Drinking beer might not be the best for your health, but Carlsberg is out to prove it can be better for the environment.

The Dutch beermaker says they’ve created the first paper beer bottle, made from sustainable wood fiber with a coated interior to prevent seepage.

Two prototypes are in the works for their Green Fiber Bottle: one with a thin layer of a recyclable polyethylene terephthalate (PET) plastic in the interior, and the other using instead a polyethylene furanoate (PEF) polymer film that is 100-percent biobased, meaning it’s made from natural, biodegradable sources.

Carlsberg hopes to create a bottle made from 100% organic materials without polymers — part of their overarching plan to achieve zero carbon emissions at its breweries by 2030.

“While we are not completely there yet, the two prototypes are an important step towards realizing our ultimate ambition of bringing this breakthrough to market,” said Myriam Shingleton, the company’s vice president of development. “Innovation takes time and we will continue to collaborate with leading experts in order to overcome remaining technical challenges, just as we did with our plastic reducing Snap Pack [plastic-free beer can packaging].”

She also added that paper was preferable to aluminium or glass because it’s sustainably sourced and has a “very low impact on the production process.”

Carlsberg has been working on the model since 2015 with tech firm ecoXpac and researchers at Danish Technical University, and it produced the test bottles with help from packaging company BillerudKorsnäs. The Denmark-based brewer is one among a number of consumer brands, including Absolut and L’Oréal, who call themselves part of Paboco, or the “paper bottle community,” according to an announcement made at the C40 World Mayor Summit in Copenhagen.