes on the goods, driving up the final price at its eventual destination.
Which brings us to salt. French salt, you see, was produced mainly on the Atlantic coastline, and was a major “export” of Brittany to the rest of France. Butter, of course, was produced universally — in and outside Paris and ditto for every major city — but the salt for the butter came almost exclusively from Brittany, and having been taxed multiple times by the time it reached points east like Paris or Lyons, it was expensive. So the cuisine and eating habits in those parts developed without the use of salt — or, if salt was requested, at an added cost. It’s why, to this day, many French recipes use unsalted butter as an ingredient. (In contrast, butter for local consumption in western France was [and still is] almost always salted, because salt was dirt cheap there.)
Napoleon’s reforms did away with all that; he saw to it that the douane locale checkpoints and toll booths along the main roads were abolished (causing salt prices in eastern France to plummet and become a mainstay of French cuisine at last). And when the towns and villages protested about the loss of tax revenue, Napoleon made up the shortfall with “federal” funds out of the national treasury.
Of course, the French treasury had in the meantime been emptied out by, amongst other things, the statist welfare policies of the Revolutionary government (stop me if this is starting to sound familiar). Which is why, to raise money, Napoleon invaded wealthy northern Italy and western Germany (as it is now), pillaged their rich cities’ treasuries and garnered revenue from the wealthy aristocracy, who paid bribes to avoid having their palaces sacked and their wealth confiscated.