Last spring, Indianapolis’ Grant Curlow posted a YouTube clip that could make even the most casual beer fan drool.

In his prosaically titled Beer Cellar Video, Curlow spends six minutes and 48 seconds slowly and nearly wordlessly panning over a concrete basement where, arranged in stacks, racks and scattered across the plywood floor, are more than 700 bottles of coveted brews, such as Firestone Walker’s barrel-aged XII and Three Floyd’s wax-capped Dark Lord Russian imperial stout. Then there’s his Belgian bounty, including Trappist ales and sour lambics, like Drie Fonteinen. Some of his beers are older than Curlow’s 24 years—and only going to grow older. “I’ve got lambics down there I’m waiting for 20 years to try,” says Curlow, who started collecting during college and recently parlayed his passion into a job as the craft-beer specialist for World Class Beverages. “I’m in no rush to open them.”

Welcome to the new world of old beer. Like wine, beer has the capacity to age, evolve and develop complex new aromas and flavors. Think that Sierra Nevada Bigfoot Barleywine is a rich treat right now? Try it in 10 years, when it has mellowed into a smooth elixir worthy of a snifter. Time, combined with yeast and bacteria, can buff a beer’s rough edges and unlock its full potential—or, given a few months too many, create a liquid best sent down the drain.

Aging beer isn’t an exact science. Still, you can use tricks and tactics to tilt the sands of time in your favor. By creating an ideal climate, selecting the right beers to put to bed and following storage protocols, you can start a cellar of your own, even if you live in a skyscraping apartment.

The Air Down There

After committing to build a beer collection, the first step is creating a safe, cozy environment in which the brews can slumber undisturbed—the cart before the horse. Some of the best advice on building a cellar can be found in Lovell, Maine, a tiny town near White Mountain National Forest that’s home to Ebenezer’s Pub. Despite its rural digs, Ebenezer’s is a world-class Belgian bar and possibly the country’s foremost repository for vintage beer. “I’m trying to build a time machine,” says owner Chris Lively, 37, of his climate-monitored, 2,700-square-foot cellar. It features a security system to guard his 1,000-plus bottles that span more than a century of brewing. Like a liquid Library of Congress, “I want to have these beers here 100, 200 or 300 years from now. We cellar beers for the interest of the beer world.”

For your interests, Lively suggests a cellar, or a basement, where the temperature will remain relatively low (about 55 degrees F is ideal, give or take five degrees), with narrow temperature fluctuation; a range of more than 20 degrees will wreak havoc. This also holds true for wine, which you can cellar alongside beer. (Red wine is typically stored at 50 to 55 degrees, and white wine is best aged at 45 degrees.)

Unlike wine, which rests on its side to keep corks moist, all beer—even if it has a cork—should be stored upright, says Alan Sprints, 51, founder of Portland, Oregon’s Hair of the Dog brewery. “That way, sediment remains in the bottom. Store bottles on their side, and sediment kicks up when you pour.” Utilizing a shelf system, or a fridge, will help prevent accidentally sending an upright bottle crashing to the ground.

The next step: block sunlight. Beer is photosensitive. Glass bottles let in UV rays, which cause chemicals called isohumulones (they help make beer bitter) to decompose and create compounds found in skunks’ spray. Voila! Skunked beer.

Another cellaring enemy is humidity. “If there’s not enough humidity, the corks will dry out,” Liveley says. “If there’s too much humidity, it could damage beer and invite black mold,” which can enter through the cork or a loose crown cap. Lively likens black mold to a silent, deadly assassin. “Your beers will die a slow death,” he says. Keep them safe with an air purifier, while using a humidifier or a de-humidifier to calibrate the climate. The optimum atmosphere has “the kind of humidity you have in fall or spring” on the East Coast, Liveley notes. (An ideal humidity range is about 50 to 70 percent.) What you don’t want is to walk into your cellar and feel a warm, damp rush. That could signify mold in the air, says Lively, who recommends a mold analysis every two years. “It’s literally a bacterial war in the cellar.”

