Rightweighting Glass Wine Bottles
Suppose that we had the technology to create a “wonder material” to package wine? It would need some essential properties. For example, it would come from abundant natural materials. And be completely inert, not affect the taste and have the ability to preserve the wine for decades. It would come in a range of shapes and sizes yet withstand handling and pressure. And even be quickly and infinitely recyclable. Wouldn’t that be amazing? Well, we have it; it’s called the glass bottle. And though there are alternatives, this has been our principal wine container for centuries. But they are often heavy and bulky because any weak spots risk breakage. However, reducing bottle weight without increasing breakage has essential environmental benefits. Hence this article is about this process, called rightweighting.
Sustainability is a journey.
Wine takes a long journey from the grapevine to our wineglass. Fully addressing wine sustainability means more than winegrowing. After winemaking, an intricate distribution chain supplies the wine to us. It involves making business choices about packaging, transportation and waste disposal. These have a significant role in increasing sustainability by reducing raw materials, carbon footprints and greenhouse gasses.
Some propose replacing glass bottles with alternatives that offer less weight and more space efficiency because of weight and bulk. That isn’t without merit in some instances, but their materials may cause other undesirable outcomes. As usual, there is no simple magic bullet. Glass offers a longer shelf life and doesn’t allow oxygen and CO2 to migrate through the packaging into the wine. And because glass doesn’t react with the wine, it never impacts taste and quality.
As well as the material advantages of glass, the glass industry has huge-scale manufacturing and disposal infrastructure. Glass bottles are also well-liked by consumers. We see them as safe, healthy and environmentally friendly. Hence a mix of initiatives can improve their sustainable credentials markedly. That’s preferable to throwing out the baby with the bathwater.
Sustainability requires a mix of initiatives.
This mix of initiatives is all about doing more and better with less. Briefly, some of these include:
- Glass manufacture. Giant high-temperature furnaces need to operate 24/7 for efficiency and enormous production. Unfortunately, they currently burn natural gas, a fossil fuel. The glass industry has taken huge strides to reduce energy usage, and furnace energy efficiency has improved by over 50% over the past 40 years. As part of the intention to achieve net-zero carbon, there is a proposal to build the first commercial glass furnace using renewable electricity. Meanwhile, in 2021, there will be a trial substituting biofuels for natural gas*.
- Glass recycling is essential and something we can all do. Thankfully, glass recycling rates are high, though they can still improve. The UK is at 68%**, Europe at 76%. A plan for 90% glass recovery for recycling by 2030 is achievable. The recycled glass needs 25% less energy and has 30% less CO2 than making new glass from virgin materials, so the glass industry can’t get enough of it. Indeed, every tonne of recycled glass saves the energy equivalent of 74,000 smart-phone recharges! A new green wine bottle can be up to 95% recycled glass. Clear (flint) glass has a lower recycled content because less clear glass is currently available but can still reach 40%.
- While most of our wine imports are already in glass bottles, there has been a doubling in bulk container shipments over the last ten years. Now 37% of wine imports are locally bottled in the UK.
- Rightweighting’s significant role is explained below.
Reducing weight – Rightweighting
Reducing the weight of glass bottles in the supply chain brings proven benefits in reducing raw materials, greenhouse gas emissions and carbon footprint. It can apply to all types of wine. In the case of many sparkling wines, there is no substitute for a glass bottle. It’s because much sparkling wine production uses the traditional “classic” method bequeathed by Champagne, where a glass bottle is an essential part of the process. No other way can make sparkling wine of such quality. Of necessity, such bottles must withstand this process and endure up to six atmospheres of gas pressure. That’s three times the pressure in an average car tyre, equivalent to over 5 kg of weight on every square centimetre of glass. And it must be able to do this for many years. No wonder that traditionally these are amongst the heaviest bottles.
Reducing weight is sometimes called lightweighting. However, with wine bottles, rightweighting is a more accurate description. The goal is to optimise the weight and resolve any conflicting stakeholder needs in the supply chain, namely wine producers, bottle manufacturers, brand owners, bottling lines, transporters, wholesalers, retailers, consumers and the environment. Achieving rightweighting is a win-win situation for all because, as well as environmental benefits, there are substantial business gains, for example, in logistics cost savings.
How low can you go?
