If you’re looking for a sustainably produced wine at the bottle shop or grocery store, you’ll probably encounter an array of sustainability terms — organic, biodynamic, natural. It’s important to familiarize yourself with what these claims mean (and what certifications are available to corroborate them). But if you’re truly interested in buying sustainable wine, the intricacies of what happens in the vineyard can’t be the only considerations.

Although fertilizers, irrigation and pesticides all play a role in a bottle of wine’s overall sustainability, if it’s greenhouse gas emissions you’re focused on, don’t forget about the vessel it’s packaged in.

The problem of packaging

Sustainability certifications for wine generally don’t account for how the wine is packaged — let alone how far it then has to travel to get to its final destination. But according to a 2022 review of wine industry carbon emission studies, packaging is regularly cited as the top contributor to greenhouse gas emissions, often producing more emissions than grape cultivation and winemaking combined.

This outsized impact of packaging on a wine’s greenhouse gas emissions starts with the manufacturing of the material, which is almost always glass. Glass production involves a lot of heat: The material must reach around 1,700 degrees Celsius before it’s pliable enough to mold into a bottle. This heat, often created using natural gas — plus other emissions from the chemical reactions that occur in glassmaking — creates an estimated 86 million metric tons of carbon dioxide annually.

Total emissions from plastic production are much greater: 1.8 billion metric tons in 2019, according to the Organization for Economic Cooperation and Development. But glass production is significantly more energy-intensive, and a 2020 life cycle assessment of beverage packaging, published in Detritus Journal, found that “virgin” (unrecycled) glass bottles had the highest relative impact for eight of 11 indicators evaluated — including toxic outputs into land and freshwater systems, potential toxic impacts on humans, depletion of fossil fuels and Global Warming Potential, a measurement of greenhouse gas emissions — compared to other options like recycled glass, aluminum and certain types of plastic. (Packaging options other than glass and plastic were found to be the least impactful and the study also recommends a move toward reusable packaging.)

The emissions don’t end there: A product and its packaging are usually made in different places, so transportation is always a factor. While many U.S. winemakers use bottles manufactured on the West Coast, a large percentage are made in China — which means they must travel long distances to reach most of the world’s major wine regions. The bottles are heavy (around 500 to 600 grams), which means they often require more fuel to transport than other kinds of vessels, and they’re also easily breakable, necessitating additional packaging (and therefore, additional weight) to prevent them from shattering.

Experimenting with creative solutions

Some winemakers and packaging manufacturers say there’s a better way. At Protector Cellars, winemaker Alexander Katz packages his wines in aluminum cans — a trend that’s been growing in recent years. Katz chose to use aluminum partially because of its lighter weight (generally, wine in cans weighs nearly a third less than the equivalent amount of wine in a glass bottle) and durability, which means he has to use less protective material for shipping, but also because it’s more likely to be recycled: Though glass can essentially be recycled endlessly, 2018 data from the Environmental Protection Agency indicates only around a third of glass containers in the U.S. actually are, compared to around 50% for aluminum cans.

“There’s a lot of demand for aluminum because it can be very easily recycled back into a new aluminum can…so there’s a lot of incentive to do that,” Katz explains. “Glass, as a material, doesn’t have any value in the waste market.” While U.S. recycling facilities can usually make money recycling aluminum cans, recycling bottles often costs them.

Others in the industry, like the packaging company Packamama, are turning to recycled polyethylene terephthalate (PET). In addition to providing a good use for an abundant and otherwise wasted resource, Packamama CEO Santiago Navarro also wants to make an emissions argument for switching over. The authors of a 2019 article in the Journal of Cleaner Production found, when modeling supply chains for wine industry-standard .75 liter bottles, that producing even a new PET bottle created less than half the emissions of a glass bottle (though other packaging options, like pouches and cartons, had a much smaller footprint than both). Using recycled PET reduces emissions further. Still, there are drawbacks to relying on PET and EPA data suggests recycling rates for PET are no better than for glass.

“The wine industry will be more severely impacted by global warming than most,” says Navarro. “With one ton of raw material, we make just short of 16,000 bottles, and with glass, it would be just 2,000 bottles. Better raw material efficiency costs less and emits less to get it to the manufacturing site.” Packamama bottles also demonstrate the importance of weight and design: They weigh in at 63 grams, considerably lighter than industry-standard glass bottles and are flat to allow them to be more tightly packed, all of which cuts down on costs and emissions during transport.

“There’s a lot of demand for aluminum because it can be very easily recycled back into a new aluminum can…so there’s a lot of incentive to do that."