Though underground storage is ideal because temperatures tend to stay steady, it’s not imperative. Instead, you can opt for an inexpensive wine fridge or, if that’s cost-prohibitive, “look toward a bedroom in the middle of your house”—far from windows, so the temperature is more stable—“and use the closet,” suggests Bill Sysak, 48, the beverage supervisor and certified Cicerone at Stone Brewing World Bistro and Gardens. “Buy a $2 thermometer and check the closet over a couple seasons. If you don’t have extreme temperature fluctuations, you know you have a place that’s safe for beer.” (He also recommends a humidity meter.)

Before starting at Stone, Sysak spent more than 25 years amassing one of California’s—if not the country’s—finest collections of cellared beers. At one point, Sysak amassed more than 2,500 bottles, which he stored everywhere from a three-door cooler in the garage (the convenience-store relic is not turned on, yet it maintains temperatures between 62 and 65 degrees) to a cabinet under the bathroom sink. “I also have three smaller wine coolers and bottles stuck under the house,” Sysak says. “The point is, a lot of my beer isn’t refrigerated.” But what if you live in Las Vegas or another scorching city? No worries, says Sysak. “If you don’t have a beer refrigerator or a cellar, and your average indoor temperature is in the high 60s or 70s, you can insulate bottles with [Styrofoam] wine shipping crates,” Sysak says. “Craft beer is much more durable than people think.”

Brews to Choose

Now that your cellar, fridge or closet is secured, the fun part is filling it. However, not every beer should age. Most are best as soon as they’re bottled, especially hop-forward pale ales and IPAs. Hops are most pungent and aromatic when fresh, and even a few months will dull their character. (For example, the label on Russian River’s amped-up IPA Pliny the Elder reads DOES NOT IMPROVE WITH AGE! HOPPY BEERS ARE NOT MEANT TO BE AGED!)

When selecting beers for aging, Sysak suggests following general guidelines. First, it’s beneficial if a beer is 8 percent or stronger, since an elevated alcohol profile will typically become smoother, mellower and more agreeable. Another rule of thumb is to select a darker, maltier beer, because the sweet, residual sugars tend to soften over time. Above all, ensure that the beer is bottle-conditioned, wherein live yeasts lurk inside the bottle.

“Though the yeast doesn’t continue to ferment, it helps the beer age,” explains Hair of the Dog’s Sprints, who always finishes his beers with fermenting yeast. “All of our bottle-conditioned beers are meant to age,” he says of creations such as “Dave,” an English-style barleywine brewed more than 15 years ago and boasting 29 percent ABV. “It’s so much better now than it ever was. That shows the patience it takes to hang on to a beer for an extended period of time.”

So which beer styles are worth the wait? Sysak recommends Belgian strong ales, barleywines, imperial stouts and, bucking the high-alcohol guideline, sour Belgians, such as lambics and Flanders red ales. With aging beer

, there are always exceptions to the rule, Sysak says. “I have Tripels, saisons and blonde ales that are 10 or 15 years old and beautiful.”

Other outliers include ales spiked with wild yeasts, such as Brettanomyces. They’re often unstable, since the yeast rapidly works through a beer and alters its character—one month it’s sublime, the next it’s undrinkable. However, Brett-dosed beers, such as Belgium’s monk-made Orval and Sanctification from California’s Russian River Brewing, respond well to cellaring. “They don’t age into the 10- to 20-year range, but they do grow complex and amazing,” Sysak says. (Additionally, Sysak says beers boasting multiple strains of yeasts and bacteria, such as Lactobacillus, hold up better.)

If you can swing it, purchase at least two bottles of each brew—or more. That way you can crack open a bottle every so often and taste how the beer is aging. Plus, you’ll have spares in the event you want more of a good thing, or need to replace a bottle ruined by a bad seal. “Historically, I buy large quantities,” Sysak says. “If you have a beer that you enjoy and it has a proven track record, it’s nice to get a case, whether that’s 12 bottles or 24,” Sysak says.

