I've been on a mission for the perfect hot chocolate for some time now, experimenting in my kitchen with warming milk and powders and buttons and marshmallows. After a few particularly spiteful cold days this spring, there's almost nothing at once as soothing and slightly bold as a large cup full of chocolate. Friends of mine swear by Butlers, or the Starbucks Signature Blend, but I'm well over the mainstream. They're a fine fix if it's cold outside and your sweet tooth is calling you, but if you're looking for hot chocolate like you've not had before, you'll have to go west for it. Far, far west. It's an adventure worth undertaking.

There's no bus that leads out there. You'll have to drive 40 minutes from Galway – or a No 10 down a winding, hilly road from Kinvara. You could hike it, too, on a sunny day. Part of the adventure is how remote and unexpected Hazel Mountain Chocolate is, in a valley nook in the Burren.

The tearoom has an old-world quality to it even upon arrival in the car park: a cottage with painted pink shutters, a carved wooden sign leading visitors to the factory and shop around the side. My companion, Serena, and I visit at lunch hour on the last day of spring midterm, so the cafe is teeming – we nip around the factory side to investigate.

When you envision a chocolate factory, I'm sure that images of Gene Wilder prancing about a hyper-coloured candy land are the first thing to pop to mind. This is not what is happening here in the Burren. Chocolate is treated here with dignity and curiosity, not as a frippery. The tour space is a beautifully designed showroom for the chocolate it produces: wooden panelling, exposed high beams, truffles and chocolates presented as though treasures or jewels. The air is thick with a dark, heady scent. Darragh, our guide, explains that this is because the cocoa beans ferment slightly in their shells. He says that often people will come in and remark that the place smells like a chipper. I close my eyes and inhale deeply: he's not wrong. There's a vinegary quality to the atmosphere that's a little hard to place your finger on: a far cry from the vanilla-sugar vortex I'd expected. This fermented sourness is why dark chocolate is largely considered an acquired taste. I taste a shard of chocolate with pecans from a dish; it has an almost Christmas-cake quality, rummy depth to it. This isn't candy you fist into your mouth in heaps: this is something slower.

Several large burlap sacks of raw cocoa beans stand around the entrance to the mill and roastery: not unlike coffee beans in their original form. The roasting and treatment of the beans, in fact, is also similar to how artisan coffee is manufactured. Each roast is from single origin beans, which means that each batch of resulting chocolate retains a distinct flavour palette. Darragh explains this via a map on the wall: Swiss chocolate – and chocolate in that style, including the supermarket brands we’re used to – uses blends of beans from all over the world, pumped up with sugar and milk, so they taste far removed from their origins. Here in the Burren, they’re seeking something more authentic.

Darragh points out that this is what people are looking for in their coffee lately – this specificity of origin or blend, products made by artisans with care and consideration – and predicts that in 10 years’ time, it’s where chocolate will be, too.

After the beans are roasted, they’re milled for up to two days, then taken to the kitchen to be transformed into huge slabs, which will eventually, after three weeks of ageing, be crafted into bars, truffles, eggs, hearts and, of course, cocoa for hot chocolate. On shelves above the various pieces of industrial machinery, huge bars are locked in plastic, numbered and dated by hand.

There's something very refreshing and honest about it all, this specific dedication to a product. The bars of chocolate for sale are dark, heavy slabs. More than €5 a pop, but you're not going to be eating five of them in a row while chain-viewing Netflix shows. A single square of Venezuelan Bean 72% Cacao Single Estate adorned with cinnamon, cloves and ginger to give it a light chai buzz will be more than enough with your cup of tea.

Speaking of hot drinks, there’s something I came here for and the lunch rush is over – so out to the cafe we go. The decor lands somewhere between Scandinavian minimalism and hodge-podge Irish hominess: the walls are packed with photographs of the three generations of the Connolly family who have come through this building. Hazel Mountain opened as a chocolate factory on Valentine’s Day in 2014, but it was lived in long before that. My companion and I order one of each kind of hot chocolate – one with milk, one without – and we sit in the window while we wait. The menu is a select list of delicious cakes and savoury meals, each innovatively incorporating the cacao produced on the premises. Think grilled halloumi with plum and chocolate chutney, or cacao black pudding toasties, or cacao butter hummus sandwiches – traditional tearoom fare stepped up a notch.

The two mugs arrive sharply and we sit there, unsure of which one to take – but settle on sharing spoonfuls of each. The milk-based hot chocolate is frothy, exactly hot enough but not scalding. The water-based one is richer, stronger and hotter but no less sweet or drinkable – crowned with a puff of fresh whipped cream and some grated fresh chocolate to set it off. We drink them both in turns, unable to decide which is better.

Beside us, a girl of about seven sits down at a table by the fireplace with her grandfather. The table dwarfs her, and her eyes are wide. A tea tray is rolled in, on top of which sits two volcanic-looking slices of chocolate cake, rich and black, with shining hot icing on top and in the middle. Two matching peaks of white cream, two forks. She and her grandfather eat as Serena and I nurse our hot chocolates. What bliss to be that small and in front of a slice of cake that big. No, there’s no chocolate waterfall or fizzy lifting drinks, but Hazel Mountain holds its own quiet, delicious kind of magic that cements the chocolate factory as a true golden ticket of the west.

Hazel Mountain’s tearooms are open 10am-4.30pm every day except Monday. Special hikes and chocolate tastings run throughout spring