ALEXANDER KATZ

Winemaker, Protector Cellars

Still others are moving beyond traditional beverage packaging options entirely. One company, Frugalpac, is making “bottles” out of paper with wine contained in a plastic bag inside — a more aesthetically traditional take on bag-in-box wine. According to the company, an independent life cycle analysis by product-testing company Intertek determined that a Frugalpac bottle’s carbon footprint can be up to 84% smaller than a traditional glass bottle and a third smaller than a bottle made from 100% plastic. The 2019 Journal of Cleaner Production article identifies bag-in-box production as having the lowest emissions of all wine packaging options evaluated, though the bags typically end up as litter and the other materials can be difficult to separate for recycling.

So why aren’t all wine producers shifting to lower-emission packaging options? According to Katz, it partially comes down to tradition: “It is a very traditional industry, so [choosing a non-glass packaging option is] a little bit of a risk.”

Making glass better

In the wine industry, there are many practical reasons to choose glass. Although the vast majority of wines are meant to be consumed immediately — within a year or so — some wines are meant to age. Most winemakers agree that glass is, in fact, the best choice for wines that are meant to spend several years in the bottle before they’re enjoyed — plastic, for example, is more permeable for oxygen and leaches chemicals into the liquid over time. Since glass bottles are a non-negotiable for many producers, innovators are looking for better, more environmentally responsible ways to use them.

Oregon-based Revino is pioneering a model for reuse, distributing its easily refillable bottles to wineries in the Pacific Northwest and creating the infrastructure to collect, wash and recirculate them for up to 25 uses. Many participating wineries ship directly to consumers, who are encouraged to return the bottles through the Oregon Beverage Recycling Cooperative; they are given 10 cents for each bottle they return, though co-founder Adam Rack hopes they will be motivated mainly by the environmental benefit.

Working with refillable bottles, Rack notes, requires building buy-in from everyone: making the refilling process as simple as possible for producers, communicating to customers how these bottles differ from those they’re used to purchasing, encouraging participation in local wine economies. Community-building, he says, “is imperative to our mission and is the cornerstone of our business model.”

Until a fully circular wine economy gets off the ground, more sustainable glass packaging is a step in the right direction. Earlier this year, researchers at Pennsylvania State University filed a patent application for a new type of glass that — because of its lower melting point — can be produced with 30% less energy, lowering emissions significantly. In northern Italy, Alto Adige winery Castel Sallegg is exclusively using 100% recycled glass bottles made by Vetri Speciali, an improvement on the typical 50 to 60% recycled glass found in most bottles in Europe (a world leader in glass recycling).

Other glass producers are experimenting with “lightweighting,” making bottles lighter to reduce per-bottle energy use and emissions and lower transport weights. Earlier this year, Champagne Telmont began using bottles from glass manufacturer Verallia that, at roughly 4% lighter than the traditional style, are considered the lightest available bottles for sparkling wine. “Basically, less material is going to be more environmentally friendly,” says Katz. “As a consumer who’s environmentally minded, that’s a big turn-off to me if I pick up a bottle and it’s a very heavy, chunky bottle.”

Still, he says, “There’s a real resistance to changing packaging and even the weight of the packaging — and that’s an easy one.”

The big packaging picture

There are other packaging factors that play into the overall sustainability of a particular bottle of wine, including the stopper. Natural cork is biodegradable and can be commercially composted (or even recycled), while synthetic corks are destined to stick around in the landfill for a long time before they break down into microplastics. Cork oaks regenerate their outer bark and live for hundreds of years, meaning they can be harvested over and over again without having to be cut down — and contrary to a common misconception, are not currently endangered. (Sustainable forest management is an increasing priority, and research suggests that cork forests can actually sequester carbon.)

Aluminum screw caps are also preferable to synthetic corks because they can be recycled, as can the wire cages that come with sparkling wine. Wine capsules (the wrapping around the bottle neck) are sometimes recyclable, but mostly add more waste to the equation.

Although wine labels only account for around 1% of a wine’s carbon footprint, it’s likely that sustainability-minded wine producers will keep even this in mind. Paper labels are biodegradable; plastic labels not only create pollution before, during and after production, but they also adhere so well to the glass that it lowers the value of the bottle once it ends up at a recycling facility. Even paper labels, though, generally arrive on plastic liners (from which they are peeled off), but some are working on this, too: The packaging company Avery Dennison, for example, is making label liners partially from recycled plastic. Though it can be hard for consumers to see small changes like this — unless a winery clearly outlines its ongoing sustainability efforts — they can add up on the producer side.

So if you’re just dropping by the wine store for a simple bottle of red to put on the table Tuesday night, where should you start? In addition to understanding how the wine was produced — emissions aren’t everything, remember — opt for lighter bottles with biodegradable components. If you see a wine in less traditional but lower-impact packaging, give it a try.

Who knows? The next delicious glass of wine you drink may very well not come from glass at all.