It’s the smell that hits you first: a ureic stench so thick it feels like something solid is foraging up your nostrils. Tourists are given sprigs of mint or rosemary, like the nosegays carried by Renaissance gentlefolk. But if you want to be accepted by the tanners, you have to go unprotected. I’m turning up for my first day as an apprentice tanner, in the old city of Fez, with nothing to filter out the odours. 

The Ain Azletoun tannery squats at the back of a zig-zag of wood-scaffolded, flaking-plaster alleyways. Pressing yourself to a gap-toothed mud-brick wall, you breathe in to let the hide-laden mules pass (along with the smell, they are the best clue you’re heading in the right direction). Following your nose, you’re guided by the thickening stench - a toxic mixture of lime and pigeon excrement. It builds to a peak outside a fortress-like mud wall, where piles of goat hides hug the sides, like the bones of slain adventurers outside a dragon’s lair.

Inside, you slide through a soggy passageway of wooden joists and crumbling brick, crabbing up a wall-ledge to lever yourself onto a narrow walkway. Here, you can watch the first stage of the dyeing process: a honeycomb of stone pits, greasy with limewater and speckled with goat hairs. Only the most reckless would perch on the edge: the slightest stumble is likely to pitch you right into the acidic potions, and there’s a reason the workers go about in knee-length waders!

My guide into this secretive world is a curly-haired junior tanner called Najib. After several coaxing glasses of mint tea, he takes me along, and his boss accepts me as an unofficial apprentice. They’re a tough, no-nonsense bunch, thick in the shoulders and thighs, the latter bulging out of crinkly leather shorts. Paid per hide (at a rate of one dirham – less than 10 cents - a piece), they haven’t any time to mess about, and it shows in their brisk, unstinting work-rate.Relaxation is ciphered by the cigarette packets scattered around the work-cells and the tunes playing on many of the tanners’ mobile phones (Najib’s favourite is Busta Rhymes, but his boss is a Michael Jackson die-hard). 

Once a batch of hides has been soaked, they are carried to a corrugated iron shed and dumped inside the ghaseel or ‘washer’ – a wooden barrel big enough for a giant’s beer keg, which is turned by an electric pulley. This is one of the simpler jobs, which means it’s allotted to me: hoisting hides alongside Najib, dropping them into the barrel, our voices lost beneath its creaky rumble and the splash of water frothing out of a grille in the side.

The next stage is my favourite. Bearing a dozen hides at a time, Najib and I climb a narrow stairwell. Up on the rooftop, burning yellow in the sun, are hundreds of be-saffroned pelts. We tiptoe between them, picking our way across the cracked cement, carrying our piles to a corner of the roof. Oil and saffron dye are added from a bucket, before we lay our skins beside the others, placing stones at the edges to hold them fast. It’s a beautiful spot, surrounded by the ripple of Fez’s majestic roof-scape: sparrows wheeling over minarets and pigeon coops, black smoke puffing out of chimneys fuelled by olive pits, all framed by the gentle swell of the Middle Atlas foothills.

Long regarded as Morocco’s spiritual capital (ever since its founding at the end of the 9th century by a holy warrior), Fez is equally well-known for its workshops. This is a place where things get made. One of its most famous citizens was the explorer, Leo Africanus, who described the range of trade in the early 16th century – everything from wool-chapmen and wax-makers to snake-charmers and necromancers. Many of these trades have passed down the generations; and it’s the authenticity of transmission that makes Fez’s products so desirable. As Najib’s boss tells me, ‘we use no chemicals. We do the same way as our ancestors, because it works!’

Najib’s team spends the bulk of its time in the work cells – which are so small and dusty, they feel monastic. Cobwebs dangle overhead and you have to duck to avoid the pelts hanging from the wooden beams. Sitting on scraps of yellow leather, we take turns to wrap our thighs around the balaat (a mushroom-shaped buffing stool), rubbing the skins over the grooves, softening the hides to a creamy leather; whilst other workers usebroad-bladed knives to ‘break’ the skins, slicing off the rough edges.

‘It is hard work, of course,’ says Najib, as the day draws to an end. ‘But my family has worked in the tannery for many generations and we are proud of this.’ Wandering back through the labyrinthine streets of the bazaar, he points a saffron-stained finger at the tannery products around us: from handbags to cushion-covers, shagreen notebooks to sequin-dotted camel toys. Most exciting for him (because these are the products in which his team specialises) are the bright yellow babouche slippers.

‘Now,’ he says, ‘it is time to relax.’

An evening in the hammam is the perfect wind-down. Wielding bars of extra-strong black soap (made from the residue of pressed olives), we rinse off the stains and smells accumulated in the course of the day. By the time we emerge, there isn’t a whiff of the tannery on us. At least, that’s the intention! Which should mean we are able to wander back through the bazaar, without people raising sprigs of mint or rosemary as we pass.

Nicholas Jubber is the author of The Timbuktu School for Nomads: Across the Sahara in the Shadow of Jihad (Nicholas Brealey Publishing, November 2016.)