Rapid pre-roast warm up and smart warm up temperature idle

With one simple touch on the button, all Rubasse roasters can perform warm up protocols and reach your desired temperature within 5 minutes. (manually warming up traditional drum roasters might take you more than 30 minutes)

Also, before roasting and between different roast batches, our roasters can idle at your selected temperature with precision for any designated duration.

Together, the smart warm up function and our automated roasting system enables hyper-efficient roasting on all Rubasse roasters.

Automated Functions Throughout Roasting

From roaster warm up to post-cooling unloading, our automated roaster functions have you covered:

Step1:Auto-charging after completing warm up

Step2:Fully automated smart roasting, following your selected roast profile by automatically adjusting heat application, airflow, and drum rotation speed.
 

Step3:Auto-discharging after reaching desired end point on the selected roast profile

Step4:At the same time, the roaster will start its auto-cooling procedure. The cooling duration can be set to your liking.

Step5:Auto-unloading the roasted coffee after cooling is completed.

Rubasse PID Backtracking profile replication algorithm

When simply following and reproducing power and airflow settings from previous roasts, the temperature curves might look nothing like the desired profile.

But our profile replication algorithm does more than just reproducing your previous heat application settings – it can actually compensate for the temperature deviations and adjust the heating settings responsively.

Besides roasting temperature compensation, our profile replication algorithm also tracks and follows the roasting systems underpressure profile of your previous roasts, enabling more accurate roast replications.

Why use infrared radiation?

Near infrared radiation(NIR) has the ability to penetrate up to 1cm under the surface of grain products

By choosing NIR as the primary method of heating, our roasters can easily roast the coffees more evenly, creating a cup profile that is clean, transparent, and vibrant, fully showcasing the flavor potential and terroir of each and every coffee.

Rubasse's Heating Halogen lamp:

One of the most important aspects when designing a NIR-based heating element is the selection of NIR wavelength. Rubasse roasters all have an NIR heating lamp that emits radiation energy having wavelengths between 750 nm to 1500 nm. Infrared energy lying in this area had been proven to be better absorbed by grain products (Zhongli, 2010).

Rapid heat response:

Unlike typical electrical coffee roasters, our NIR heating technology enables powerful and ultra-responsive roasting comparable (if not better) than gas-powered roasters. Center placement NIR heating really is like harnessing the best of both worlds: the power and the responsiveness of gas burners combined with the precise linear heat adjusting abilities of electric heating elements.

Power adjustments: Linear, precise control simply achieved by altering the input wattage.Rapid heating: ultra-responsive power adjustments, corresponding temperature and rate of rise changes can be observed within 3 seconds (fastest scenario).

During roasting, all models of Rubasse roasters can record the curves of the different sensors, and real-time plotting of the curves will be shown on the touchscreen panel used to control the different roaster settings.

Together with our responsive heating technology, this integrated design enables straightforward and intuitive control during every single batch of your roasts.

Settings you can alter:

power, airflow fan speed, drum rotation rpm

Data recorded:

Power settings, Airflow fan Speed settings, Drum rpm settings, Bean temperature readings, Exhaust air temperature readings, Drum temperature readings, Rate of Rise, Calculated amount of released moisture, Differential Pressure readings(underpressure of roasting system), Turning point, time and temp. of first crack, time and temp. of second crack, end temperature and roasting duration.

Exchangable data:

The data profile recorded can be exported or imported via USB connection. Roast profile data can be shared between all Rubasse roasters of the same model.

Artisan compatible

Our roast profiles are recorded in CSV format files, and can be opened(but not recorded) using Artisan (version 2.6.0 or above).

Actual layout of the touchscreen panel during roasting:

Unique airflow design for maximum heating efficiency:

As shown below, our roaster’s airflow is designed in a way that the cold air would first be forced through our NIR heating element before entering the roasting chamber, where the heated air would be used to help distribute the roasting energy more evenly throughout the roasting coffee.

Linear airflow control using variable frequency drive fan motors:

As many roasters have experienced, airflow stability can have a profound impact on the final flavor of roasted coffee. Our linearly adjustable airflow ranges from 25% to 140%, and by altering the fan motors rotation speed, one can make airflow adjustments with precision up to 1%, giving a total of 116 different airflow settings within the whole range. This kind of adjustability enables our users to have total control over airflow during every batch of roasting.

