Beer has its heart in glass

15 December 2020

Infinitely recyclable, essentially made from sand and heat, and well known to consumers as a form of packaging that can be easily disposed of, reused or refilled, glass is a material with many strengths. Though some have reservations about its fragility and its cost profile, for many premium products it is a material of choice. Greg Bentley of ABInbev and Mark Comline of Carlsberg discuss the benefits of glass packaging and why it is the preferred packaging material of beer.

The packaging industry is always on the lookout for cheaper, more flexible and more sustainable packaging materials. There is a need to combine innovative designs with barrier properties, cost with sustainability, and appearance with performance. Nevertheless, in the beer market, glass has maintained its position as the preferred material over many decades.

“I have been told by customers that the first chilled sip of beer, including the bottle feeling on the lips, can be the favourite part of a day,” says Mark Comline, Senior Global Procurement Director for Cans and Glass at Carlsberg.

“While glass has been around for a long time, the process of making glass has evolved to allow the large-scale production of unique shapes and optimised bottle designs,” he adds. “Ultimately, glass enables an overall drinking experience that is loved by many consumers.”

Among those who share a passion for glass bottles is Greg Bentley, Global Packaging Innovation Director at the world’s largest brewer Anheuser-Busch InBev (ABInBev). Bentley and his team focus on primary packaging at ABInBev’s Global Innovation and Technology Centre (GITeC) in Leuven, Belgium. Though not concerned with the design of individual brands, they focus on fundamental changes to primary packaging to ensure that it is lighter, cheaper and made more efficiently.

“Sustainability is also a key focus for us,” Bentley remarks. “In fact, it is something of an obsession for me. I tell my team that if they are not spending at least 50% of their time working on projects that are reducing the footprint of our packaging, then they are not doing the right things. Sustainability of our packaging is always a key consideration for any project.”

The company has set some ambitious 2025 sustainability goals, in which packaging is inevitably one of the main pillars. Glass plays an important role in that effort. Cullet – the broken or refuse glass that is crushed and ready to be remelted – is a key constituent in the manufacturing of beer bottles.

“Glass is 100% recyclable and customers know that,” he adds. “Glass goes back into glass. Glass bottles are made from glass bottles. Furthermore, you can break it and melt it using significantly less energy than it would take to make new glass from raw materials.”

Whatever its colour, glass is always green

In the early years of glass packaging, drinking beer and soda from returnable bottles was commonplace. The bottles could be refilled and reused many times, but the practice of returning bottles became less familiar with the introduction of steel and then, later, aluminium cans. Now, there is a steady resurgence in returnable bottles, at least in some markets.

Belgium is one of the European markets where the practice or returning bottles to be reused and refilled is on the rise. In the US, ‘bottle bills’ are being reintroduced in some aeras, mandating refundable deposits on beer and soft drink containers.

“Returnable glass bottles are designed slightly differently to be able to be used multiple times, in line with sustainable practices,” remarks Comline. “However, in countries such as Denmark, where deposit rates are above 90%, breweries, producers and importers choose themselves the type of bottles and cans to use for their brands but the law requires that a deposit be charged on all bottles and cans no matter the colour, shape or form.”

“In some markets, glass can be fully re-used and is returnable, or also has the ability to be recycled back into glass bottles,” he adds. “Where it is returnable, the sustainability aspect is critical to the entire product offering in a glass bottle.”

If not returned, glass bottles are relatively easy to recycle. As recycling becomes more commonplace around the world and more consumers take the time to recycle their packaging, both the cost profile and the sustainability credentials of glass continue to improve.

“In most markets, 40-60% of our bottles are made from recycled glass,” says Bentley. “It depends a lot on the market, as in some there are very low recycling rates, so the cullet is not as readily available. Globally, the average is 42.3% of our primary packaging made from recycled glass.”

“Sustainability has definitely been a key consideration of the glass industry with a lot of effort being placed on reducing the weight of bottles, reducing the energy to produce bottles and, where possible, re-using the heat from glass furnaces for other purposes,” says Comline. “Using more cullet has also been a focus area with some suppliers in some markets aiming to approach almost fully recycled content.”

Crucially, there is no reduction in quality if a glass bottle is made from recycled material or made new. There are benefits to the glassmaker if glass of the same colour is used throughout the cycle, but this is usually managed during the sorting process. While green and brown glass can be recycled together, it is important to keep clear glass separate.

