For Espontáneo, the Sour savants started by crafting a base with local pilsner malt and local/heritage raw wheat, boiled it extensively with whole leaf hops, and then transferred it to their coolship to inoculate the wort with 100% natural airborne yeasts and bacteria. After primary fermentation, they patiently let the brew mature in tequila barrels, added wildly fragrant black limes, and finished the beer with sea salt.