I'm a brewer that's done many styles and researched beers around the world. I thought I'd provide some notes about that beer:
From what I believe, they use beechwood to start a fire in what looks like a pizza oven. This oven has a round opening on the top, about 3 meters in diameter.
A metal cage is filled with large boulders, and lowered into this fireplace. The rocks pick up the heat and flavour of the fire, and is raised by a chain, and dropped into the kettle. The wort (unfermented beer) is heated, sterilized, condensed, and flavoured, from this as a heat source. Traditionally we boil using steam or direct fire in a copper kettle. This method of heating has a large initial boil and provides caramelization. It also brings in components from the wood in the fire.
Another way that you can get this into a beer is the way the Scots do it for their peated single malt whiskies. When malting, the barley malt gets smoked over some smouldering peat. The husks take on the smoke and is recommended to not move this malt around when it's bagged, as the smoke rubs off. I've used this malt in some batches, but it didn't give any notes. My peated malt was imported from England by myself.
Since I now have my WSM, and I have a very local supplier of Irish peat, I've used a chunk of this stuff to smoke a chicken, and it's fantastic. I can make peated malt now, and was trying to contact local brewers to see if there was a market for domestic peated malt.
Cheers