Linear relation between airflow setting percentage and actual volume flow rate of exhaust air as demonstrated above.

Chaff collection:

A well-functioning chaff collection system is a crucial factor contributing to a roaster’s ability to do back-to-back batch roasting. No matter the designated batch size, all Rubasse roasters are equipped with cyclone chaff collecting systems, efficiently separating chaff and dust from the roaster’s exhaust air. Together with our designed quick release chaff collection bin, cleaning and maintenance during and after roasting is a breeze for our users.

Double-Wall Stainless Drum

304 stainless steel Double-wall design, having insulation properties similar to a thermos bottle.

Combined with the center placement of our heating element, this design largely improved the efficiency of energy usage on all our roasters.

Unique roasting drum - resonant cavity-like design

The heat energy emitted from the center-placed NIR heat element will: a. heat up the coffee beans directly,

b. first be reflected from the drum’s inner surface then heat up the coffee beans, c. heat up the roasting drum, and d. heat up the air within the drum.

And due to the combination of our heat source and drum design which creates a roasting environment that resembles a resonant cavity,

the heat “trapped” within the roasting drum will eventually trend toward the coffee beans that has the lowest temperature within the drum.

A fully loaded 3kg Rubasse micro roaster reaching a peak ROR of 36°C/min.

Superb heat retention ability:

Utilizing the fact that NIR radiation do not penetrate stainless steel easily, together with the double wall design,

the majority of the energy emitted from the heating element is “locked” within the roasting drum.

Besides the obvious benefit being increased heating efficiency,

another advantage is the improved comfort regarding the roasting environment – Long gone are the hot and sweaty production days!!

The outer surface of the roaster’s roasting chamber remains at 40°C while roasting with a bean temperature reading of 200°C.

Notice that the room temperature easily stays below 26°C.

The double wall stainless steel drum design, resembling that of a thermos bottle.

Bidirectional drum rotation:

Here at Rubasse we thrive to utilize all energy as efficiently and stably as possible,

hence the unique design of the bidirectional drum – when roasting, the drum rotates in a counterclockwise direction,

pushing the coffee backwards towards the spot where the just-heated airflow enters the drum, increasing convective heating efficiency;

when discharging, the drum rotates in a clockwise direction, pushing the coffee forwards into the cooling tray.

What we measure in our roaster: bean temperature, exhaust air moisture content, roast chamber differential pressure, drum temperature, and exhaust air temperature.

Bean Temperature Probe:

measuring the temperature within the bean pile.

Our K type thermocouple is made from carefully selected wires and is tailored to our needs. Within the typical coffee roasting temperature range, it can reach an accuracy of +-0.1°C.

Also, the shape design of the temperature probe and the possibility to make fast, accurate heat and airflow adjustments allows users to roast as low as 200g even on the 3kg machine, giving you much more flexibility regarding roasting batch sizes on our roasters.

Exhaust Air Moisture content:

reflecting the amount of moisture being released from the coffee while roasting.

One of our exclusive functions is the ability to record “real-time released moisture content” data in our roast profiles. This function is based on sensors that detect real-time exhaust air moisture content, and this data can be used to calculate the real-time released moisture content value which our roaster displays and records in the roast profiles. With this data, our users can gain more insight into what changes are actually occurring when coffee is being roasted.

Differential Pressure Meter:

a more precise measurement for actual exhaust airflow

The pressure difference between the roasting drum and the surrounding environment can reflect the actual amount of airflow during the roasting process. As many might already know, the amount of airflow during roasting is one of the crucial factors that affects the final cup profile. By measuring and showing the differential pressure, users can utilize this information in combination with the fully linear airflow control to perform much more precise and informed airflow adjustments on our roasters, giving you unprecedented controllability and ease of use.

Drum Temperature Sensor:

measuring the temperature of the drum’s inner surface

Roasters probably are familiar with some roasting defects related to an overheated drum (e.g. scorching or excessive oiling on the bean surface). When roasting, it is crucial to make sure that the temperature of the roasting drum is within a “safe” range so it won’t sabotage the final flavors within the cup. In our roasters, we have a customized infrared temperature sensor that monitors the real-time temperature of the drum’s inner metal surface, enabling roasters to know more about the actual roasting environment and have better control overall.

