may deteriorate in a few days It turns out that light in the blue-green to ultraviolet parts of the light spectrum reacts with one of the hop acids to form an unstable free radical, which in turn reacts with sulfur compounds to form a close relative of chemicals in the skunk’s defensive arsenal Brown glass can absorb blue-green wavelengths before they get to the beer inside, but green bottles don’t As a result, green-bottled German and Dutch beers are often sulfurous, and many consumers now expect this! One American brewer with trademark clear bottles developed a modified hop extract that’s free of the vulnerable hop acid, and this prevents its beer from going skunky Serving Beer In the United States, beer is often drunk ice-cold and straight from the can or bottle This is fine for a light, thirstquenching beer, but doesn’t do justice to beers designed to have some character The colder any food is, the less full its flavor will seem Lager beers are usually best served somewhat warmer than refrigerator temperature, around 50ºF/10 C, while top-fermented ales are served at a cool room temperature, from 50 to 60ºF/10–15ºC Beers worth savoring are poured into a glass, where some of the carbon dioxide gas can escape and moderate their prickliness, and where their color and head of foam can be appreciated Beer Foam: The “Head” Beer is not the only intrinsically bubbly liquid we enjoy, but it’s the only one whose bubbles we expect to persist long enough to form a “head” of foam atop the glass Beer lovers even value the ability of the foam to cling to the glass as the liquid level drops, a quality known as lacing (or, in more impressive German, Schaumhaftvermögen) There are many factors that influence foaming, from the amount of carbon dioxide dissolved in the beer to the ... poured into a glass, where some of the carbon dioxide gas can escape and moderate their prickliness, and where their color and head of foam can be appreciated Beer Foam: The “Head” Beer is not the only intrinsically... but it’s the only one whose bubbles we expect to persist long enough to form a “head” of foam atop the glass Beer lovers even value the ability of the foam to cling to the glass as the liquid... known as lacing (or, in more impressive German, Schaumhaftvermögen) There are many factors that influence foaming, from the amount of carbon dioxide dissolved in the beer to the