Hold a pint of Guinness up to the light. It is not black. It is dark ruby red. The color comes from roasted barley heated until it is nearly burnt, and the darkness is an illusion created by density, not pigment.
This is the full story — how water, barley, hops, and yeast become the most famous stout on Earth. Why the bubbles sink instead of rise. How nitrogen replaced carbon dioxide and changed the way the entire world pours beer. Why a single brewery in Dublin has been running on the same lease since 1759. And why the drink you thought was black has been red this whole time.
