Probat releases updated sample roaster

A sample roaster has many uses. Industrial-sized roasters carry out constant quality control, green coffee traders sample countless coffees per week, and some producers are even able to test their harvests. More  smaller specialty roasters also require a machine capable of tiny batch sizes to develop various profiles for different coffees.

To meet the needs of these various markets, Probat started from scratch with the development of a new sample roaster just as adept as its larger shop and industrial models.

Jens Roelofs, Head of Sales and Service for Shop Roasters at Probat, tells Global Coffee Report demand has increased for sample roasters and for what they’re capable of.

“As always, roasters are looking for consistency and reproducibility in their roasts. Now, they’re also looking for greater flexibility when it comes to creating new profiles,” Roelofs says.

“We have been seeing the increase in lightly roasted and specialty coffees, which are quite costly when it comes to the purchase of green bean. Roasters don’t want to waste too much of this expensive coffee, so they need a device that roasts really small batches to get an idea of how they should approach roasting more on a larger machine.”

Launched in June 2019 at World of Coffee Berlin and first reaching customers last December, the Probat sample roaster can roast batch sizes from 150 to 200 grams in three to 20 minutes. The compact machine sits at 25 centimetres wide and only just over half a metre tall and deep.

Probat Head of Product Management Andreas Rinke says the German manufacturer’s biggest technical accomplishment with the sample roaster was introducing convection heating into such a small system.

“We took what we’d done in our larger roasters, primarily with the Probatone shop roaster line, and scaled it down to a small size capacity,” Rinke says.

“We wanted to design a physically smaller roaster with all the functionality of the bigger models. Simply reducing the size would compromise on this, so we had to find other ways to implement these features.”

An electric hot air unit generates heated air which is used to roast the coffee, rather than contact with a hot surface.

“The high-performance electrical heating of the sample roaster improves the system of our previous model, providing the operator with flexibility with their roasts and supports any ideas they might have while developing their coffee,” Rinke says.

“While the machine and batch size become smaller, individual beans remain the same size. Maintaining a reasonable airflow to get enough heat to the bean and remove chaff was only possible thanks to access to new parts and components.”

The design of the sample roaster also took usability into account. Several sample roasters can be installed side by side and share external equipment such as cyclones. In terms of safety, the unit complies with regulations and features full casing with low heat conductivity, reducing surface temperature. Roelofs says the machine was also kept simple to operate.

Beans are loaded in the drum and the operator decides how much energy and heat to use in the process. A sampler lets them monitor the beans during roasting. Once the roast is complete, beans are discharged into a cooling tray where constant airflow cools them down.

Information on these roasts is collected and stored using Probat’s software, which can be accessed later or transferred to larger models.

“Customers are looking for more control over the roasting process. This means they need more information and data collected from a roast,” Roelofs says.

“Old sample roasters were manually operated. You had a thermocouple and that was it in terms of control, data collection, or information. This new sample roaster features a control system which saves history data, can show, store, and recall profiles, and analyse it and all the data from the roasting process afterwards.”

These controls will be installed in every new Probat model from the sample roast up to the 25-kilogram shop roaster.

“We’re going to use the same software and hardware concepts for all of these roasters, meaning they are compatible with each other and can exchange data,” Rinke says.

Collecting this data from the roaster provides an opportunity for the operator to make a “more sophisticated” analysis of their coffee roasts.

“Many customers are taking a scientific approach to developing profiles. It’s not that old craftsmen [on-the-fly] style of roasting anymore. It’s more data-related and structured,” Rinke says. “Roasters also want to differentiate themselves from others. They want to get the best out of the green bean, and we help them as much as we can with the data and support we provide.”

The user interface of this software was optimised through consultation with a wide variety of Probat’s customers.

“We visited some of our customers and talked to them to see how they operate their machines day in, day out. This gave us input into what our customers think is important in a user interface,” Rinke says.

“There is also the possibility to connect any third-party device with a browser to the roaster. This allows you to operate the machine remotely and view current roast, recipes, history, batch protocols, and so on.”

Roelofs says the new features of the sample roaster have been particularly appealing, but not limited, to the specialty market.

“There is a certain interest from customers that were not looking for a sample roaster before due to the limitations that old models had,” he says. “Though we didn’t put a focus on any one market while developing the sample roaster. The idea was to produce a unit that was easy to use for any type of customer. We also sell sample roasters to some customers who have only just stepped into coffee, and it can act as an entry way into roasting.”

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