In June, Peet's Coffee & Tea dispatched a truck emblazoned with the motto, "Proof in Every Single Cup," to drive across the country. Every few days the mobile cafe pulls up to the sidewalk of a different city, and the baristas on board hawk free cups of the company's new single-serve coffees. They set out tables and chairs, place sandwich board advertisements along the sidewalk, give out orange-rimmed sunglasses, and take photos of smiling customers clutching Peet's cups.

The mobile cafe is part of a nationwide campaign Peet's launched this summer in its effort to crack the hottest sector of the coffee business: single-cup brewing. And Peet's is actually late getting into the single-serve market; Starbucks and other coffee giants moved in early and are now reaping huge profits.

"It's growing like crazy," said Joe DeRupo, spokesman for the National Coffee Association. "It seems like virtually everyone is jumping on the single-serve bandwagon."

For the unfamiliar, single-cup coffee comes in individual portions, encased in plastic capsules or packets that you put in a special coffeemaker to brew one cup at a time. It's the polar opposite of the pour-over artisanal coffee that's so popular in much of the East Bay, but tens of millions of consumers have already switched to single-cup brewing nationwide, likely because it's ultra-convenient.

DeRupo's group recently published a report that found that 12 percent of US households now have a single-cup brewer. A February poll by Harris Interactive found that one in three Americans either have a single-cup brewer at home or at work. The market nearly doubled in the last year, climbing to almost $2 billion in sales, according to a report released last month by market research firm Packaged Facts. Sales are projected to reach $5 billion by 2016.

Peet's wants to carve out a niche in the wildly profitable single-cup market by trying to preserve the coffee craftsmanship founder Alfred Peet introduced to American consumers nearly half a century ago in North Berkeley. Peet's officials said they spent five years developing their single-cup product. On the company's website, a letter addressed "Dear Loyal Peet's Fan" from roastmaster Doug Welsh explains the rigor: "We've designed a specific dose (to the tenth of a gram) for each specific blend and a grind parameter that we measure to the micron."

But even if Peet's succeeds in convincing customers that it hasn't ditched quality to make single-cup coffee, the company's entrance into the market and the explosive growth of pod coffee overall includes an often-overlooked dark side: It creates a huge amount of waste. In fact, it's already producing hundreds of millions of pounds of unrecyclable trash for the nation's landfills each year.

The popularity of single-cup brewing also represents a striking contradiction for consumers at a time when more and more people recycle their waste diligently each day and are increasingly aware of their environmental footprint. "It's the poster-child dilemma of the American economy," said James Ewell, a packaging specialist who's consulted with major coffee companies. "People want convenience, even if it's not sustainable."

The basics of coffee-making have changed little during the past millennium. We're still using hot water to release flavor from ground beans, but we've found increasingly complex tools to help us do it. Until recently, two innovations had shaped how most Americans brew over the last century: the percolator and its electric descendent, and the automatic drip coffee-maker. With each we delegated more responsibility to our appliances, and now we've arrived at a system — single-cup brewing — that asks almost nothing of us.

The coffee comes sealed in pods and pouches, shelf-stable until it's plucked from the cupboard and popped into a machine that coaxes a personal cup from it in seconds. Afterward, the spent capsule gets tossed in the trash. No preparation. No cleanup.

Single-cup brewing took off in Europe in the early 2000s, when brands like Nespresso popularized their ultra-efficient espresso machines. The trend didn't take off in the United States until the mid-Aughts, when engineers found a way to tweak the technology for domestic tastes. John Sylvan, who started Keurig — now the biggest name in American single-cup coffee — spent years hand-making prototypes before he created a working system that made American-style coffee. Single-cup brewers first gained traction in offices and hotels; more recently they've become fashionable gifts.

Industry experts say it isn't just the utility of the machines that's galvanized consumers. Single-cup systems offer a near-irresistible trifecta: convenience, consistency, and variety. As the brewers claim space on ever more countertops, the fleet of single-cup beverages keeps growing. Keurig alone boasts more than 30 brands and 250 "K-Cup Pack" flavors, including raspberry chocolate truffle coffee, Snapple lemon iced tea, and acaí berry "fruit brew."

