There's one word everyone is waiting to hear, one term the diners sitting at the long wooden tables, eating their traditional meals and cradling their dangerously empty cider glasses, are straining to catch.
Chairs scrape and feet pound when that word rings out, as everyone leaves their plates of bacalao and chorizo and crusty baguettes and heads to the barrel room, where huge wooden kegs rest in a cool, damp space. The guy who issued the call, the "txotxero", screws a small handle into a tap sunk deep into one of those barrels, gives it a twist, and a long stream of fresh cider cascades in a brilliant green arc towards the concrete floor.
Txotx. It's pronounced "choch", and it's the Basque name given to the tap in the side of the barrel. It's also the acknowledgment that the tap is about to be turned on, that everyone in the cider house should follow the txotxero into the cellar to fill up their glasses with sour, funky, delicious cider.
This process is heavily traditional, as are so many of the rituals on display here today, precious rites that have gone on for hundreds of years. And no one explains them to you, either. No one walks you through the protocols. You learn on your feet here, with a cider glass in hand. You're welcomed into the Basque clan as long as you can figure out where to go and what to do as part of it.
This cider house – or "sagardotegia" in Basque – is called Astarbe. It's set in a beautiful stone farmhouse in the hills above the town of Astigarraga, near San Sebastian. This is the heartland of the Basque cider tradition, the place where it all began, where an amazing 19 cider houses still exist in a town of little more than 6000 inhabitants.
Astarbe threw open its doors in 1546. Almost 500 years ago. Today's txotxero is a young, affable guy called Joseba Astarbe, who is the 15th generation of cider makers from his family. There was no question he would continue the tradition, either. "Cider is very popular here," he says as we crowd around in the cellar, waiting for the txotx to be opened. "Many people still want to do this."
Part of the reason Basque cider is so popular is because it's delicious. It's not like the cider you've been drinking at home. Here it's sour. It's uncarbonated. It has a definite funk to it. You can really taste the apples, you can feel the connection the drink has to the earth, to the land that's so important to these fiercely independent people from the north of Spain.
The cider has close ties, too, to another element vital to the Basque identity: the ocean. The coastal dwelling Basques have long prided themselves as great seafarers, ocean-goers who as far back as the 16th and 17th centuries were casting their fishing nets far and wide, hunting whales and cod in the faraway seas of the North Atlantic.
Those ancient journeys meant spending eight or nine months at sea, and the sailors needed sustenance. Water kept in barrels would go bad. Cider, however, would keep, so Basque ships were laden with millions of litres of the stuff, allowing their fishermen to travel further, to catch more, to become richer.
Those ancient sailors would drink cider, and they would eat salt cod, the stuff we now know as bacalao, cured via a process invented, if you believe the locals here, by the Basques. It's no coincidence that salt cod features heavily on the traditional cider house menu – the perfect link to the past.
You'll find bacalao on every menu, because one of the quirks of Basque sagardotegias is that they all serve essentially the same menu. First, a little snack, maybe some chorizo or fried pork on a slice of bread. Next, an omelette filled with onions, parsley and bacalao. Then, large hunks of salt cod topped with fried onions and capsicum. And finally the main course: a "txuleta", an 800-gram rib-eye steak grilled over coals, served unadorned, designed to be shared between two.
"It wasn't always this way," says Joseba. "People used to come to cider houses and just drink. But they were getting too drunk all the time. So the cider-makers started cooking omelettes and bacalao. Then people would bring their own steak to grill, so that was added to the menu."
Today at Astarbe, we're following tradition. We've eaten the snack, we've tackled the omelette, we've finished off the bacalao. We're waiting now for the steak, for that whopping piece of meat to be clunked down on our table.
While we wait, txotx. Here, again, there are unwritten rules, centuries-old traditions to divine.
The glass you're given is large, but you never fill it up. You never go close, in fact. The idea is to just take a small amount, about a quarter of a glass, to keep the cider as fresh as possible, to allow you to sample from as many barrels as you can, to taste the difference.
Once the txotxero opens the tap, you place your glass under the stream, holding it at an angle, letting the cider explode in a shower of green sparks as it hits the side of your glass and tumbles in. You dip the glass as low to the floor as you can, allowing the maximum velocity as the cider strikes, before moving it up and then out of the way for the person behind to catch the stream without letting any hit the floor.
You can imagine how this goes, given the cider is served on an all-you-can-drink basis. At the beginning of the day it's a formal and respectable process. As the afternoon rolls on, however, it gets progressively rowdier. Pretty soon you don't even have to wait for the call of, "Txotx!" There's someone stationed in the cellar permanently, dealing with the thirsty traffic, turning tap after tap.
We take our cider and return to that long wooden table, sitting down just in time to see the txuleta arrive, tucking into this typically rare and bloody joint of meat with just a crusty baguette to pair with it. Later we'll be served the standard dessert: slices of local cheese with quince paste; fresh walnuts still in their shells.
Most cider houses are only open during the cider-making season, from January to April. The cider-makers bottle what's left of their product at the end of the maturation process, at the end of the txotx season, then close their doors for the year.
It makes a trip to a sagardotegia a special event, a cherished staple on the Basque gastronomic calendar. You can feel the excitement; you can tell it's a celebration. All it needs is the txotx.
Ben Groundwater travelled at his own expense.
Singapore Airlines flies twice weekly from major Australian ports to Barcelona, via Singapore, with onward connections to Bilbao. See singaporeair.com or call 13 10 11.
The Hotel Maria Cristina is San Sebastian's only five-star hotel, located in the heart of the city. Rooms start from $430 per night. See hotel-mariacristina.com
Astarbe Sagardotegia is located in Astigarraga, about a 15-minute drive from San Sebastian. It's open daily from January to May. A set meal with all-you-can-drink cider costs €35. See astarbe.eus
FIVE MORE BASQUE TRADITIONS TO EXPERIENCE
On January 20 every year, the city of San Sebastian explodes into a riot of drumming as participants take to the streets for the 24-hour Tamborrada celebration. It seems like the whole town is out for this festival. Don't expect to get much sleep.
This is a huge festival that takes place every August throughout Basque Country, though most notably in San Sebastian and Bilbao. It includes parades, sporting demonstrations, concerts, and in San Sebastian, a fireworks competition.
A pintxo is a Basque-style tapa, a very small portion of food, and a pote is the word used for a drink. Put the two together and you have the regular Thursday night special "pintxo pote", when you can get a snack and a drink in most San Sebastian bars for between €1 and €2.
This might just be the most cherished and fiercely guarded Basque tradition of all: the language. Euskera is a unique tongue unrelated to any other in Europe. You'll hear it spoken throughout Basque country, though particularly in rural areas.
Pelota is a sport, a little like a cross between European handball and squash. It's a traditional Basque game played on outdoor courts that involves teams of two hitting a ball either with paddles or their hands, and it's something you'll rarely find outside Basque Country.