Some 2,000 people turned out for the inaugural North American Organic Brewers Festival in 2003. The first of its kind in the U.S., the festival, held in Portland, Oregon, spotlighted organic beers from 25 breweries. By August 2015, the event, by then known simply as Organic Beer Fest, had grown considerably in size and scope, drawing 12,000 people to sample from 36 breweries. This August, organizers say 45 breweries will participate.

Such is the growth in popularity in the U.S. of organic beer, which carries on despite some considerable challenges.

In the late 1990s, there were perhaps only two American breweries producing at least one organic beer brand — the Lakefront Brewing Co. in Milwaukee and Eel River Brewing Co. in Northern California. Now there are dozens in several states, most in California and the Pacific Northwest.

U.S. organic beer sales have increased more than tenfold since 2003, from $9 million to $92 million in 2014, the latest year figures were available from the Organic Trade Association (which is expected to release its 2015 numbers imminently). That 2003 starting date is significant: Federal legislation enacted the year before standardized organic requirements nationwide; before then, states and private agencies were using all sorts of guidelines to certify.

So what, exactly, are organic beers?

A beer can be called “organic” if it meets the following federal guidelines:

At least 95 percent of its ingredients are organically produced (e.g., no GMOs, synthetic fertilizers, pesticides).

The brewery must prove that the remaining ingredients were not available in sufficient quantities or qualities in organic form.

And these non-organic ingredients must be on the federal Agriculture Department’s list of allowed and prohibited substances.

There is also a kind of super-duper organic certification, called 100 Percent Organic, that means exactly what it says: Everything that went into the product, including cleaning and processing materials, was organic. Such beers are understandably rare.

Finally, there is “Made With Organic…” This certification requires a lower threshold for organic ingredients: at least 70 percent, excluding salt and water.

“I wanted to create a beer that connected my healthy, active lifestyle with my social life, and bring it all together.” —Smart Beer founder Gabriel Heymann

Most organically labeled beers in the U.S. are comprised of ingredients that are at least 95 percent organic. The majority of entrants in the Organic Beer Fest, for instance, fall under this certification, which is usually denoted on packaging with that round “USDA Organic” label.

As for that 5 percent or so sliver of non-organic ingredients, those usually come from non-agricultural products, such as yeast, Irish moss (for clarity), and calcium sulfate (for adjusting the mineral content of water). Until January 2013, hops were among the likeliest non-organic ingredients in organic beer because some varieties were simply difficult to cultivate organically. Now, regulations mandate that only organically grown hops can be used in organically labeled beer.

The move, which involved a two-year transition beginning in late 2010, was a kind of watershed in organic brewing. Brewers already using organic hops praised the regulatory change as a way of leveling the playing field. Brewers had been able to label their beers “organic” without using such hops, so long as they met the 95 percent threshold with other ingredients. To some brewers, that seemed ridiculous given the centrality of hops in brewing, especially in ever-bitterer American craft brewing.

The changeover to solely organic hops did increase costs that much more for organic brewers, however. Organic hops can cost several more dollars per pound than conventional ones, if not twice as much more, depending on the variety. Like with any finished organic product — fruit, coffee, baby food — organic ingredients that go into organic beers are just generally more expensive than their conventional counterparts.

Regardless, brewers must often price their organic beers competitively with beers from more conventional ingredients or risk losing — or never gaining — customers. This drives up the cost even more, not allowing organic producers to make up too much of the difference on the sale.

For some brewers, the cost is worth it.

They cite concern for the environment — organic products require fewer possible contaminants, such as pesticides, and less-invasive farming techniques. Others might cite the assumed health benefits of a foodstuff created this way (though the alcohol from two or three beers might dispatch those gains pretty quickly). And for some brewers, organic beer fits tastily within a lifestyle already keen on organic everything.

Or it might just be a combination of all three.

Gabriel Heymann was a touring musician and a yoga instructor in 2015, when he launched Smart Beer, the first organic brewing company in New York state. Based in New Paltz, about a 90-minute drive north of New York City, it now brews a golden ale and an India pale ale under contract at the Olde Saratoga Brewing Co. farther up the Hudson.

“I wanted to create a beer that connected my healthy, active lifestyle with my social life and bring it all together,” says Heymann.

Organic brewing presented challenges to this ethos, beyond the cost. For one thing, sourcing the ingredients is more time-consuming and difficult. The same goes for getting the necessary OKs to slap that round label on bottles and cans. Breweries in general already navigate a warren of regulations to get started. Organic brewers must go that much further — plus accommodate regular inspections, sometimes surprise ones, to check if they are maintaining standards.

“One certification is difficult enough,” Heymann says. “When you start layering government agencies on top of each other, you have to put a longer timeline together in terms of getting your labeling ready, getting the product certified, all those things.”

For some, the exertions have proved too much. Craig Nicholls founded a Portland brewpub dedicated to organic brewing shortly after he founded the Organic Beer Fest. The festival continues, but the brewpub closed abruptly in 2010, buckling under expenses and unable to find a buyer.

The corporate parent of Wolaver’s Fine Organic Ales, a Vermont outfit dating to 1997 and one of the oldest organic labels east of the Mississippi, stopped making the beers at the end of 2015. “[T]he rising cost and availability of organic ingredients has made it increasingly challenging to create an affordable product,” Wolaver’s explained in a public message.

In the end, does the taste, that all-important measure, justify such effort and cost? Organic beers may taste and smell fresher than beers with more conventional ingredients. That’s in the palate of the beholder, though, and there’s only one way to find out.

Here are a few organic beers to start your journey of discovery:

Peak Organic Brewing Co. Summer Session Ale

5 percent alcohol by volume; 61 international bittering units

This relatively low-alcohol fare from Portland, Maine, is thin-tasting and mildly bitter. An inoffensive, easily quaffable selection for the summer months.

Peak Organic Brewing Co. Super Fresh Cut

7.6 percent ABV; no IBUs given

A magnificent beer — dense and rich-tasting, especially for a pilsner. There is a slightly tangy finish, and it’s smooth enough to be sessionable, whatever the ABV percentage.

Peak Organic Brewing Co. Fresh Cut

4.6 percent ABV; no IBUs given

This is the milder, drier—and, frankly, disappointingly bland — kid brother to Peak’s Super Fresh Cut pilsner in terms of strength and density.

Uinta Brewing Co. Baba Black Lager

4 percent ABV; 32 IBUs

This schwarzbier from Salt Lake City is roast-y all the way through, from the aroma just after the pour to the aftertaste. Drily bitter and full, Uinta’s organic release should be perfect for the colder months.

Samuel Smith’s Old Brewery Organic Chocolate Stout

5 percent ABV; no IBUs given

An exceedingly smooth and yet chocolaty rich concoction out of the renowned Yorkshire brewery in England. This stout also thankfully lacks that burnt taste (and sometimes smell) that other chocolate numbers have — a real treat, a dessert beer.

St. Peter’s Brewery Co. Organic English Ale

4.5 percent ABV; no IBUs given

A lightly roasted maltiness comes through in this selection from a brewery in Suffolk, England. There’s a dry, sweet finish, too — a solidly unadorned, straightforward beer. And the flask-shaped bottle is really cool.

Tom Acitelli is the author of The Audacity of Hops: The History of America’s Craft Beer Revolution. His latest, American Wine: A Coming-of-Age Story, was a finalist for the 2016 James Beard Award for best beverage book.