Keurig Green Mountain last year sold more than 9 billion of its traditional single-serve plastic coffee pods — or K-Cups. Zero could be easily recycled.

This inconvenient fact has provoked a decade of hand-wringing within the company and discontent among consumers. Placed end to end, the pods sold in a year would circle the globe roughly 10 times. Concerns among environmentalists are mounting, and sales growth is slowing.

Now Keurig says it has found a solution. In the coming months, the company will begin to sell K-Cups made of material that is easily recycled.

The new K-Cup, composed of polypropylene, gives Keurig an answer to critics who say the company has shown a flagrant disregard for the planet’s well-being. Like common plastic bottles, the new K-Cups can be sorted and shredded by middlemen and sold to manufacturers that use recycled plastic.

But the new K-Cups are unlikely to put an end to the attacks. The new cups are not compostable. They are not reusable. And Keurig will still be selling billions of pieces of plastic each year.

The company says it is trying its best. “When you look at the trends toward single-serve generally, you can either villainize it, or you can fix it,’’ said Monique Oxender, Keurig’s chief sustainability officer. “We’re trying to fix it.’’

How the K-Cup became ubiquitous is something of a fluke. Company lore has it that in the mid-1990s, when the Keurig founders were looking for a container they could use for the single-serve coffee machine they were designing, they came upon an unlikely candidate: the takeout salad dressing containers from a local restaurant, Ken’s Steakhouse.

Keurig began buying the containers in bulk. But because Keurig machines were designed specifically for the pods, changing course soon seemed virtually impossible.

In 2006, Green Mountain Coffee Roasters, a Vermont chain that emphasized social responsibility, acquired Keurig. The environmental implications of the single-serve model were soon a cause for concern.

In the intervening decade, Keurig tried to design various replacements for the traditional K-Cup, but it proved devilishly difficult to redesign.

A few years ago, engineers at Keurig found that by using polypropylene instead of the previous plastic blend, and injection molding instead of thermoforming, they created a K-Cup with all the right features.

Keurig says it will start selling these recyclable K-Cups later this year. The new cups will make up half of its supply by 2018, it says, and all by 2020.