Spanish or French? The double spelling hides an old dispute: is it a Menorcan sauce or a French invention? For centuries the romantic Duke of Richelieu story coexisted with the suspicion that France had claimed something that wasn’t its own. Today, research sides with Menorca — and brings the proof.
The short answer: mayonnaise was born in Menorca, where it was known as aioli bo. The long one features a French duke, a friar who cooked, a fake poem and a recipe book that changes everything. Here it is in full.
Where and when was mayonnaise invented?
Mayonnaise was born in Menorca and was already well known on the island, at the latest, in the first half of the 18th century — probably earlier. That cold emulsion of egg and oil was part of everyday Menorcan cooking long before the rest of Europe gave it a name.
It’s no accident it was born here. The island had a tradition of emulsified sauces related to Mediterranean aioli, and a taste for binding egg and oil that eventually set into a sauce of its own — fine and versatile.
The legend of the Duke of Richelieu (1756)
The most famous story begins in 1756. In the middle of the Seven Years’ War, France took Menorca from the British after the siege of Fort San Felipe, at the mouth of Mahón harbour. It was during that occupation that the French discovered the sauce.
Menorcan oral tradition, recorded by Lorenzo Lafuente Vanrell in the Revista de Menorca in 1914, tells that Richelieu tasted the sauce one night in a Mahón inn, was won over by that simple “egg sauce” and had the recipe written down, declaring it would henceforth be called “à la mahonnaise.” The writer Camilo José Cela even imagined a love letter from the duke giving the sauce its name.
Did the cook invent it, or did it already exist on the island?
For a long time people argued whether Richelieu’s cook invented the sauce or merely reproduced it. Modern research comes down firmly on the second: the sauce already existed in Menorca. The French didn’t discover it; they found it ready-made and spread it across Europe through their ever-present cuisine.
From “mahonnaise” to “mayonnaise”: where the name comes from
Once in France, the sauce became popular as mahonnaise — “the one from Mahón” — which then drifted to mayonnaise. French cuisine, however, spent years trying out alternative etymologies to erase that trail: the great Antonin Carême derived it from magonnaise (from manier, to handle); others tied it to the Mayenne region (which has no olive trees!), to the city of Bayonne (bayonnaise), or to Old French moyeu, “egg yolk.”
As Pep Pelfort sums up, these are convoluted explanations against the simplest and most obvious one: the name comes from Mahón.
The Menorcan proof: Fra Roger’s recipe book and the “aioli bo”
The best proof of the Menorcan origin lies not in a legend but in a book. The manuscript Art de la cuina, by the Menorcan friar Fra Francisco Roger (mid-18th century, published by the Institut Menorquí d’Estudis in 1993), records the sauce no fewer than 19 times. Not under its modern name, but as “aioli bo” — literally “good aioli.” In Menorcan, the adjective bo marked something finer and of higher quality, as in pebre bo (the pepper) or oli bo (good oil).
The most revealing part is how researcher Pep Pelfort, of the Centre d’Estudis Gastronòmics de Menorca, proved it: he cooked the recipes from the manuscript. Made with aioli (garlic), they turn out sour and barely edible; made with mayonnaise, they’re subtle and perfect. What’s more, Fra Roger repeatedly calls for “trempar” the sauce with lemon juice — a step that stabilises and whitens mayonnaise, as cook-chemist Hervé This has confirmed, but that makes no sense in an aioli. Fra Roger’s sauce was, without doubt, mayonnaise.
The French poem that turned out to be fake
The main argument for French authorship was a poem describing the recipe, attributed to a certain Lancelot and supposedly dated 1625, well before the conquest. If genuine, it would settle the debate. But it isn’t: after decades of searching begun by Cela and finished by José María Pisa, the poem was shown to be the work of Achille Ozanne, a 19th-century cook-poet. With that “witness” gone, the last argument against the Menorcan origin collapses.
Mayonnaise, mahonesa and aioli: are they the same?
Spain’s Royal Academy accepts both spellings for the same sauce. They mean exactly the same thing: a cold emulsion of egg and oil, seasoned with salt and a touch of lemon or vinegar. It’s technically a mother sauce, the base for many others.
Aioli is a close relative but not a twin: it contains garlic and, in its purest form, no egg. Mayonnaise drops the garlic and is built on an egg emulsion. What made it Menorcan wasn’t a secret recipe but centuries of homemade-sauce tradition.
Where to taste authentic mayonnaise in Menorca
In Menorca, mayonnaise is still a table sauce — homemade and everywhere. You’ll find it alongside fresh fish, seafood and iconic dishes such as the Fornells lobster stew.
To explore the island’s cuisine beyond the sauce, see our guide to Menorcan gastronomy, the Menorcan charcuterie and other products bearing the Mahón name, such as Mahón cheese.
Historical source: Pep Pelfort, “La verdadera historia de la salsa mahonesa, también llamada aioli bo” (Centre d’Estudis Gastronòmics de Menorca, 2013).
Is mayonnaise Spanish or French?
It’s Menorcan. Research shows the sauce already existed on the island — called “aioli bo” — in the first half of the 18th century, and that the French merely spread it across Europe after the 1756 conquest.
Why is it called mayonnaise if it was born in Mahón?
The original name was “mahonnaise,” after Mahón. As it became popular in France as “mayonnaise,” the spelling drifted. The alternative French etymologies have never held up.
What is “aioli bo”?
It’s the old Menorcan name for mayonnaise. It appears 19 times in Fra Francisco Roger’s 18th-century recipe book. The adjective bo (“good”) indicated a finer, higher-quality sauce.
What’s the difference between mayonnaise and aioli?
Traditional aioli is made with garlic and, in its purest form, only garlic and oil. Mayonnaise drops the garlic and is based on an emulsion of egg and oil.
