21/02/2025

When we talk about the wine industry, the spotlight is often on the producers—their dedication, craftsmanship, and sustainability efforts in creating premium wines. Winemaking has long been the focal point of industry discussions, but behind every great bottle is a network of essential contributors who ensure that wine reaches consumers in its best form. From packaging to preservation, these often-overlooked players are just as vital to the process.

To highlight one such unsung hero, we spoke with Kevin André, Head of Sales, North America at Diam Bouchage. As the world’s second-largest cork manufacturer and buyer, Diam Bouchage has built a reputation for pioneering technological advancements that cater to both the wine industry and consumer demands. In this conversation, we delve into their research and development process, upcoming projects, and the innovations that have cemented their position as a global leader in cork manufacturing for over two decades.

Edited excerpts from the interview.

Diam has been at the forefront of closure innovation for 20 years. What do you see as the biggest breakthroughs in your technology, and how have they transformed wine aging?

When we started 20 years ago, the cork industry was struggling with a major issue—TCA, commonly known as cork taint. No one had found a reliable solution, so our first priority was to eliminate that problem. That breakthrough is what put Diam on the map. We didn’t invent the process, but we adapted an existing technology—one originally used by Maxwell, the coffee makers, since the 1950s. This process uses CO₂ in its supercritical form at differentiated pressures to extract TCA, along with 150 other unwanted molecules from cork, which is why it’s still a unique process on the market!

Beyond addressing cork taint, another key challenge was cork’s natural inconsistency—some pieces were good, others weren’t. To solve this, we took a different approach by granulating the cork, which allowed us to recompose it in a way that ensures consistency. Our process guarantees uniformity while maintaining the natural elasticity of cork over time. Of course, elasticity does gradually decrease, but with our technology, we can predict and guarantee its performance. That’s where our different Diam corks come in—Diam2, Diam3, Diam5, Diam10, and Diam30. Each number indicates the number of years the cork’s elasticity is guaranteed as long as it is stored at 68°F. And when the bottle is stored at 58°F or cellar temperature, the elasticity doubles. This was a major breakthrough because, before Diam, there was no way to guarantee how long a cork would last. Now, winemakers can choose closures with precise aging potential, something that was previously impossible.

Oxygen transfer is actually Diam’s third major breakthrough. By making our corks consistent, we’ve been able to accurately measure how much oxygen enters the wine over time—something previously only possible with screw caps, which have a predictable and uniform oxygen exchange. Traditionally, corks allow more oxygen transfer than screw caps, but with our technology, we can precisely measure and tailor that transfer. This means winemakers can now choose different corks based on the type of wine, how long they intend to age it, and the level of oxygen exposure they prefer.

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Sustainability is a growing priority in the wine industry. How does Diam integrate environmentally responsible practices into its cork production and materials sourcing?

We've been tracking our carbon footprint since 2007 and have been at the forefront of sustainability efforts. For Scope 1 and 2 emissions—those directly related to our operations—our goal is the reduction by 15% of our Carbon Footprint in 2025 on the 3 scopes altogether, which entails a 55% reduction on scope 1 & 2. Scope 3, which includes our suppliers and external partners, is a work in progress, but we're actively addressing it.

We take several approaches to sustainability. Firstly, cork forests are carbon sinks, and sourcing from those is the most sustainable solution, though it can be challenging to verify every aspect of the supply chain. Our production facilities are strategically located in France, Portugal, and Spain—near the cork forests—to minimize transportation impact. In Europe, we follow a "Freight 21" policy to reduce truck trips between companies, cutting down unnecessary transport emissions.

On the energy front, we prioritize renewable sources. We are building a 40 acre solar farm next to our largest plant in Spain, which will allow us to be completely energy-independent during the day. Additionally, we are developing systems to recover heat from our machinery and burn production waste at night to generate power, further reducing reliance on external energy sources. Another important initiative is forest restoration. In France, the cork industry was largely abandoned in the 1950s, leaving many forests unmanaged. We are actively working to clean and redevelop some forests, while also enforcing a sustainability project where we plant trees with an irrigation system for a more efficient sourcing (which would mean speedy growth and shorter time-spans between each harvest). 

Origine Closures by Diam Bouchage

You emphasize winemakers’ ability to choose the right Diam closure to match their wine’s evolution. How do you help producers determine the ideal closure for their specific cuvées?

It all comes down to relationships and trials. While we specialize in closures, we’re not winemakers ourselves. Even though our company includes enologists and winemakers, we don’t have the same intimate knowledge of a producer’s specific wines, their clientele, or their market. That’s why communication is key. We take the time to understand how a winemaker crafts their wine, when they plan to release it, and how consumers will be drinking it. This helps us recommend closures with the right elasticity over time and the appropriate level of oxygen transfer. It’s about aligning with their vision—how they want the wine to taste in two, five, or even 30 years. Trialing is essential. Wine is a natural product, and even from the same vineyard, last year’s vintage won’t be identical to this year’s. 

