Bench Roasters: Small Batch Flexibility for Coffee Shops

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By Anne-Marie Hardie

Initially used for verification of samples in the cupping lab, the role of bench roasters has expanded with each new coffee wave. Sensors feeding data into sophisticated profiling software enable roasters to utilize these $2,500-10,000 machines to fully explore flavor possibilities in small batches prior to industrial production.

Accelerating sales of these machines is also due to the push for cafés to roast in-house. This is particularly true in Asia, but is expanding into North America.

“In a country like Korea, there are close to 1,000 bench roasters being used for production in coffee shops,” said Willem Boot, a well-respected consultant and founder of Boot Coffee in San Rafael, Calif. “The stores are small with limited amount of space, and this equipment creates the ambience of freshly roasted coffee,” he said.

In North America, consumers are eager to try exotic and single-origin coffees custom roasted in small batches, which makes an in-house smokeless bench roaster highly desirable.  “We are in the midst of almost an enhanced version of the third wave,” explains Shannon Chenny, lab director, Coffee Lab International in Waterbury, Vt. “Consumers are more educated and are actively looking for custom products, initially beer, wine and now coffee,” she said. These small roasters give cafés the ability to tailor the roast to produce exceptional coffees in limited quantities.

The machines are definitely more sophisticated, explains Boot. Bench roasters track rate of rise and automatically calculate development time ratios — data routinely used to design sophisticated roasting profiles and create new blends. “The conversation has become more about how they can play with roast profiles and test different roasting theories using a sample roaster,” said Alex Georgiou, head of marketing at Ikawa in London, England.  Developing new roasting recipes and blends using a bench roaster simply makes good business sense, said Boot. New technology that makes use of online resources and stored profiles, Bluetooth connectivity, optic temperature gauges and smokeless systems further expand the capabilities of these machines.

Examples of sophisticated bench roasters include the Probatino Tabletop, a solid drum roaster from Probat Burns that processes 8.8 lbs per hour using the same control and blending capabilities as a large-batch drum roaster in a space-saving configuration. The smallest batch roaster in the Diedrich IR series has a minimum capacity of 250g and delivers 8,000 BTU per hour. The machine weighs only 125 lbs.

Giesen Coffee Roasters in the Netherlands offers a precision in-store batch roaster with a capacity of 100 to 1,500 grams for selective roasts of exclusive beans. The W1 weighs 330 pounds (150 kilos) and fits into a 1 meter space. Coffee Lab International uses a Japanese-made 200g Fuji Royal bench roaster with cyclone. The IKAWA Pro installs anywhere, with no need for vents and packs into a Peli Storm Case. This 1500W roaster operates in Apple iOS with an app that can plot up to 20 temperature and 10 airflow points.

Fuji Royal, Tokyo

Fuji Royal, Tokyo

Roasts can be cooled within three minutes on this roaster by Fuji Royal, Tokyo

Roasting at the next level

One of the challenges for micro-roasters, shared Georgiou, is consistency. They depend heavily on the roasting expertise of a few key individuals. Technology helps fill the gap in expertise, by providing hands-free roasting with Bluetooth technology paired with online applications.

“The Ikawa Pro sample roaster can be programmed to follow the same curve on consecutive roasts to achieve standardized sample roasting,” said Georgiou. “Conversely, head roasters can also edit the roast profiles through the app to vary the roast when profiling coffee to find the optimal way to bring out the best of your green coffee of choice,” he said, adding, “There is still a benefit to hands-on experience, which is particularly true when adapting the cup profiles to a larger batch.”

When converting small to large batches “the roaster really needs to understand several variables including their green coffee measurements, bulk density, moisture, air temperature, air flow rate, and drum speed,” said Chenny. “A lot changes when the batch size changes, the system really needs to be monitored by the minute.” Close monitoring helps roasters understand how the coffee is changing and when to make the necessary adjustments after the initial cupping. Georgiou points out those variables such as roast time, end temperature, and even external factors, all need to be considered. “In terms of replicating the profiling roast to production scale, there is no magic formula – the key is a combination of data from profile roasts and the roast master’s skill and knowledge,” said Georgiou.  Hands-on training in creating cup profiles and experience with a variety of roasters under various conditions help provide a foundation of knowledge for converting readings from small batch profiles to larger roasts.

Roaster training at Coffee Lab International

Roaster training at Coffee Lab International

Roaster training at Coffee Lab International, Waterbury, Vermont

Hands-on evaluation

The best way to decide which equipment is best for your business is to simply try it, said Boot.

The Roasters Guild, which was founded in 2000 to promote and support the specialty roasting community, encourages roasters to practice their roasting skills on several different machines to determine which is best for their situation.

While roasting retreats, sensory summits, and cupping courses, like the ones offered at Coffee Lab, will help a roaster understand the unique characteristics of a green beans and best practices for roasting, it is hands-on experience that enables roasters to make the best choice for their business or brand.

The value of bench roasters, whether in large and small facilities, is evident. This equipment can elevate the quality of a company’s coffee and expand its reach to include highly coveted limited batches all the while exploring and coaxing the unique characteristics hidden within the bean.