Everything You Need To Know About Zero-Emission Coffee Roasting

Janice Kanniah
April 15, 2021
zero emission roasting

Like most production processes, traditional coffee roasting produces a range of emissions and byproducts. Traditional gas-powered roasters use open flames, while ventilation systems are in constant use, all of which release carbon dioxide into the atmosphere.

Recent studies indicate that, on average, roasting contributes around 15% of the overall carbon footprint of coffee, equal to approximately 1.2 pounds in carbon emissions. These emissions have the potential to hamper the quality and volume of future specialty coffee harvests by affecting the environment.

As a result, a number of specialty roasters have started exploring ways of reducing the carbon emissions not only involved in roasting but at other stages of the supply chain too. Zero emission roasters, sustainable packaging, and offsetting initiatives have all been put forward as viable solutions.

To find out more about how to reduce carbon emissions, I spoke with Head Roaster at Belleville Brûlerie in Paris, Mihaela Iordache.

See also: Why Should Specialty Coffee Roasters Aim To Become Carbon Neutral?

zero emission coffee roasting

What Are The Potential Problems With Roasting?

The United Nations recently backed a study exploring which industries produce the most emissions. They discovered that over a third of emissions come from food production, processing, and packaging.

Coffee is no exception: the average flat white has a carbon footprint of 0.34kg based on all stages of its journey from seed to cup. And while farming overwhelmingly accounts for the most carbon emissions, the roasting stage also has an impact.

Mihaela Iordache is Head Roaster at Belleville Brûlerie, a roastery in Paris. She tells me that during roasting, a range of different gases and pollutants are released into the atmosphere.

“Cleaning, destoning, roasting, and cooling coffee all produce particulate matter,” she says. “But during roasting, a number of gaseous pollutants are produced, such as alcohols, aldehydes, organic acids, nitrogen, and sulfur compounds.”

Mihaela explains that natural gas-fired roasting machines produce high volumes of greenhouse gases like carbon monoxide and carbon dioxide (CO2) when combusting fuel to heat the machine. While these emissions (as well as smoke, odours, and other pollutants) are ducted to an external afterburner or filter system, this process also consumes a lot of fuel.

Greenhouse gases (GHG) are gases in the Earth’s atmosphere that trap heat, including CO2, methane, and water vapour. In the last century, human activities such as burning fossil fuels and deforestation have caused a jump in the concentration of GHG in the atmosphere. The result is higher global temperatures, or global warming, which can have a devastating impact on the long-term wellbeing of the planet. 

However, it’s not just the wellbeing of the planet that’s at risk. According to Mihaela, roasting can have an effect on the health and safety of those in proximity to the roaster.

“Carbon monoxide in particular is a potential respiratory hazard to workers in the coffee industry,” she says. “Therefore, reducing emissions is an urgent challenge, a matter of ‘must care’ rather than ‘should care’. The coffee industry must find carbon neutral and sustainable ways to move forward.”

zero emission coffee roasting

What Is “Zero-Emission” Roasting?

Although roasting contributes less than 4% of the total carbon emissions of a cup of coffee, it’s important for specialty roasters to do as much as they can to lower their carbon footprint.

Zero-emission roasting is a relatively new, yet highly effective way of reducing emissions in the coffee supply chain. Based on the development of new, energy-efficient roasters with single-burners, zero-emission roasting can reduce the carbon footprint of each roasting cycle by up to 90%.

Bellwether Coffee based in California is at the forefront of zero-emission roasting. Their sustainable roasters use electric heating elements that surround the roasting drums to achieve the same roast quality without using gas.

With no smoke, volatile organic compounds (VOCs), or particulate exhaust, it requires no additional ventilation or afterburner, thus considerably reducing the amount of energy required to power it. 

According to one study, investing in a Bellwether roaster saved more than 157 metric tons of GHG emissions based on the machine’s 10-year lifetime. This is the equivalent to having 389,578 light-duty vehicle miles removed from the road.

Similarly, the Loring Smart Roaster offers a cleaner, more energy-efficient way of roasting coffee thanks to its patented single-burner system. 

After realising that around 75% of the heat input involved in traditional roasting leaves via the chimney, the company’s founder, Mark Loring Ludwig, designed a roaster that eliminated the need for an afterburner, by recirculating the hot air. It’s estimated that the removal of the afterburner alone reduces fuel consumption by up to four times.

However, while zero-emission roasters are a positive step towards lowering the carbon footprint of roasters, they may not be feasible for all roasters. Mihaela believes that zero-emission roasteries will be more widespread in the future.

“A lot has already been achieved at an equipment level,” she says. “What we must remember however is that emissions must be monitored across all spaces — serving or manufacturing units, transport vessels, local, national, and international sales channels, and waste must also be recycled. There’s a long road ahead.”

sustainable packaging

Other Ways Of Reducing Emissions

Despite the obvious benefits of switching to a zero-emission roaster, there are other effective ways that specialty roasters can reduce emissions.

A paper published in the Resources, Conservation and Recycling Journal covered how improved management and product use in packaging can reduce carbon emissions. It found that switching to sustainable packaging materials could reduce emissions by 10%, while replacing single-use packaging for reusable packaging can reduce emissions by more than a third.

Mihaela agrees that sustainable packaging is one of the most effective ways of reducing carbon emissions. 

“Single-use plastics require significant amounts of energy to produce and have a short life cycle,” she says. “Replacing them with recyclable, biodegradable, or compostable materials (like kraft paper or polylactic acid) and using low VOC water-based inks will create a more eco-friendly product.”

Many roasters are aware that these materials exist, but are reluctant to adopt them as they believe they won’t be able to protect the coffee.

However, Mihaela says that customers on the fence should realise that environmental awareness is no longer a trend, it’s a requirement. She also believes that customers are likely to pay more for products with eco-friendly packaging.

“Extending the shelf life of roast coffee through degassing valves and resealable packaging is equally important. This helps preserve aroma and flavour, prevents oxidation, and keeps coffee fresher for longer.”

This can only take place if your emissions-reducing efforts are communicated to your customer base. This can be done by printing details of it (and how it should be disposed of) on your packaging, or sharing information on social media.

coffee roaster

Zero-emission roasting has become an increasingly important goal for many specialty coffee roasters. As concerns over the environmental impact of the coffee supply chain grow, lowering carbon emissions at each stage has become a priority for all those involved.

Although buying a whole new roaster may be out of reach for a lot of specialty roasters, there are lot of other ways of reducing carbon emissions. One of the most affordable yet effective is switching to sustainable packaging. At MTPak Coffee, we offer a range of recyclable, biodegradable, and compostable packaging options. Choose from a selection of customisable pouches, including stand-up, flat bottom, side gusset, and quad seal.

For more information on our sustainable packaging, contact our team here.

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