The coffee is often marketed as "premium," and the machines as status symbols for discerning consumers — but aficionados question the quality of the brews. In his book The Blue Bottle Craft of Coffee, Blue Bottle founder James Freeman railed against single-serve coffee. In a passage dubbed "A Special Place in Hell: Pod Coffee," he blasted producers for hijacking the trappings of excellence while delivering a craft-less cup. "Pod coffee is bad and wrong," he wrote. "[I]t teases people into an industrially produced product masquerading as handcrafted." After figuring out the brewing ratios and extraction times of two popular pod brewers, he concluded that it's simply impossible for them to make a truly tasty beverage.

Whether it's delicious or not, single-cup coffee is expensive. In fact, pound-for-pound, it costs consumers far more than the finest artisanal coffee available in the Bay Area. A 24-pack of Folgers Gourmet Selections K-Cup, for example, typically retails for $16.49. The capsules each hold roughly 8 grams of coffee, which means that the 24-pack works out to about $39 a pound. A 24-pack of Starbucks House Blend typically costs $22.49, or about $53 a pound. By contrast, the same Starbucks roast costs just $12 a pound when sold in a single bag. An artisanal bean, like Four Barrel Coffee's Kenya Gatomboya, a shade-grown coffee from a 700-member cooperative, costs $18 for a 12-ounce bag, or about $24 a pound.

But as expensive as single-cup coffee is for consumers, the costs to the environment are even higher.

As consumers replace bags of ground coffee in their pantries with boxes of disposable pods, the amount of packaging waste associated with coffee-making has swelled exponentially. "We can get to a cup of coffee dozens of different ways," said Martin Bourque, director of the Ecology Center in Berkeley. "The best way is a large volume of coffee that goes into a cup that's washed and re-used a thousand times, and the coffee goes to compost or mushroom production. That's best-case scenario," he said. "The worst-case scenario is these pods."

Some single-serve coffee systems use plastic pouches, while others use aluminum pods, but most, including the popular Keurig K-Cup system, rely on plastic capsules. This is the kind Peet's opted for. They're miniature, disposable drip brewers: A plastic mesh filter basket filled with coffee grounds enclosed in a plastic cup and sealed with a plastic-and-foil lid. The single-cup machines then pierce the lid and the bottom of the capsule and flush hot water through to produce a cup of coffee.

"The challenge presented by these single-cup pods is the fact that you have a multi-material item," explained Tom Padilla, recycling coordinator for StopWaste.org, the agency tasked with creating a sound waste management and recycling program for Alameda County. Even if the capsule components were individually recyclable, he said, they're impossible to process because they're fused together.

"They were designed to be trash from the outset," said Rebecca Jewell, recycling program manager for Waste Management's San Leandro facility. Hopeful consumers continually toss them in the recycling bin, she said, but they end up in a landfill anyway.

Coffee companies are well aware of the problem. The second brewing system Keurig introduced, the Vue system, tried to address the issue of recyclability in what the company called "an incremental step on our environmental journey." The system doesn't work with the original K-Cup packs, which are made from number seven plastic, a blended plastic that's nearly impossible to recycle. Instead, the Vue capsules use a plastic cup made from polypropylene, number five plastic, and users can peel the foil lid and filter away from the cup.

The cups are then recyclable — in theory. The problem is the cups are too small to be captured in most recycling facilities where machinery separates objects by size and density, said Mark Oldfield, assistant director of public affairs for California's Department of Resources Recycling and Recovery. Most facilities filter out items under two-inches in diameter. In any case, number five plastic is rarely recycled in California, Oldfield said. "It's very difficult to deal with something like that," he added. "It's something where convenience is trumping our typical mantra of reducing and recycling."

At the Davis Street Transfer Station, where Jewell works, half of Oakland's trash and recycling is processed. Some 750,000 tons of garbage move through the facility every year. The trucks that empty our trash cans dump their loads here, into a pit, nine-feet deep with trash, where a dozer churns it up before semi-trucks take it to the Altamont Landfill.