A hard habit to break

Compared to other containers, notably aluminium cans, glass bottles have one weakness – their fragility. Cans dent, bottles break. Nevertheless, this has not been an impediment to the use of glass, even as newer and often cheaper alternatives have emerged.

“We are always investigating consumer pain points for glass,” says Bentley. “Refillable bottles are the most sustainable option, but they are heavier than one-way bottles or alternative materials. We want to make those bottles lighter and stronger, which is

theoretically possible. The technology exists to make unbreakable glass for cars that need bulletproof windows, but it is not affordable yet and we don’t need bulletproof beer bottles.”

“The process for making glass bottles is centuries old,” he adds. “It is a heavy industrial process and, let’s not forget, a very hot process. It has been around for a long time, but it is constantly being refined.”

Alternative packaging continues to hit the market, driven mainly by the sustainability agenda. Carlsberg, for instance, has been developing its Green Fibre Bottle, the world’s first ‘paper bottle’ for beer. In late 2019, it revealed two new research prototypes and announced that it is collaborating with other leading companies to develop paper bottle technology.

The prototypes are made from sustainably sourced wood fibres, are fully recyclable and have an inner barrier that allows them to hold beer. In one, the barrier is made from recycled PET polymer. In the other, there is a 100% bio-based PEF polymer film barrier, which is part of the company’s search for a fully bio-based bottle.

Would such a product spell the end for glass? Put simply, no. It would, however, provide another tool available in building a more sustainable future.

“We will always look for the best way to serve our consumers with the best quality beer,” says Comline. “Glass bottles definitely enable us to do this and will continue to be a part of our product offering in the future. What we have said is that we are on a journey to help consumers to live more sustainable lives by introducing a range of packaging innovations which will minimise the environmental impact of our beers.”

“I think a company like Carlsberg, with the industry’s most ambitious sustainability programme and a history of always improving the quality of the beer, should lead and work at offering a choice to consumers,” he adds. “If they want refillable glass bottles, they should be able to get it. If they want a bio-based and recyclable paper bottle, they should be able to get it.”

Glass persists as the material of choice in some settings, though it is not necessarily easy to make.

There are currently two main methods of making glass containers - the blow and blow method, which only suits narrow-neck containers, and the press and blow method that is used for jars and tapered narrow-neck containers.

In both, molten glass, heated to its plastic temperature of between 1,050°C and 1,200°C, is cut into a cylinder or gob, which is then guided into chutes and moulds. In the press and blow process, a metal plunger which presses the glass out to fill the moulds. The process is intricate and, as Bentley says, hot.

“Glass is not an easy material to manipulate, but the glassmaking process is hard to change,” he notes.

In terms of cost, the comparison with other materials varies. Refillable bottles are the most cost-effective option, as bottles are frequently used 40 or 50 times, with brewers able to pass on the cost saving to consumers. Using recycled glass also reduces the cost of raw materials, but even with new glass bottles, the cost of the material is not much more than the cost of aluminium to make cans.

Cost, it seems, is not the defining factor in choosing a packaging material for beer. The choice is determined more by the occasion at which beer is consumed.

“It is about having the right packaging for the right occasion,” says Bentley. “If you are at the beach, for example, or on-the-go then the right packaging might well be a can. In a bar or at home, then the glass bottle will deliver a better product due to the inert properties of glass, despite what experts in metals might say and despite the fact that PET gives you more flexibility in the production process.”

“Beer from a glass bottle is as close to perfection as you can get, and creating the right glass bottle is an art, as well as a science” he adds.

A badge of quality

Glass has kept its role in beer packaging throughout the years despite the many innovations in materials and packaging forms that have happened around it. This is only partly due to its sustainable credentials. Above all, it is a material that has strong associations in the minds of consumers.

“Glass brings a premium feel to packaging,” Bentley reminds us. “People don’t buy gin in plastic bottles. It also has an effect on product quality. With glass packaging, nothing gets into the drink and nothing gets out. With the amber colour added to the glass the beer is also protected from UV light, which can damage it.”

“Firstly, the glass bottle - like other packaging materials used - protects the beer quality and supports fresh the beer being delivered to the consumer,” concurs Comline. “Glass has excellent barrier properties to protect the beer from becoming oxidised. Within beer, the amber, green or blue colour of the glass, which is the case of 1664 Kronenbourg Blanc, protects the hops flavours in the beer from the sunlight.”

Drinking beer from a can is about the beer. Drinking beer from a glass bottle is about savouring the experience

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