Over the past 20 years, we’ve built strong expertise, and most winemakers already have a clear idea of what they want. When working with new clients, we draw insights from existing collaborations and conduct extensive global research. For instance, we currently partner with universities worldwide to conduct ongoing studies into different varietals—Malbec in Argentina, Shiraz in Australia, Pinot and Chardonnay in Burgundy —analyzing how they evolve over time with varying levels of oxygen transfer. We then provide these insights as a resource for winemakers. Our role is to support, not advise—helping them make informed choices based on their needs.

Many brands seek closures that reflect their identity. What customization options does Diam offer, and how can closures enhance a wine’s branding?

Since we recompose corks rather than using traditional punched corks, they naturally have a different appearance. Some brands appreciate this modern look, while others prefer something closer to the classic aesthetic. To accommodate different preferences, we’ve developed customization options that mimic the look of traditional corks. For example, we introduced fine lines on the sides of our corks to replicate the natural striations seen in punched corks. This helps create the visual impression of a traditional closure while maintaining the benefits of our technology. We also offer different washes to adjust the cork’s color. Naturally, cork has a slightly darker hue, but some brands prefer a lighter tone or even a bright white finish, and we can customize accordingly. Beyond aesthetics, branding plays a big role. We provide full printing capabilities, allowing winemakers to print almost any design on the side of the cork, offering a unique branding opportunity.

We have three major research branches: Naturity (bio-based solutions), Oxygen Transfer (performance and permeability), and Aesthetics. The Aesthetics division has led to innovations like the striated lines, and this year, we successfully developed a cork—the DIAM Collection—that looks almost identical to a traditional punched cork, delivering both visual authenticity and technical reliability.

For brands with a strong focus on tradition—whether in marketing or customer experience—we now have a solution that blends classic aesthetics with DIAM performance. Essentially, we can customize our closures to match nearly any brand identity.

Diam Bouchage unveils Collection by Diam Closures at Vinitech Trade Show and will be on market by the end of 2025 (Image Copyright attributed to JC Milhet)

With evolving winemaking techniques and consumer preferences, what are the biggest trends you see shaping the future of wine closures?

The biggest trend shaping the future of wine closures is Oxygen Transfer. Consumer preferences vary widely across the world, and winemakers need precise control over how their wines evolve in the bottle. Mastering and controlling Oxygen Transfer is essential. Right now, Diam is the only company that has truly focused on this aspect. The cork industry has traditionally been resistant to change, with a narrow, conventional mindset. But 20 years ago, we took a different approach—one rooted in technology and science. No one else looked at the importance of Oxygen Transfer as much as we did, and deepening our knowledge in this area allowed us to make significant advancements. Our goal is to offer a range of Oxygen Transfer options tailored to each winemaker’s needs, helping them achieve the perfect closure for their wines.

Another challenge we’re working on is closures for the no- and low-alcohol (NoLo) category. While this segment is still emerging, it's growing steadily. The challenge with NoLo wines is microbial stability—without alcohol to act as a natural preservative, these wines are more vulnerable to spoilage. That means closures must be designed to maintain a microbiologically clean environment. Unlike traditional wines and spirits, where alcohol helps prevent contamination, NoLo products require extra attention to ensure longevity and freshness.

These are the key areas where we see the future of wine closures heading—more precise Oxygen Transfer control—and solutions tailored for the growing NoLo market.

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Looking ahead, what challenges and opportunities do you foresee in closure technology, and how is Diam positioning itself to stay ahead of the curve?

In terms of technology, we’re already ahead—but staying there requires continuous research and innovation. When we first introduced our technology, many in the cork industry dismissed and criticized us. Now, those same competitors are scrambling to catch up, often claiming they offer the same quality at a lower price. But it's not that simple. We know that maintaining our leadership means we can’t afford to be complacent. That’s why we’re constantly searching, creating, and inventing. This year, we’re rolling out new innovations, with even more in development for the future. Our focus remains on anticipating what customers need—both winemakers and their consumers—and finding breakthrough solutions, just as we did with our Diamant® cork purification process and Oxygen Transfer technology. Listening to our clients and staying ahead of industry demands will keep us at the forefront.

One of the biggest challenges ahead is climate change. The Mediterranean basin, where most cork is harvested, is becoming hotter, which directly impacts cork production. Poor harvests lead to price increases, and if conditions worsen, supply could become a serious issue. That’s why one of our key priorities is investing in the preservation and sustainable management of cork forests. 

Another challenge is declining wine consumption. While the market seems to be approaching stabilization, shifting consumer habits mean we must adapt. At Diam, our strategy is to focus on the high-end segment. We’ve always positioned ourselves in the premium market, but now we’re expanding into the ultra-premium category, which has traditionally relied on natural punch corks. This segment is where we’re seeing significant growth, capturing market share from competitors. Meanwhile, mass-market closures are either disappearing or trending toward low-cost alternatives—neither of which align with our expertise or business model. Instead, we’re reinforcing our leadership in the premium sector and making inroads into the highest tiers of the market.

Of course, competition is another challenge, but that’s the nature of being a leader. Others will always try to catch up, but our goal is to stay ahead by pushing the boundaries of technology, sustainability, and innovation.

Header image sourced from Kevin André.

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