Surprisingly, the demand for much lighter bottles has only been over the past 15-20 years. In the glass bottle making process, molten glass blows into a mould. It’s then only as strong as its weakest spot. Hence the more complex the shape, the more potential for weak spots. Compensation for weak spots was by having thicker glass walls, which adds weight.
However, the glass industry developed “narrow neck press and blow” or NPBB. The video link shows how. Suffice to say that this enables a far more consistent thickness of glass in bottle manufacture, eliminating weak spots and allowing thinner glass, so saving significant weight. Thanks also to computer-aided design (CAD), these bottles are often stronger than their heavyweight counterparts! Hence while an average 750 ml still wine bottle was around 500 g in weight, such rightweighting means a standard Burgundy-style bottle is typically 395 g while a standard Bordeaux-style is 345 g. These are available from stock, while bespoke designs can go down to 300 g.
Significant weight savings
Those weight savings doesn’t sound much until you pick the bottle up and discover a 20-30% reduction in weight. Now, the UK is the second-largest importer of wine in the world. In 2019, the UK imported over 1.4 billion litres of wine. Hence, the rightweighting potential becomes enormous, further magnified by distance and transportation method.
Meanwhile, there is little or no correlation between the weight of a glass wine bottle and wine quality. Those wine brands still insistent on intricately designed bottles or prestigious decoration only succeed in making overweight bottles. Instead, enlightened brands are rightweighting and redesigning the labels to be more attractive, recognisable and memorable. Below are just a few examples.
Champagne was the first wine region to calculate its carbon footprint back in 2003. At this time, they were surprised that packaging accounted for 33% of their emissions, a figure now found to be commonplace! Since then, their region-wide voluntary sustainability plan includes a rightweighting initiative. That has reduced weight without affecting performance, safety, or prestige. In short, they reduced the standard Champagne bottle weight from 900 g to 835 g, a reduction of 7%. By 2018, this had reduced the region’s carbon footprint by 20%, with some 8,000 tonnes of CO2 saved per annum. As the worlds foremost premium wine brand, Champagne shows that rightweighting works. If Moët & Chandon can do it, so can everybody else!
The UK’s Waste and Resources and Action Programme (WRAP) and the UK glass industry developed a 300 g bottle during their GlassRite project. WRAP calculated that if adopted for all still wine sold in the UK, it would save 153,000 tonnes of glass and cut emissions by 119,000 tonnes of CO2 – every year.
Distributors, Global Brands and Supermarkets
Distributors, global brands and supermarkets are all rightweighting, sometimes in partnerships. In 2019, Accolade Wines, the fifth largest wine company globally, introduced a 330 g standard bottle. Meanwhile, Kingsland Drinks worked with Tesco to introduce lighter bottles and, with the Co-op, reduced a 650 g bottle to 484 g and a 460 g bottle to 400 g.
Viña Santa Rita Estates, Chile
Viña Santa Rita Estates has five wineries in Chile and another in Argentina and are one of the world’s most respected wine brands. They are leaders in wine quality, exports, business ethics and sustainability. They found that 43% of their emissions were packaging related, with a further 46% related to transportation. In consequence, their glass bottles are now 24% lighter.
As with all human activities, Wine has a carbon footprint and emits greenhouse gasses throughout its journey from grape to glass. In particular, packaging and transportation are areas where significant reductions are possible. Rather than face elimination, glass bottles have a vital role to play. A mix of initiatives, including rightweighting, offer proven environmental improvements. So far, this has been an evolutionary process with a long way to go, but enlightened wine producers, brands and even entire wine regions are making considerable progress. Rightweighting is a practical solution using existing technologies and infrastructure. It’s socially equitable, economically viable and environmentally friendly. Less really is more.
In short, there is rightly a place for glass wine bottles; we only need to use them more wisely. Hence as wine drinkers, we can help play a part too – let’s get our glass recycling to 90%!
*Update, February 2021. British glass bottle manufacturer Encirc has now reported the successful trial of biofuel-powered furnaces making glass wine bottle from 100% recycled glass. This cuts down manufacture emissions by 90%
**Official DEFRA UK glass recycling figure, published in March 2020.
Like to know more about sustainability and glass wine bottles? Here’s an article about the new Sustainable Wine Great Britain (SWGB) initiative. And now a third piece covers the UK Bulk Wine market here.