The beer display at Four Seasons Food Court on Chestnut Street is impressive for an establishment known for its Chinese lunch buffet. Its array of bottles and cans is as large and diverse as any bottle shop in Center City. The bad thing is many of these beers are old. So old that this August, the Four Seasons Food Court had a Christmas vibe going on.

Lined up in the coolers were labels like Slyfox 2015 Christmas Ale, Weyerbacher Winter Ale, Goose Island Winter Ale, Yellow Snow Rogue IPA and…wait for it…Samuel Smith’s Winter Ale Welcome, 2014 edition. Old beer!

Lots of breweries put “best by” dates on their products now, so it’s not like these transgressions were hidden. The Weyerbacher had an expiration date of March 1, 2016. Goose Island’s freshness ran out on January 6, 2016. And unless Four Seasons’ refrigerator is also a cryogenic chamber, odds are the Samuel Smith wasn’t all that tasty, either.

That store might be one of the biggest offenders in Philly, but it’s not the only one. Old beer is a real thing — and the epidemic is getting worse.

Matching supply with demand

Right now there are more than 4,000 US breweries, and if the trend keeps up, the number will hit 5,000 by next year. That’s way more than just a couple years ago. The growth is fueled by drinkers, who mostly love the variety. Instead of sticking with a favorite brand (you know, how your grandfather had “his beer”), people actively seek out styles and labels they haven’t had before.

Stores are answering the demand by stocking more kinds of beer. That makes it harder than ever to ensure it’s always fresh.

“When my partner owned Society Hill Beverage seven years ago, he had around 90 SKUs. We currently have around 400,” says Dan Stevenson, co-owner of The Beer Peddlers case store, referring to what’s known as Stock Keeping Units (each type of beer or package has a unique SKU).

If Stevenson notices beer that’s getting close to being outdated, he holds a “blowout sale” to move them fast. If beer is out of code when it arrives, he says, it gets sent back immediately.

How old is too old?

A recent survey of the bottles and cans on display at The Beer Peddlers revealed few offenders. The only suspect spotted was a 12-pack of Goose Island Four Star Pils with a bottled-on date of Feb. 14, 2016. (While some breweries stamp “best by” dates on their beer, others simply indicate when it was packaged and let you draw your own conclusions.) The February beer was surrounded by other Four Star cases bottled four months later, on June 16. Does that mean it was too old?

Spoiled beer doesn’t poison you, like rotten milk, so there are no rules and regulations about how old is too old. But there is a consensus, which varies by style.

Hoppiness is one of the first flavors to dissipate, so most people agree IPAs are usually best sipped within 60 days of being bottled. The sooner the better, really. California’s Stone Brewing Co. even has a beer called “Enjoy By IPA.” Every bottle comes with a date 30 days after its packaging emblazoned in huge characters on the front label. Stores that try to sell it after that day end up looking obviously silly.

Stronger beers with higher alcohol content have longer shelf lives, but if any light or oxygen comes in contact, those will also begin to go stale, with a cardboard taste showing up around the six-month mark. One characteristic old beer takes on is sherry-like aromas, so some people age stouts, bocks and porters on purpose to develop those. Same for bottle-conditioned beers, which have live yeast that’s still fermenting. But beers with delicate flavors, like pale ales and pilsners, are generally better fresh.

‘Swapping it out’

The thought of old beer lingering on store shelves drives brewers crazy.

Because while ale that’s been on the shelves too long won’t kill you, it might seriously disappoint your tastebuds. If you haven’t had a particular beer before and the first time you try it, it’s not very good, you might just end up dismissing the brewery altogether.

“We’re one of those breweries where if we see beer that’s old we’ll credit it and swap it out for something fresh,’ says Luke Bowen, co-founder of Evil Genius Brewing Co. “It’s more valuable for us to have a customer buy a fresh beer and have a good experience then lose a little bit on swapping out.”

Swapping beer out — and the practice of putting “best by” dates on beer in the first place — was pioneered by Sam Adams. Headquartered in Boston, the brewery produces nearly a third of its beer at a facility in Allentown, Pa.

“Freshness is an important ingredient in beer, just like hops and malt,” says head brewer Jennifer Glanville. “Whether it means checking freshness on kegs in a pub basement or checking the shelves at a grocery store, we’re constantly, almost obsessively, checking our beers to ensure they’re fresh.”

Who’s responsible?

It’s not entirely clear where the responsibility lies for making sure customers don’t end up with old beer. After beer leaves the brewery, it ends up in the hands of a distributor. The distributor then decides when to deliver it to actual stores, whose managers then have to figure out how to manage inventory and what to put on shelves.

Why were there multiple boxes of Victory Anniversary Ale with an “enjoy by” date of June 4 on the sale floor at Springfield Beverage on Washington Avenue last week?

In this case, the fault probably lies with the store itself. Unlike The Beer Peddlers and two other case stores that were checked, Springfield Beverage is in Four Seasons Food Court territory when it comes to having tons of old beer in stock. A box of Deschutes Red Chair NWPA had a best-by date of April 9. Weyerbacher Merry Monks (which could arguably be ok when aged) had a best-by date of June 2. A 12-pack of Uinta Hop Nosh had a stamp that said it was best before August 5.

On a recent morning, employees at Four Seasons Food Court didn’t want to discuss the old beer issue at all. The manager, who went by Jim and whom we had spent days trying to pin down, wouldn’t talk specifics. He said a “company” comes in to restock sometimes, and that it’s “like a one-time thing” that he and his co-workers didn’t deal with at all.

There was also another employee in the store at the time, crouched by the refrigerator with a notepad. He appeared to be taking inventory — of the Four Seasons’ beer selection.