However, you don’t want to overdo it on a single beer. While you may be crazy for Founders Kentucky Breakfast Stout, “you never know how your taste buds will evolve,” says Curlow, who started out collecting strong stouts before focusing on Belgian lambics and Trappist ales. “Keep your cellar varied.” Since Curlow started saving beer as a college freshman, it’s a wonder he resisted the temptation to dip into his stock. “You buy more than you can drink,” he says. “That still holds true today.”

A Matter of Taste

Pouring and sampling is a critical way to determine how a beer is developing before it ends up past its prime. Though an expiration date isn’t stamped on the bottle like a carton of milk, beer does have a limited lifespan. “I have beers that are 50 years old, but for beers that can be aged, the average lifespan ranges from a couple years to eight to 10 years,” Sysak says. Taste. Evaluate. Wait. But don’t wait too long. “At five years, many beers begin to show signs of deterioration.” Typically, higher-gravity barleywines, imperial stouts and old ales have the longest shelf life. “There are rare bottles of English ales out there that are over 100 years old,” Sysak continues. “Of course, they’re a crapshoot just like old wine. You can pay an exorbitant amount for nectar or vinegar.”

Settling on the ideal aging time takes trial and error. “Try it fresh, then anywhere from a month to six months to a year apart to see how the beer ages,” Sysak says. “There’s always that time when you wonder, ‘Should I wait one more year? I like how that flavor is developing.’ Then you try it and go, ‘Shoot, it’s past its prime.’ ”

When aging beers, clunkers come with the territory. “I know there are going to be some duds, but we just have to suck it up when it happens,” says Dave Blanchard, 41, the cofounder of Decatur, Georgia’s, Brick Store Pub, where vintage beers are stored in an adjoining, underground bank vault. In 2005, the bar began acquiring close to 500 different varieties of age-worthy beer, refusing to release them until this fall. “It was a big gamble, because I know some of the vintage beer won’t be as good after aging,” Blanchard says. “It’s a big leap of faith.”

To make that leap of faith a little less daunting, Sysak suggests turning to resources like RateBeer.com and BeerAdvocate.com, which have active forums dedicated to aging. “If you post, ‘I have a 2003 AleSmith Speedway Stout. Has anyone opened it lately?’ sure enough, a dozen people will respond.”

Combining sensory analysis with crowd-sourced wisdom will allow you to make minute adjustments. If your beer is close to peaking, transfer it to a cooler environment to slow down aging. If you’d like the beer to age faster, slightly elevate its environmental temperature. “I’ve taken imperial stouts that have a hot, fusil note”—that is, alcohol—“and increased the cellaring temperatures into the high-60s,” Sysak says. This slightly oxidizes the beer, creating a sweet, sherry-like nuance. “Brewers will never say to do this,” Sysak says, underscoring a simple point: When it comes to aging, you can create the rules as you go along.

Pop Your Tops

After creating, stocking and maintaining a cellar, it’s easy to imagine that you’ve just built a beer museum. But remember, one of the pleasures of building an enviable collection is reaping the fruits of your labor.

For Sysak, savoring and sharing aged beer is part of the fun. He once cohosted (with Tom Nickel, of San Diego’s O’Brien’s Pub) a vertical tasting of Thomas Hardy’s ales (a classic English beer that’s no longer brewed) from the first release in 1968 to 2004. Even crazier, for 10 years he hosted a party on his birthday dubbed “the largest, most extreme private beer party in the world.” Every 10 minutes for 12 hours, Sysak opened two rare beers—say, a De Dolle Stille Nacht Reserva or 1999 Belle Vue Selection lambic—along with up to 20 kegs of beer “in case you got thirsty in between the nine minutes of beer pours,” Sysak says of the event, which sometimes swelled to 250 people.

Of course, opening an aged beer doesn’t require a blowout. “One thing I’m most proud of is that people use my beers to celebrate special occasions,” such as birthdays or anniversaries, says Hair of the Dog’s Sprints. But even that’s too formal a reason for Curlow to crack a rare treasure. “You don’t need a reason to open a cellared bottle,” he says. “I love bringing friends over and popping open something unusual. Whether it’s a random Thursday or Sunday, when you pop open the bottle, it’ll be the celebration.”