In Ethiopia, also known as the birthplace of coffee, it is common to find locals roasting the fruits of their labour in a large pan over an open fire.
That said, coffee roasters are essential tools that help transform green coffee into deliciously fragranced, roast beans that fuel an entire industry.
Notably, the market for coffee roasters was valued at $337.82 million in 2021 and is expected to reach $521.5 million by 2028.
As with any industry, coffee roasters have developed over time. For instance, the traditional wood-burning methods used in Ethiopia inspired the drum roasters that tend to dominate the modern industry.
While drum roasting is the older and more traditional method, air-roasting or fluid-bed coffee roasters were introduced during the 1970s.
Although air-roasting has been around for 50 years, it is still classified as new, and many roasters are only now experimenting with the method.
Read on to learn more about air-roasting coffee and whether it is the best method for your business.
What is air-roast coffee?
A chemical engineer by trade, Mike Sivets is credited with developing the concept of air-roasting coffee over 50 years ago.
While he began his career in the industry working in the instant coffee division of General Foods, Mike only invented the fluid bed roaster after leaving the coffee sector.
It is reported his interest in coffee roasters began when he was tasked with designing instant coffee plants.
At the time, coffee was only roasted in drum roasters, and through his research, Mike discovered multiple flaws in the design that were severely impeding the capacity of output.
In time, Mike moved on to work manufacturing plants for polyememes for polyurethane, and this is where he designed a fluid bed system to remove water molecules from magnesium pellets.
His work garnered the attention of German engineers, and soon, there were discussions about applying the same technology to coffee roasting.
This reinvigorated Mike’s interest in coffee and he invested his time and effort into designing a fluid-bed coffee roaster – the first machine to use air-roasting.
While it took Mike many years to build a functioning model that could scale production, his patented design was the first major innovation in coffee roasting in almost a century.
Fluid bed roasters, or air-roasting, work by circulating a channel of hot air through the coffee beans. The beans are lifted by this “bed” of air, coining the term “fluid bed roasting”.
A typical air roaster contains multiple sensors that help you measure and control the real-time temperature of the beans. Additionally, air roasters allow for the manipulation of variables such as temperature and airflow to achieve your desired roast.
How does air-roasting compare to drum roasting?
The fundamental difference between air and drum roasting is the method used to heat the beans.
In the more popular drum roaster, heat is applied to a rotating drum and the green coffee is dropped into the drum. The drum spins consistently to ensure the roast is even.
In a drum roaster, heat is transferred into the beans through a mix of around 25% conduction and 75% convection.
Alternatively, air-roasting relies solely on convection to roast the beans. The column or “bed” of air keeps the beans elevated and ensures the heat is evenly distributed.
In essence, the beans are wrapped in a cushion of hot air that can be carefully controlled.
One of the reasons air roasters are gaining momentum in the specialty coffee industry may be due to the difference in taste.
It is important to note that taste will heavily depend on who is roasting the coffee.
However, air-roasting is unlikely to produce a smokey taste, as the machine removes the chaff throughout the roasting process, reducing the risk of it burning.
Additionally, air-roast coffee also tends to be on the acidic side of the taste spectrum compared to drum roasters.
Air roasters often produce a consistent roast that tends to give a uniform flavour profile compared to drum roasters.
The benefits of air-roasting coffee
The differences between conventional drum roasters and air roasters go beyond taste and flavour profiles.
There are also significant operational differences that can impact your business to a great extent.
One, for instance, is roast time. A fluid bed roaster can roast coffee in almost half the time of a traditional drum roaster.
A shorter roast is less likely to produce unwanted compounds that often bring undesirable notes to the coffee, especially for specialty coffee roasters.
For roasters seeking to reveal a purer representation of the bean characteristics, a fluid-bed roaster can be your best option.
Second, is chaff: an inevitable by-product of roasting that can present a few hazards to your business.
First, it is highly combustible and if not disposed of carefully, it may catch fire and stop your complete operation. Another consideration of the speed at which chaff burns is the smoke it creates.
Fluid bed roasters consistently remove the chaff and eliminate the chance of producing a smokey-tasting coffee due to chaff combustion.
Third, air roasters give an accurate measurement of the bean temperature using a thermocouple.
This gives you transparent and accurate information about the bean, which can help you replicate that same roast profile with precision.
As a business, the consistency of your product is what will keep customers coming back for more.
While drum roasters can do the same thing, it often requires more experience and skill from the roaster to do so.
When it comes to maintenance and infrastructure, air roasters are unlikely to require massive changes to your current facility compared to traditional drum roasters.
And while both types of roasting devices require cleaning and maintenance, air roasters are often quicker to clean than drum roasters.
Air-roasting uses a recirculation system that intelligently reuses the heat created by roasting to pre-heat the coffee beans, making it one of the more sustainable roasting methods.
The ability to conserve and recycle energy by cutting down the process of reheating the drum in between batches can reduce carbon dioxide emissions by an average of 25%.
This can help you save energy, as an air roaster will not require an afterburner like traditional drum roasters.
Another way to boost sustainability credentials in your roasting business is by investing in biodegradable, compostable, or recyclable coffee packaging and takeaway cups.
At MTPak Coffee, we offer a range of 100% recyclable coffee packaging options made from renewable materials such as kraft paper, rice paper, or multilayer LDPE packaging with an environmentally friendly PLA lining.
Our design team is available to help you create the ideal coffee packaging. Plus, we are able to custom-print coffee bags using innovative digital printing technology, with a quick turnaround time of 40-hours and 24-hour shipping time.
MTPak Coffee also offers low minimum order quantities (MOQs) to micro-roasters who are looking to remain agile while showcasing brand identity and a commitment to the environment.