Léonard Parli was a candied fruit confectioner who, like many fellow-countrymen, fled Switzerland in the 19th century to escape famine. He ended up in Aix and in 1874 set up a company to make the city's famous speciality, the calisson.
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After inventing a machine to speed production, Parli, pictured, was by 1908 turning out 300 kilos / 660 lbs of the little almond-shaped delicacies a day. Claiming to be the first calisson factory in Aix, it is still run by Parli's family.
Today the Parli establishment sits where it has been since 1910, just down the road from Aix Centre railway station (Parli picked the spot the better to send his produce out quickly). Above the door, carved into the stone, is his crest, a Swiss cross framed by palm branches signifying Provence.
Inside, the rococo little shop offers calissons - of course - both in decorative cellophane bags and the distinctive white, lozenge-shaped box used by all calisson manufacturers.
Choose the latter if you're not intending to eat the calissons right away: they will keep longer - up to ten months - in the traditional packaging.
The Leonard Parli calissons were confected in an annexe behind the shop until June 2012, when the factory moved a little out of town to the suburb of Les Milles, where it's still possible to take a tour behind the scenes.
It remains a very small-scale operation that employs a couple of dozen people, depending on seasonal demand: at peak times, such as Christmas, the factory produces 500 kilos / 1,100 lbs of calissons a day. The other surprise is how much of the process is done by hand.
You put on a little cloth bonnet to take the tour. The main ingredients of the calisson are all from the Mediterranean: preserved melon and orange peel and almonds.
By regulation, the calisson contains a minimum 30% of almonds; the Parli recipe has 42% (the mix varies slightly from producer to producer, as does the taste of the result). Manufacturers now import almonds from Spain, since Provence no longer produces them in sufficient quantities.
First the preserved melon, orange peel and blanched almonds are ground together coarsely, then more finely in a vintage machine dating back to the 1970s with granite wheels.
This, the Parli people claim, prevents the almonds from being crushed too completely, thus losing their oil and their flavour: the texture of this paste should remain granular. Fruit syrup is added, then the paste gently heated and left to rest for 48 hours.
The machine which punches the paste into the calissons' delicate shape is intricate and requires two people to operate it.
One worker applies the classic glaze of very thin white royal icing painstakingly by hand while the other gathers the shapes from the mould.
Finally, the calissons are put in the oven for the icing and paste to set. No wonder they're expensive, wherever you end up buying them.
Leonard Parli offers free tours by appointment to a minimum of ten people. Most visitors arrive in guided groups, but you can make an appointment to merge with one of these if you're travelling individually (see below for the email address).
Factory visits take about half an hour and is available in English (check first that there will be an English-speaking guide with the tour you plan to take). It includes a tasting and there's no particular pressure to buy, though few people are likely to leave empty-handed.
Even if you resist the calissons (and they are an acquired taste), the Léonard Parli Confiserie also produces other specialities such as cantaloupe melon preserve with kirsch, a Seville orange and dark chocolate marmalade and peppermint sweets.
There's also something called Kirschbescué, a recipe invented by Parli in collaboration with a relative who had worked as a pastry chef at the court of Queen Victoria, then with the Czars in Russia.
The resulting Anglo-Russian-Swiss-provençal confection is a decadently rich, boozy and delicious cake containing preserved fruit and steeped in kirsch.
Other variants on the calissons include versions with bright, multi-coloured icing, the cabosson, a calisson coated in dark chocolate, and crème de calisson, a spread made of the basic calisson ingredients mixed with apricot syrup. All these items can also be ordered by mail on Léonard Parli's website.
Other calisson tours:
In Aix's Old Town, the Confiserie Genis has tours by appointment to large groups, in French only. 1 rue Gaston de Saporta, 13100 Aix en Provence. Tel and fax: (+33) 4 42 23 30 64 (this shop does not have a website).
Outside the centre of town, factory visits are offered by Atelier Calissoun in Loubassane, the Puyricard Chocolaterie which is, as its name suggests, primarily a chocolate maker based in the village of Puyricard to the north of Aix.
The biggest of the calisson producers, the Confiserie du Roy René, is based in the industrial suburb of La Calade to the north-west of Aix.
In 2014 Roy René opened a very large new visitor centre with a museum, boutique and facilities for tourists to take classes in making calissons. 5380 route d'Avignon, quartier de la Calade, 13540 Aix en Provence.
The manufacturers of calissons d'Aix enjoy an official IGP label: Indication Géographique Protégée, a slightly less strict version of Appellation Contrôlée.
This means they can only be called calissons d'Aix en Provence if there are made in a strictly delimited area of Greater Aix. Their motto underlines this: "Le Calisson: d'Aix en Provence et de nulle part ailleurs" ("From Aix en Provence and nowhere else").
Of course, as with many other IGP and Appellation Contrôlée products, you will find copycat and lookalike imitations from outside the region, often marketed as calissons de Provence.