Our recyclables end up at Davis Street, too. They enter the sorting facility through a chute, dropping onto a vibrating sifter — a metal platform punched full of holes — and as they bounce across it, the small items fall through. Everything else jostles along into a sorting system of chutes, magnets, and blowers that empties onto conveyor belts, where workers clad in goggles, dust masks, and needle-proof gloves winnow out valuable materials.

Outside the city-block-size building that houses the sorting apparatus, the small objects sifted out of the recycling form a mini mountain range. The coffee pods from our recycling bins land here, amid bottle caps, pill bottles, marbles, plastic dolls, and the spent limes from countless Coronas. "We are always trying to capture the little objects in the hope of finding glass," Jewell said.

Mixed in with all the junk here are shards — valuable because California's wine industry keeps the market for recycled glass strong, Jewell explained. The small pieces of debris, including the single-cup pods, get shipped to a glass-recycling facility, where they're separated from the glass using magnets and float baths and then sent to a landfill.

So while coffee companies tout the energy-efficiency of single-cup brewers and trumpet their solution to wasted coffee, their organic and fair trade pods pile up in landfills by the billions. "Even though they're little, they add up," noted Darby Hoover, a senior resource specialist with the Natural Resources Defense Council.

There's a dearth of data available on the amount of waste generated by single-serve brewing systems, but a little back-of-the-envelope arithmetic offers a crude — and eye-popping — estimate: The US Census Bureau puts the total US population at around 316 million, so if one-third of us are using single-cup brewers at home or at work, that's more than 100 million single-serve coffee packages a day or 36.5 billion a year. (Keep in mind, that may be a conservative estimate because it assumes that each person only makes one cup of single brew a day.) If the capsules weigh roughly 12 grams (like Peet's pods), that's 438 billion grams of single-cup coffee packaging used annually, or about 966 million pounds of waste. That's the equivalent of throwing away about 150,000 Hummer H2s each year.

"We're filling up our landfills with materials we should be using more wisely," Hoover said. "It's a trend of dissociating more and more from the consequences of using a product. Landfills represent our misconception of 'away.' What we mean is that they disappear from our daily lives and we don't have to think about them any more. Away is not something that is going to work long-term. Eventually we're going to fill up that pit in the ground and then another one and then another one."

Environmentalists also voice concerns about the impact of landfills through groundwater contamination and air pollution, as methane, a powerful greenhouse gas, is released from decomposing material. Single-cup pods waste resources, too: When non-renewable source materials end up in landfills, those materials are lost forever. The building blocks of plastics are derived from petroleum, and our main source of aluminum is bauxite ore — with a finite supply of these resources, environmentalists point out, it makes little sense to allocate them to products that will be used once and then end up in a sealed pit. The essential problem with single-cup pods, Hoover continued, is that they're an unsustainable way of delivering coffee to people.

They're the worst-case scenario.

But they're awfully good for business. Environmentalists who've been watching the industry say the thrust toward small, intricately packaged products like coffee capsules is a boon for companies in many ways. "They're emblematic of the way that packaging is headed in general," said Bourque.

He explained that plastic packaging proliferated with the rise of global distribution in the Eighties, and as the cost of transporting products went up and their ability to abide travel became more important, plastics quickly replaced heavier, breakable glass containers. Now, new plastic technologies allow companies to use packaging to their advantage in other ways. Blister packs — "the ones you always worry about hurting yourself with," as Bourque describes them — have great marketing value. "There's a lot of real estate for you to put your brand on," he said. Plus, they make it possible for little products to hang prominently in stores instead of sitting on the shelf tucked in among dozens of competitors.

Single-serve coffee also provides companies more surfaces to paint their brand logo on, but environmentalists say it's exemplary of a more troubling tendency. "There's a trend where producers of globalized products are looking for ways to package and sell very small amounts of product because they make a lot more money than selling in bulk," noted Christie Keith, international co-coordinator for GAIA, the Global Alliance for Incinerator Alternatives. This trend taps two sets of consumers: those with the luxury to pay for convenience, and those with means so limited they can only afford the smaller portions.

