As prices go up on almost everything you eat and drink, it makes sense to try to get things fresh and keep them that way. Check "best-by" dates; eyeball the produce. Put dairy in the fridge, meat in the meat drawer, and tomatoes on the counter. Soft drinks seem bulletproof, while wine has to be kept cool and out of sunlight. Everyone 21 and older knows this stuff.

Nobody seems to know what to do with beer, however—including a lot of the people who sell it. I see too many six-packs of bottles sitting in glass-front coolers lit by fluorescent tubes. Light is death to beer.

I learned about that and other ways in which beer can go bad by doing a series of experiments on some freshly bottled beer from a local brewery. I put it in bright sunshine. I froze it. I slow-roasted it in the oven. I subjected it to eight cycles of chilling and warming. I felt bad mistreating beer like that, but those beers suffered so other beers could be better. Here's what I found.

Keep your beer in the dark
The beers that sat in the sun got real whiffy; the technical term is light struck, but most of us call it "skunked." (In skunkless Britain, it's called "cat's piss.") Dave Radzanowski, former president of the Siebel Institute, America’s oldest brewing school, explained that part of the chemical makeup of hop oil is light sensitive. When light of a particular wavelength hits it, "there's a photosynthetic reaction which changes that grouping to that of the common 'skunk' aroma." Sunlight and fluorescent light are especially harmful; incandescent light is less potent.

I had my bottles in the sun for more than eight hours—overkill. "If you have a beer in clear glass exposed to direct sunlight, it can go skunky in five to 10 seconds," Radzanowski said. Brown glass offers some protection, but clear or green offers a marginal amount. Some brewers use hop extracts that are immune to light—Miller included—and some beers with a low hops content can get away with clear bottles. But to be safe, buy beer that hasn't been sitting in the light, and keep it in the dark. Cans, of course, keep out all the light.

Don't worry about warming
This is probably the question I get most often. "I bought this beer cold, and then it got warm. Is it still good?" Yes! I'm not sure how this myth started, but it takes many cycles of chilling and warming to have an effect on beer. My program of eight cycles didn't change the beer's taste compared with the cold control bottle. That being said, beer will stay fresh longer in the refrigerator than on a room-temperature shelf. But unless you're chilling and warming your beer every day for a month, just drink it and relax.

Avoid extremes (sometimes)
If you have a choice between sticking your beer in the oven or the freezer, go with the icebox. Of course, most people do neither—but they might leave it in the garage or the trunk of a car.

Extreme heat damages the proteins in beer, giving you a bunch of floaty bits, and can cause nasty aromas to develop: "Like a can of creamed corn, with a scary whiff of gutter stink" is how I describe the smell of my roasted beer.

Freezing a beer, on the other hand, can work out nicely, if the bottle doesn't leak or crack as it hardens. The first keg I ever bought was a half-barrel of Genesee Cream Ale that had frozen solid. We let it thaw slowly, and I still remember it as the best Genny Cream I've ever had: smooth, with a velvety mouthfeel. Freezing also depletes proteins, though not as abruptly or completely as heat does, leaving the beer tasting smoother, if nothing goes wrong. But use this theory with care, or you may have a malty mess in the freezer.

Drink your beer fresh…mostly
Best-by and "born-on" dates are great advantages for the consumer. You can tell if the beer is fresh, and you can get an idea of how fast the store is turning over its stock. But beer isn't milk: It's not harmful or smelly past the best-by date; it just won't taste quite as good. Anheuser-Busch's born-on date is the date of packaging. The company claims that the beer is good for 110 days after that date. If it's not sold by then—something that doesn't happen often—A.B. will pull it off the shelf.

Not all beer is best fresh, though. Like some wines, some beers get better as they age. It's not an exact science, but beers that are more than 7 percent alcohol, not overly hoppy, and bottle conditioned (bottled with yeast) are the most likely candidates for aging. I've had beers more than 20 years old that were fantastic: They are drier than the younger versions and often develop sherried notes that can add depth and complexity to a big beer. Keep them as you would wine—in a cool, dark place with no changes in temperature—but unless the beers are corked, store them vertically.

Now, all I need is someone to tell me the best way to keep coffee beans fresh. Then I'll be set for drinks—morning, noon, and night.