How long does beer last until it goes flat?

Question

At room temperature.

Answer 1

Formaldehyde wouldn't affect whether the beer was flat, only preserved. The amount of CO2 in the beer determines if it's flat.

If it's sealed, you're good. If it's not sealed, as I assume this is, then it immediately begins to release the carbon dioxide in bubbles. The rate it does that will be determined by how cold the beer originally was. So, let's say a standard American beer from the fridge is opened (at about 45 degrees F) and placed on a table at room temp, with average barometric pressure? At about 45 minutes I'd call it a wounded soldier and dump it. Technically, it will retain some carbonation for a significant amount of time though. I'd guess at least 4-5 hours. (I've dumped opens the morning after and seen enough foam to declare carbonation.)

Answer 2

If it is sealed. and it is not Coors or MGD it will last almost forever. As most beers contain formaldehyde (also known as embalming fluid) as a preservative. Coors and MGD have no preservatives and they will spoil in about five hours at room temperature.

Answer 3

110 Days from born on date. I received this information directly from a district manager Anheuser- Busch.

Answer 4

if sealed until it expires. if opened a day max.