Aluminium is one of the world’s most widely used metals. It’s three times lighter than iron, almost as durable as steel, flexible, easy to process, and corrosion resistant.
As it binds easily with other materials, it’s used to manufacture everything from frying pans to smartphones. And, because it’s both abundant and infinitely recyclable, there is little danger of it running out anytime soon.
These qualities — in addition to its high barrier properties – have long made aluminium a popular choice for multilayer coffee packaging. For decades, roasters have used aluminium-lined coffee bags to protect their roasted coffee from heat, moisture, light, and oxygen.
However, when welded to another material, aluminium becomes notoriously difficult to recycle, often requiring specialist facilities to separate them. As such, roasters are increasingly turning away from aluminium-lined coffee bags in favour of more sustainable alternatives.
Among the most popular of these alternatives is PLA (polylactic acid), a bioplastic made from cornstarch that is not only renewable, but will completely break down within 90 days when placed in a commercial composting facility.
Why have roasters historically used aluminium to line their coffee packaging?
Coffee packaging has been used for centuries. In the 1700s, sellers used greased leather or beeswax-treated paper as packaging materials, and tin foil pound paper and paper bags began to emerge in the 1800s.
In the late 1800s, the foil-lined paper bag was patented in the USA and roasters started shipping tin cans of coffee to customers across the country. Both tin cans and foil lined bags were used for several decades afterwards. While tin cans eventually fell out of favour due to their weight, rigidity and cost, metallic lined bags have remained popular ever since.
There are many reasons as to why this metal is favoured for lining coffee bags over others. For starters, it’s non-toxic and food safe. It can also be rolled eight times thinner than a banknote, which means it won’t significantly add to a packaged product’s weight.
Furthermore, it won’t melt, change shape, or develop an odour at high temperatures. It’s impervious to moisture and oils and won’t rust when exposed to them. It also blocks out light, oxygen, microorganisms, and bacteria.
Although it can be costly to extract and refine aluminium, it makes up for this by being one of the most recycled materials on the market. Recycling aluminium saves over 90% of the energy required to produce it, greatly lowering its cost.
Is aluminium coffee packaging environmentally friendly?
While aluminium is recyclable, its coffee packaging applications can prevent this from happening entirely. Most roasters use multilayer packaging, which involves placing an aluminium layer on the inside and an easily printable material like kraft paper on the outside.
Aluminium is bonded to the top material using coextrusion or lamination. Coextrusion melts aluminium into granules or pellets before extruding and cooling it, while lamination directly bonds it to another material. Unopened, this aluminium layer can protect coffee for up to 12 months before it begins to lose significant aroma and flavour.
The problem arises when it’s time to dispose of and recycle this packaging. These layers can be challenging to separate, and not all recycling facilities have the equipment and facilities to do so.
Sadly this means that these types of coffee packaging often end up in a landfill, where it can spend years decomposing. Alternatively, it can be incinerated, but this contributes to air pollution.
Thankfully, alternative lining materials now exist. These materials perform as well as aluminium does and are affordable. More importantly, they can easily be separated from their top materials so that they can be properly recycled.
Using PLA to line your coffee packaging
If you’re looking for an alternative to aluminium that’s affordable, easy to access, and recyclable, polylactic acid (PLA) is the solution.
PLA is a non-toxic bioplastic created by fermenting renewable plant starches like rice or sugarcane. The fermentation process produces filaments similar to that of traditional plastics, which can be moulded, shaped, and coloured to the manufacturer’s exact specifications.
More importantly, PLA takes just 90 days to decompose. While its shorter lifespan makes it best suited to packaging coffee that will be consumed within six months, this is no problem for roasters who offer subscription services and smaller coffee volumes.
Research shows that customer experience will likely be unaffected should you make the switch. A comparative study of coffee barrier materials shows that consumers want coffee to smell and taste good for as long as possible.
While customers understand that packaging can help preserve these traits, research suggests that there is no particular barrier material preference. Rather, they are happy to accept any material that does the job.
It’s important to understand that PLA requires specific conditions for decomposition. However, as it can easily be separated from other materials, it won’t hold up or halt the recycling process entirely, unlike aluminium.
If you’re considering integrating PLA into your packaging, there are a few things worth keeping in mind. For instance, are your local recycling facilities equipped to handle PLA or other bioplastics?
You’ll also need to clearly communicate to customers that if they keep their packaged coffee for longer than recommended, it could seriously degrade in quality.
Take advantage of the space provided by your coffee’s outer packaging to communicate this to customers, and clearly specify which aspects of your packaging are recyclable and compostable. For example, customers might need to remove degassing valves or zip seals from the packaging before placing it in a recycling bin.
You can also use this space to outline your commitment to using sustainable packaging that’s good for the planet.
Understanding that not all aspects of your coffee packaging can be recycled may encourage you to reevaluate your packaging choices.
Ideally, your packaging provider should provide you with a full range of recyclable or compostable packaging elements, ranging from your packaging lining, to your choice of ink, and even the type of degassing valves used.
MTPak Coffee can assist you with all this and more, while giving you total creative control of the design process.