The move towards zero-emission coffee roasting

Antony Papandreou
November 10, 2022
The move towards zero-emission coffee roasting

Generational movements, such as Gen Z’s intense focus on sustainability, can have a lasting effect on how businesses operate. 

Notably, a 2017 study showed 87% of consumers have a more positive image of a company that supports social or environmental issues. Therefore, it is only natural for businesses to respond to this consumer behaviour. 

In recent years, leaders within the coffee industry have shown their support for the shift toward sustainability. As a result, more attention is being given to each segment of the value chain, from farming to disposing of used coffee grinds. 

Regardless of its overall impact on the environment, each segment is being held accountable by consumers. 

Notably, there are blind spots in the reporting, but coffee’s impact on the environment can be broken down. Around 68% of emissions come from coffee farming and processing, 11% from brewing or serving, and between 4% to 15% from transportation, roasting, and packaging combined. 

Consequently, more roasters are reducing their carbon footprint by investing in sustainable coffee packaging and making a move towards zero-emission coffee roasting.

Read on to discover the positive impact zero-emission roasting can have on the environment and the operators. 

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An image of a coffee roaster dialling a roast profile on a coffee roasters in an article on zero-emission coffee roasting

Coffee roasting and carbon dioxide emissions

Many consumers tend to romanticise the smell of roast coffee. 

In reality, roasting coffee can be a dusty affair. While the aroma is indisputably delectable, the fumes released during the roast process are often less than desirable.

Diacetyl occurs naturally in unflavoured coffee as a byproduct of roasting coffee beans. These and other volatile compounds are released into the air while roasting and grinding coffee. 

Notably, diacetyl is known to cause a lung disease known as “popcorn lung”. However, the concentrations in commercial roasting facilities are far below those expected to cause even minimal responses in the human respiratory tract.

However, it is still important to follow safety protocols. It is important to note that these studies were carried out using non-flavoured coffee. 

Other than the volatiles created during the roast, other emissions happen as a byproduct of the process. For instance, traditional drum roasters pull fresh air from the surrounding environment. This air goes through the burners, through the drum and out the exhaust. 

Heat transfers to the beans through convection, but a significant amount is lost through the exhaust. As roasting requires a stable high temperature, a considerable amount of energy is committed to the burners to compensate for the loss. 

To give some context, the energy required to maintain temperature is similar to running a family-size car. 

Another consideration is the carbon dioxide (CO2) produced during the roast on account of the partial combustion of the beans. 

Trapped in the porous cell structure of the beans, CO2 is released over time, but most of the degassing takes place within the first 72 hours

If roasting facilities lack proper ventilation, this may lead to a poor working environment with bad air quality, resulting in headaches, nausea, weakness, dizziness, and confusion. 

The dust from green coffee can also make the work environment unpleasant for staff if the ventilation is inadequate. 

As well as the volatile compounds mentioned, coffee roasting also emits carbon monoxide (Co),  carbon dioxide (CO2), and methane (CH4), which are all harmful greenhouse gases that trap heat in the atmosphere. 

Buying an afterburner can minimise this problem and reduce emissions, however, the energy cost can be high. 

An image of light roasted specialty coffee beans in a metal scoop being held by a coffee roaster in an article on zero-emission coffee roasting

What is zero-emission coffee roasting?

As the issues surrounding the energy inefficiency of traditional coffee roasters become more defined, so do the solutions. 

Well-known brands such as Loring can boast that it is 80% more fuel efficient than a traditional roaster and smokeless without needing an afterburner. 

And Loring is by no means alone when it comes to energy-efficient roasting – Bellwether Coffee, Roastair, and Typhoon are also leading brands in the sector. 

Energy-efficient machines could help not only reduce emissions, smoke, and other air contaminants but also save the business money. 

Businesses can reduce their liability in the event of price hikes by reducing dependency on fossil fuels.

While each energy-efficient roaster has its unique design and technology, they share a common thread. The energy that flows straight out of the exhaust is up to 80% of the input heat. 

By focusing on the exhaust, manufacturers can increase efficiency while simultaneously addressing the issue of air pollutants. 

Furthermore, circulating the hot air through the closed system cleans it without negatively affecting the taste of the coffee. This negates the need for an afterburner, which is also highly energy inefficient and expensive. 

However, to achieve zero emissions, roasters will have to look further than their equipment and consider the entire operation. 

One such roastery that is taking significant steps to reduce carbon emissions and become carbon neutral is Glen Lyon Coffee Roasters.

The roastery is owned by Jamie Grant and his wife Fiona. The website states the roastery works to reduce its electricity usage by bulk roasting on a more efficient 25kg roaster.

In 2021, the company invested in an initial bank of 16 solar panels fitted on the roastery roof. Additionally, the team uses propane to power the roosters. Propane produces as much as 38% fewer greenhouse gas emissions than other fuels. 

Jamie calculated their total carbon emissions for 2021 to be 17,080kg. 

An image of a barista cleaning an espresso machine by running water through it in an article on zero-emission coffee roasting and reducing water use

How else can roasters reduce their carbon emissions? 

The first step in offsetting carbon emissions is to implement efficient strategies to reduce them. 

For roasters, an effective first step would be to consider the flow of operations to see if there are ways to reduce energy consumption and water use

Additionally, roasters can choose to source low-carbon coffee varieties. Compared to standard varieties, these coffee varieties supposedly deliver up to 50% more yields per tree.

Furthermore, they use the same amount of land, fertiliser, and energy, which results in up to a 30% reduction in the CO2e footprint of the beans.

An image of coffee roasters packaging roast coffee in sustainable coffee packaging made from multilayer LDPE coffee bags in an article on zero-emission coffee roasting

One of the fastest, most effective ways roasters can reduce their carbon emissions is to work with reputable packaging manufacturers who use sustainable materials. 

Additionally, roasters can use their coffee bags to help educate customers about the impact of climate change at origin. This way, customers will understand the importance of supporting ethical and conscientious roasters.

MTPak Coffee offers a range of sustainable coffee packaging made from eco-friendly materials, such as kraft or rice paper with a LDPE or PLA lining.

Our team is happy to work alongside roasters to design and custom-print coffee bags with our digital printing technology to highlight their low carbon coffee offerings or sustainability efforts. 

We have a quick, 40-hour turnaround time and a fast 24-hour shipping time, allowing us to offer low minimum order quantities (MOQs) of packaging, no matter what size or material.

For more information on sustainable, custom-printed coffee packaging, contact our team

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