Exhaust Temperature Sensor:

measuring the temperature of air leaving the roasting chamber. 

Exhaust air temperature is a temperature measurement that is closely related to the air temperature within the roasting chamber, hence it is also highly related to convective heat transfer during roasting. Adding the exhaust air temperature reading to our roasting data and monitoring it in real-time can be tremendously helpful when adjusting and balancing airflow and heat settings when roasting.

Direct heating of the coffee beans via radiation emitted from the NIR heating element.

By placing the NIR heating element right at the center of the roasting drum, we greatly increased the efficiency of energy usage and responsiveness of heating during roasting.

Also, unlike some other electric heating methods, NIR heating technology is responsive by nature. Heat energy emitted from the NIR bulbs can reflect changes in input power almost immediately, so unlike the common impression of needing to account for the “lag” when changing heat settings, controlling our roasters relies much less on predictions and guesses.

Increasing heat to 30%: rate of rise reacted within 3 seconds. Note that here we are roasting a full 3kg batch on our 3kg Micro roaster which has a 220V, 6000W NIR heating element.

Increasing heat to 100%: Again, rapid changes occured for the rate of rise within 3 seconds.



 

Cutting off heat: rate of rise drops almost immediately.

Cranking up the heat to 100% again: rapid increase in rate of rise observed.

The responsiveness in our roaster’s heating technology not only gives our users more freedom and control over heat application, but also it is actually a key cornerstone to our Autopilot profile replication system.

Our Electric Roasters: None of the potential gas fuel related dangers.

Preset limit for warm-up and charging temperature setting.

The preheat limit being set at 260°C acts like an additional safety measure, preventing operations that might result in an overall system temperature that exceeds the safety limit.

When the Bean Temp. readings exceed 260°C, the system automatically cuts off the heat supply

While roasting, if the bean temperature reading reaches 260°C or higher, the coffee beans might already start to carbonize. During such occasions, our roasters are programmed to automatically shut off the heat supply.

When the system Detects Abnormally High Temperature Readings, the Overheating alarm will be set off, and the control over all functions will be taken over by the system’s safety protocol. 

Ultra-high bean temperature (factory set at 300°C): During such occasions, control of heat supply, airflow fan speed, and drum rpm will all be taken over by the roaster’s smart control system for fire-prevention, and also the roaster’s alarm will be set off.

Roasting one 3kg batch on the Rubasse micro 3kg roaster only uses 1.1 kWh of electricity.

On the other hand, though actual numbers may vary from roaster to roaster, the average gas consumption of roasting a 3kg batch on liquefied petroleum gas-powered roasters is around 0.25kg. Under Taiwan’s energy prices (July 2022), the estimated cost for roasting one 3kg batch on Rubasse roasters and LPG-powered roasters are 1.8ntd and 10ntd respectively. These numbers indicated that the cost for energy when roasting on our roasters is only 18% of what the typical cost may be when roasting on more traditional machines.

Low carbon emission

By estimation, when roasting the 3kg batches on Rubasse roasters, the carbon emission is around 0.55kg per batch; on the other hand, traditional gas-powered roasters may emit around 0.78kg per batch. The cut down in carbon emission after switching to Rubasse roasters is around 30%.

Drastically cutting down waste heat during roasting

The total heat energy generated while roasting a full batch on our 3kg roaster is around 946Kcal, and by calculations based on LPG usage, the heat energy generated during roasting on a more traditional 3kg gas-powered roaster is around 3000Kcal (assuming complete combustion of the fuel gas). These numbers indicated that Rubasse roasters are much more efficient with the task of roasting and bringing 3kg of coffee beans to the desired temperature. This also means that our roasters likely emit much less waste heat (namely 2054Kcal less per 3kg batch according to the numbers here) into the surrounding environment during the roasting process, which means less air conditioning needed and a more comfortable roasting environment.

Actual comparison between Rubasse roasters and gas-powered roasters

(roasting 3kg batches).