Every January through April, the barrel rooms of Astigarraga's sagardotegiak echo with a single shout: txotx. The word signals the opening of a thousand-litre chestnut cask, and within seconds a thin amber stream arcs six feet into the air while diners queue with their glasses tilted. The ritual is centuries old, rooted in the need to taste each barrel for oxidation before committing it to bottling, but it has evolved into the social spine of Basque winter. Astigarraga, a village of fewer than six thousand residents five kilometres south of San Sebastián, produces more than half of Gipuzkoa's natural cider. Its fifteen licensed cider houses occupy stone farmsteads that date to the sixteenth and seventeenth centuries, their cellars carved directly into hillside rock to maintain the cool, stable temperature required for slow fermentation. The apples—Errezila, Urtebi Haundi, Gezamina Handia—are harvested in October, pressed within days, and left to ferment in open vats without added yeast or sulfites. By December the cider is sharp, pale, and faintly effervescent, registering between four and six per cent alcohol. The traditional season runs from mid-January, when the first barrels are tapped, through late April, when stocks run low and the cycle begins again. The museum at Kale Nagusia, 48 in Astigarraga anchors the sagardotegi trail. Its guided tour unpacks the full production arc: the hand-carved presses, the oak and chestnut cooperage, the gravity-fed bottling lines that replaced manual corking in the 1970s. The entrance fee of five euros includes both the tour and a seated tasting led by the house cidermaster, who pours from three barrels to illustrate tannin variation across apple varieties. Visitors learn to catch the stream at arm's length—a posture that aerates the cider and delivers its fleeting carbonation intact to the palate. Beyond the museum, a San Sebastián traditional cider house tour with lunch tour connects the tasting ritual to its culinary mirror: the sagardotegi menu. This fixed feast has remained largely unchanged for a century. It opens with tortilla de bacalao, a salt-cod omelet served at room temperature, followed by pan-fried cod with green peppers, then a rib-eye steak grilled over vine cuttings, and finally Idiazabal cheese with quince paste and walnuts. The meal is punctuated by repeated trips to the barrels—each txotx call an invitation to refill and return. The cider's acidity cuts through the richness of the steak; its low tannin and brisk finish reset the palate between courses. The experience is communal by design, with long wooden tables, no written menu, and a pace dictated by the barrel rather than the kitchen.