Q. Does beer lose its flavor when it gets warm? Seems like cold beer allowed to warm, even if it's cooled again, tastes funny. This seems especially true of better quality beers. Is there an explanation?
A. "Beer flavor is very much a temperature thing," says Tim Keck, head brewer at Frederick Brewing Company in Frederick, Md.
When beer is very cold, the bitterness of the hops is accentuated, but as it gets closer to room temperature, the sweetness of the malt is more dominant, Keck says.
After prolonged exposure to the air, beer will go flat as the carbon dioxide seeps out, Keck says. That can make the taste less pleasant.