There are the cheeseburgers, of course. And the Billy Goat Tavern’s weathered, subterranean charm. But beer, funny enough, was never a reason to step below Michigan Avenue into Chicago’s most iconic bar, where, until recently, the same three beers have been on draft for the past 20 years.

Schlitz.

Billy Goat Lager.

Billy Goat Dark.

End of story — and the reason that Billy Goat has always been one of the few places I’ve defaulted to an icy bottle of Old Style. (And, after enough Old Style, bourbon.)

All that changes now. Modern beer tastes and a bid to amplify its brand have compelled the family-run Billy Goat to get with the times. The times have arrived in the form of Billy Goat IPA and Billy Goat Pilsner, both of which are made by local Baderbrau Brewing.

The underwhelming Billy Goat Lager and Billy Goat Dark, which were Berghoff Brewery brands made under contract by Stevens Point Brewery in Wisconsin, are being phased out.

“We wanted to bring our beer up a little bit,” said Billy Goat co-owner Bill Sianis, whose great-uncle, William Sianis, founded the tavern in 1934 where the United Center now stands.

Indeed, the two new offerings, released in November, are quality beers that will quite likely spell the end of my Old Style drinking at Billy Goat. (Though I’m not giving up the bourbon so easily.)

Billy Goat IPA is bright, clean and refreshing, rife with notes of grapefruit and tropical fruit. In a room where you’re likely eating a greasy double cheeseburger and ordering multiple beers, it dries out nicely. It’s drinkable on repeat. The Pilsner is similarly accessible: crisp and lean, lightly sweet, grassy and bready.

If they taste familiar, they should.

Billy Goat Pilsner is simply a repackaged version of Baderbrau’s flagship, Chicago Pilsener. The IPA is a repackaged version of Baderbrau’s hop-forward Lawnmower Lager, a summer seasonal release since 2014. That’s right: Billy Goat IPA isn’t even an India pale ale. It’s an IPL: India pale lager.

Sianis and Baderbrau founder Rob Sama agreed that calling it an IPA was a simpler way to communicate with customers who are interested in a hop-forward beer.

“Ease of understanding,” Sama said.

The project began as an effort from the Sianis family to capitalize on the Billy Goat name, which got a boost from “Saturday Night Live” in 1978 that no money could buy (“Cheezborger, Cheezborger, Cheezborger … no Coke, Pepsi; no fries, chips.”)

Billy Goat hired local licensing outfit JRL Group in 2016 to figure out how to broaden the reach of the brand. In April, they started with the obvious: frozen hamburgers — the same ones served at Billy Goat, which are made by Elk Grove Village-based Devanco Foods. Next, they addressed the second-most crucial feature of a Billy Goat visit: beer. (Could potato chips be far behind? Sianis acknowledged it makes sense.)

Sianis and his family met this summer with Sama, whose tasting and PowerPoint presentation included a 21st-century tweak to Billy Goat’s beer approach: Rather than lager and dark, it needed a Pilsner (which is a type of lager) and a hop-forward beer.

“In today’s market, you’ve got to be hoppy and nonhoppy,” Sama said. “At Billy Goat, you have to have a Pilsner for Joe Sixpack, but eventually he might like the IPA.”

Sianis said he isn’t much of a hoppy beer drinker, but he liked the lean approachability of Lawnmower Lager. That told him it would translate for his mainstream audience.

“If you want to have more than one, this is good,” Sianis said.

“And that’s your goal when you’re sitting at the bar at Billy Goat,” Sama said.

Both Pilsner and IPA are on tap at Billy Goat’s nine locations (eight in Chicago, one in Washington) and available in six-packs exclusively (for now) at Jewel-Osco supermarkets.

Ultimately it’s the canned version of the beer that will move the most volume, and the package trades heavily on the Billy Goat affiliation. The words “World Famous Billy Goat Tavern & Grill” are prominent, along with the bar’s logo. Only on the side, in small print below the words “Cheezborger, Cheezborger, Cheezborger, No Fries, Cheeps!” is it indicated who actually makes the beer.

Anthony Suggs, vice-president of merchandising and marketing at Jewel-Osco, said the Billy Goat brand has quickly become one of the chain’s most popular, joining the likes of Revolution and Lagunitas.

Thanks mostly to the novelty of the brand, the beers have appealed both to seasoned and less experienced beer drinkers, Suggs said. He declined to say whether the IPA or Pilsner has sold better.

“It’s a unique time where craft beer is on fire,” Suggs said. “There’s a lot of variety out there and people looking to try the next thing. This is an easy one for them to try, especially being local. Knowing it’s local is an entry point for people.”

Baderbrau launched in 2012, but the Billy Goat beers are poised to become the brewery’s biggest hit. When Sama heard from irate retailers who also wanted the beer once it was available at Jewel-Osco, he suspected he had a hit. Distribution will expand to other grocery and beer stores in the coming months.

“Honestly, I was a little skeptical at first,” Sama said. “I’ve always enjoyed Billy Goat burgers and the experience, but I wasn’t so sure how that would translate into sales at retail. But I took a harder look at what happened with the burgers and realized there could be potential.”

Sama suspects the beer is reaching a new audience for Baderbrau: the most casual craft beer drinkers. He knows those customers are probably buying it due to the Billy Goat affiliation, but he’s OK with that. If early trends hold up, the Billy Goat partnership could double Baderbrau’s production in 2018, up to about 7,000 barrels of beer.

“It’s a little shocking to see how people have reacted,” Sama said. “We’ve been around for a while, and we’ve never had retailers saying, ‘We have to have this.’ When they were saying that, I knew we were on to something hot.”

But there may be no place where Billy Goat’s new beers are more welcome than at Billy Goat itself. The bar is gloriously stuck in time and priced like it: The Cheezborger Original costs $3.35, a bag of chips is just a buck and the beers are a very reasonable (especially for downtown) $4 for a 14-ounce pour.

The upgrade they provide over Billy Goat Lager and Billy Goat Dark is immeasurable. At the release party for the Baderbrau beers in November, there was still a bit of Billy Goat Dark left on tap. I tried it for the first time in years, and it was as forgettable as I remembered: thin and watery with a brief, unwelcome burst of caramel sweetness and wholly lacking aroma. It tasted like 1990s beer drinking. I wasn’t alone in the assessment.

“In my heart of hearts, I never really liked it,” said David Bagger, 34, a teacher in the suburbs who counts himself as a once-a-week Billy Goat regular. “I was here for the bottles of High Life and shots of Malort.”

He was drinking Billy Goat IPA at the time. He said he would quite gladly come back for more.