BALTIMORE – What do we mean when we talk about cider? It seems pretty straightforward: Cider is the fermented juice of crushed apples. Of course, things immediately get complicated in the United States, because we often have to clarify we’re talking about hard cider, to distinguish it from the soft drink we buy at the farmers market for the family. But once we’ve established that we’re talking about the alcoholic beverage, it should be easy enough to define, right?

After spending several days here at the eighth annual CiderCon, along with more than 1,000 other cider enthusiasts and makers, I’m not so sure.

Defining “cider” - and creating a language to talk about it - is very much on the agenda of the U.S. Association of Cider Makers, the trade group of more than 1,000 members that puts on CiderCon. Recently, the association released a new “Cider Style Guide” that delineates several categories of cider (including spiced, hopped, pear and other non-apple ciders). Most notably, there are now “modern” ciders, which are made from dessert apples commonly found in supermarkets, such as McIntosh, Jonagold, Gala or Granny Smith. And then there are “heritage” ciders that have “increased complexity” and “complex aromatics.” Most significantly, heritage ciders use traditional bittersweet or bittersharp cider apples, older heirloom varieties or perhaps even crab apples or foraged wild varieties.

Cider has always found itself betwixt and between. Some cidermakers have followed craft beer as their model, selling cider mostly in cans or on tap, with lots of experimentation, clever branding and nontraditional flavors. Others have followed the wine path, with close attention to apple varieties, orchard practices and fermentation techniques, and sell their ciders in 750-milliliter bottles. The cider association’s style guide now formally recognizes this profound divide in approach.

“We had to find a way to organize the messy world of cider,” said Eric West, publisher of Cider Guide, who helped create the style guide.

“We hear consumers say, ‘I’ve had a cider. I don’t like cider.’ But they don’t realize how vast the category is,” said Michelle McGrath, the association’s executive director. “You can have a hopped apricot cider made from dessert apples, and you can have a bone-dry sparkling cider made from cider or heirloom varieties. People value a wine grape, and we’re trying to get people to value a cider apple.”

The presenters at CiderCon danced cautiously around the modern vs. heritage cider issue. It came up during a training session for the recently introduced Certified Cider Professional exam (yes, cider is now developing the equivalent of a certified sommelier for wine or Cicerone for beer). “We use the word ‘complex’ a lot. But I don’t want to make this a value judgment,” said Brian Rutzen, beverage director at the Northman in Chicago who advises the certification program. “We want to have a big tent.”

It’s clearly a big tent. At a recent gathering, 50 producers were pouring their ciders at an event called Cider Share, and I tasted dozens. There were certainly heritage producers on hand, established cidermakers such as Black Diamond from New York’s Finger Lakes, next to upstart heritage producers such as Milk & Honey or Keepsake from Minnesota and Anxo in Washington.

But, by and large, the modern style of cider reigned. I tasted lots of hopped ciders, ciders spiced with ginger or pepper, or flavored with black currant, tart cherry or raspberry - all falling into the association’s categories. Some producers, such as Tandem Ciders from northern Michigan, made both modern and heritage - a delicious 100 percent McIntosh bottling poured next to one that used mostly the heirloom Rhode Island Greening variety.

At the table of Noble Cider, from Asheville, North Carolina, I chatted with cidermaker Trevor Baker, an association board member who identifies as a modern cider producer. Among his flavored offerings, Baker poured me a surprising cranberry- orange cider, spiced with habanero pepper. I didn’t know quite what to say after tasting that. I certainly could not discern an apple.

A cider blogger (yes, cider blogs are now a thing, too) whom I recognized from an earlier session approached Noble’s table, and Baker shouted, “How’d you like to taste a hopped peach cider?”

“Hell, yes,” she said. “I love ciders with stone fruit.”

Contrast that with a session I attended on Thursday called “Champagne Method Cider,” where I experienced several mind-blowing sparkling ciders made by Eden Specialty Ciders in Vermont, Snowdrift Cider in Washington state and two cidermakers from New York’s Finger Lakes, Eve’s Cidery and Redbyrd Orchard Cider. What we tasted was every bit as complex as fine wine, with the same attention paid to the apples as a winemaker would to the grapes. Such varieties as Kingston Black, Yarlington Mill, Dabinett, Somerset Redstreak and even foraged wild crab apples were discussed with the same reverence as pinot noir or nebbiolo.

Questions from the audience about aging on the lees, the use of barrels and malolactic fermentation made it feel more like a wine event. Tim Larsen, from Snowdrift, even co-opted an old winemaking cliche: “Cidermaking, as everyone here agrees, begins in the orchard.”

“Making cider this way is very expensive,” said Autumn Stoscheck of Eve’s Cidery. “But when you can buy a traditional-method sparkling cider made from beautiful fruit like this for under $20, that’s a great value.” It’s true that few sparkling wines would rival, say, Redbyrd’s $27 Celeste Sur Lie, bone dry with a creaminess balanced by elegant tannins and razor-sharp acidity.

Yet the sparkling ciders poured in this session come from tiny production runs: fewer than 400 cases a year, and fewer than 100 for the Redbyrd. “Who is this for, and how do you market it?” said Eden cidermaker Eleanor Léger, repeating a question from the moderator. “My first thought is: ‘I have no effing clue.’”

Right now, 75 percent of cider in the United States is produced by large brands owned by huge beverage companies, such as Angry Orchard, Strongbow, Woodchuck, Crispin and Stella Artois Cidre. But the real growth has recently come from smaller producers: Regional and local cidermakers saw a 30 percent spike in sales last year, after jumping 40 percent in 2016.

With so many swirling and competing visions of cider, between modern and heritage, big and small, it’s no surprise that confusion occasionally rises. During a session titled “Wild Fermentation and Other Heritage Cider Options,” we tasted ciders from hip, in-the-know producers such as Hudson Valley’s Sundstrom, as well as experimental bottlings from Angry Orchard’s Innovation Cider House. “Cidermaking is all about choices,” we were told by Tom Oliver, a legendary cidermaker from Herefordshire, England, renowned for his wild, pungent, complex ciders.

An apple grower from Tyro, Va., named Adam Cooke, stood up and expressed genuine confusion. “I’m at the point where I can plant 20 acres of bittersweet apple varieties,” Cooke said. “But what I want to know: Is this just a passing trend? Will there be a demand in 10 years?”

Ryan Burk, the cidermaker at Angry Orchard, admonished him by saying: “Be part of what makes it happen. There’s a different market for Concord grapes and pinot noir.”

I caught up with Sam Fitz, owner of Anxo, which has been very popular since it opened in Washington. Even though Fitz is new to the scene, he has been elected, during CiderCon, to the association board. He says the future of cider lies in the larger apple growers investing in cider and heirloom apple varieties and cideries moving away from using dessert apples. “We have to get back to cider apples, heirloom apples,” he said. “How many Anxos can exist? There just aren’t that many cider apples available.”

“The industry is still trying to figure itself out,” said Fitz. “We don’t really know who our market is.” We tasted some of Anxo’s Cidre Blanc. It is most definitely a heritage cider. But it’s also served in a can.

“It’s all up in the air right now,” Fitz said. “But whatever cider is going to become, it is being decided right now.”