Brewed from barley, malt, yeast and hops, beer has a shelf life of four to six months out of refrigeration. The ingredients in beer benefit from cooler temperatures, quickly deteriorating when the temperatures rise above the ideal. If you value your beer, avoid disappointment by keeping it in the refrigerator when you are not drinking it. How long your beer keeps inside the refrigerator depends on a variety of factors, including type.

Refrigeration is the preferred storage method for both manufactured and fresh draft beer. The cool refrigerator temperatures of 40 F and below, combined with the dark conditions, slows the oxidation process, which is responsible for giving beer a stale or skunky taste over time. If you do not have enough space in your refrigerator for your entire purchase, refrigerate what you do have space for and choose a cool storage area that is free of sunlight for the rest.

For optimal quality, store commercial beers within temperatures between 40 F and 38 F as soon as possible after purchasing. Unopened bottles and cans of beer keep for eight to 12 months refrigerated under these ideal conditions before deterioration becomes an issue and quality is compromised. Although the beer is still safe to drink after this time period, oxidation eventually begins to set in, making the beer less palatable to the drinker.

Whether you replace the cap on the bottle or apply a seal top over the can, once opened, oxygen enters the beer. When this happens, quality diminishes quickly, refrigerated or not. Open commercial beers only last for one day in the refrigerator before going flat. Although the flat beer is no longer good for drinking after a day, cooking is another story. Flat beer is more stable than beer from a new bottle, making it ideal for your recipes.

Growlers are refillable bottles used to store fresh draft, also known as tap beer. Stored in the refrigerator, beer in these vessels remains fresh for up to one month as long as the growler remains closed. The shelf-life of refrigerated beer in an open growler is considerably less -- only about two to four days. This is because once you open the growler, oxygen enters the vessel, increasing the rate of oxidation.