Boiling the Wort Once the liquid wort has been drawn off the grain solids, the brewer runs it into a large metal tank, adds hops, and boils it vigorously for up to 90 minutes. Boiling converts the insoluble hop alpha acids into their soluble form and develops the beer’s bitterness, and inactivates the barley enzymes and so fixes the carbohydrate mix—a certain portion of sugar for the yeasts to convert into alcohol