"The core of this question," Keith continued, "is when you're producing a lot of waste for a small quantity of product, who's suffering the consequences?"

Keith and her colleagues think we all are. They argue that at every stage of the process — from the public health costs of plastic resin manufacturing in Louisiana's "Cancer Alley" to the effects of long-distance product transport on air quality, to the cost of waste management services — we all pay the price. But is it worse for those of us who are already paying $50 a pound for coffee, or those of us who aren't?

The health effects of drinking something that's made by forcing scalding water through a flimsy plastic cup are unclear. A spokesperson for Keurig said the company uses only BPA-free plastics that have been approved by the FDA. One Keurig patent lists the K-Cup components as a blend of polyethylene, ethylene vinyl alcohol (EVOH), and polystyrene. These are all commonly used plastics, but there are known health issues associated with styrene. Styrene has been shown to migrate from containers into food or drinks and accumulate in our fatty tissue. Long-term exposure to small amounts of styrene has been linked to neurotoxic symptoms like fatigue, nervousness, and difficulty sleeping, plus low platelet counts and chromosomal and lymphatic abnormalities.

But Keith said that the way things work now, there's no incentive for corporations to take responsibility for the sustainability of their products. She supports extended producer responsibility laws, which hold corporations accountable for the costs of managing their products at the end of their life cycle, as one avenue for change. But large companies have historically opposed such laws, arguing that they'll be forced to raise product prices to defray the expense.

Hoover, however, noted that those costs aren't being created: Consumers will just see them at the store instead of on their garbage and recycling bills. And forcing producers to face those costs, she added, could make for saner packaging practices.

For all their micron measuring, Peet's product developers have failed to solve the environmental problems posed by single-cup coffee. In fact, the company hasn't publicly addressed the issue of sustainability surrounding its new product line since it launched. After repeated requests for an interview for this story, a spokesperson from Peet's' public relations company provided an email statement. It acknowledged the environmental challenges, emphasizing that they're an industry-wide dilemma, reminded me that the company's roasting facility in Alameda is Gold LEED certified, and evoked the chain's longstanding commitment to sustainable practices "from bean to cup."

Keurig's parent company, Green Mountain Coffee Roasters, is open about the need to find a more sustainable alternative to its current systems. The company offers a refillable cup, used with your own ground coffee, that solves the packaging waste problem completely. But it also negates the mess-free convenience of the pods. So far Green Mountain's next-best offer is a program for collecting used K-Cups from participating businesses. The cups are separated for composting and energy-from-waste processing, an incineration process that generates energy.

But for Keith and other environmentalists, energy-from-waste technology is just as problematic as landfilling. Noxious chemicals are inevitably released, they say, and building incineration infrastructure creates pressure to feed it. A Canadian company is offering another improvement — a mostly compostable capsule that works with Keurig machines. The capsules come in a plastic outer-wrap, though, and they're not compostable in all commercial facilities. "They're still 100 percent trash for us," Jewell said.

There's no real solution in sight, leading many to wonder how we could lack the foresight to get into such a conundrum in the first place. "Why are we creating a problem and then saying, 'What are the two bad options we're going to choose from?'" Keith said.

I recently spoke with Sylvan, the founder of Keurig. He hasn't been involved with the company since he was squeezed out in 1997, before Green Mountain bought it and made it a household name. I asked him if he'd thought about the environmental implications of the product while he was building the prototypes. "Not at all," he told me, on the phone from Boston. "There's nothing green about it."

He estimated that Keurig single-cup brewing machines produce ten times more solid waste than a single-cup serving made in a drip machine would. "People didn't think too much about that back then," he said, pausing a bit before he went on, "I feel kind of guilty. The world's changed in fifteen years." He told me he's proud he created something that's so well loved, but "hindsight's 20/20," he said. "I wouldn't do it now."

Today, Sylvan is working on a solar power company. He developed a technology that converts heat to power, and says he hopes it will change how people live — this time for the better. "I felt like I had to make a point of making something green," he said.

As for the future of single-cup coffee: "People will keep using them until what?" he chuckled, "hell freezes over?"

Correction: The original version of this story misstated how long humans have been brewing coffee.