The plastic or glass debate - what’s more sustainable?
Updated: May 19, 2021
Wine industry inspiration and sustainable event learnings.
Wine has been in glass bottles as long as I’ve been alive but only because I wasn’t born before the 18th century. Back then, wine was sold from the barrel and often stored in clay jars or leather satchels, known as wineskin. The move to glass helped to protect wine from oxygen and allowed for more controlled oxidation of wine through the cork which affects its flavour and quality (I’d recommend asking a sommelier for a more refined definition) as well as extending the shelf life of the product. Glass is also durable, can be used many times over and when recycled, keeps the material in use and out of landfill.
But is it the best solution?
On the face of it, the production process of glass has a lower environmental impact than that of plastic so naturally, this seems like the most sustainable solution. But when it comes to factoring in transport the difference in weight between glass and plastic means that 40% more energy is required to move the products from place to place without including the carbon output of the vehicles themselves. This is where the balance of impact changes and plastic is seemingly more sustainable.
However, the problem with plastic is the number of times it can be recycled, which varies depending on which report you read, but sits between 2-5 times. Whereas glass, in some cases, can be infinitely recycled. The materials are kept in use IF the bottles are sent for recycling. But even so, when all factors are included, not just the production process, the recyclable plastic bottles record a lower environmental impact simply because of the weight difference of glass.
“In many cases, plastics are actually better for the environment than alternatives”
Susan Selke, director of the school of packaging at
Michigan State University (qtd. in Gray, 2018)
In addition, plastic bottles are less likely to break which makes them safer and easier to transport. Less breakage also means less wasted energy to produce an item that ends up in landfill before it has even been used for the first time.
In an ideal situation, “we will drink wine poured from carbon nanotubes (rolled-up graphene)” (Jefford, 2018) but in a world where we are working our way through the environmentally friendly alternatives and bulk sale isn’t an option, we have to switch to the best solution we can. For wine manufacturers, recycled plastic is the better option. (sorry glass, you lost here)
The main problem for the wine industry will be tackling the perception of wine in a plastic bottle but that’s an argument for another essay.
If this whets your appetite, then pop to your Co-Op and look for:
Garçon Wines: 21st Century Eco Flat Wine Bottles created from pre-existing, recycled PET, not single-use plastic. Flat bottles also save space making transport more efficient too!
Event learnings and why materials matter
The Ellen MacArthur Foundation provides an extensive definition of the contributing factors to a Circular Economy namely by moving from the old model of Take-Make-Dispose to a circular model where products and materials are kept in use favouring “activities that preserve value in the form of energy, labour, and materials. “ This requires designers to consider durability, the reuse of products, how materials will be remanufactured and “recycling to keep products, components, and materials circulating in the economy” and out of landfill.
Therefore, if you’re aspiring for a circular and sustainable event - consider your materials carefully. The answer isn’t always obvious and in a climate where plastic is the enemy we should be careful not to dismiss it entirely because in some cases it may be a better option.
If we take the example of compostable cups, which have seen an upward trend at events as the plastic becomes criminalised, and we take a closer look, not all is as sustainable as it seems. On the surface, compostable sounds like a great alternative, the material breaks and filters into the earth feeding back into the environment in a harm free way, right? Wrong. Most compostable cups are actually only compostable industrially. Meaning for the cup to be composted, you need to return your cup to the retailer who should, although not always, send the item away to be commercially composted at a specialised facility. Industrial composting requires intense temperatures which cannot be replicated in a garden compost heap and most certainly not in landfill.
But what about putting them in the recycling bin? (I hear you ask)
Not an option either, the materials need to be separated and this operation is not available in public or in household recycling facilities. So that cup you consciously thought was doing good when you threw it in the recycling bin is probably going to landfill anyway and not breaking down there either.
Solution? Ask the right questions when choosing your materials!
For the cup example, ask your venue or caterer if the cups are commercially compostable and if they have a system in place to facilitate their transport to a composter. But apply the same lens to all of your sustainable material choices, make sure you understand the entire journey and don’t discount a product until you understand its whole lifecycle.
If you’re not sure about what questions to ask your suppliers, we’re working on some guides for you so keep your eyes peeled on our blog!