Aillio Bullet: Everything You Need to Know

The Aillio Bullet is an induction-heated drum coffee roaster that handles batches from 150g up to 1.2kg (depending on the model). The drum itself is heated electromagnetically - similar to an induction hob - which gives it faster response times and more precise control than conventional electric heating elements. It comes with an infrared bean temperature sensor (IBTS), a front control panel for standalone operation, and RoasTime software for logging and profiling.

We stock the Aillio Bullet R2 and R2 Pro in the UK. This guide covers what the Bullet is, how the models compare, how to get started, the controls, the software, practical roasting tips, troubleshooting, and maintenance. (For broader roasting guidance, see our main guide on roasting coffee beans at home.)

The models compared

We currently stock the R2 and R2 Pro. The R1 V2 is included for comparison as it is still widely discussed in the community. We do not currently stock the R1 V2 - get in touch if you want to discuss availability or whether the R2 is a better fit.

Aillio Bullet R2 & R2 Pro

Precision drum roasters built for serious home roasters and micro-roasteries.

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Setting up for your first roast

Placement and ventilation

Place the roaster on a stable, heat-resistant surface with good ventilation. The Bullet produces smoke - particularly at medium and darker roast levels - so roasting near an open window or under an extraction setup is essential. Do not hard-connect a fan to the exhaust in a sealed system - this alters the machine's internal airflow and can affect the roast. Maintain an air gap between the exhaust and your extraction setup. (See  our guide on coffee roaster ventilation for practical setups.)

Connect the power cable and switch on. The control panel will display the current settings. Download and install RoasTime from aillio.com if you want to log your roasts - this is recommended from the start, as the data is useful even if you do not analyse it immediately.

Seasoning the drum

Before your first consumable roast, the drum needs seasoning. A new drum surface does not transfer heat as evenly as one that has been through several roasting cycles.

Run 3-4 roasts with inexpensive green coffee that you do not intend to drink. Aillio's FAQ covers the recommended protocol in detail. The general approach is to roast at moderate settings, letting the drum build up a light coating that improves heat transfer consistency. Do not skip this - your first few real roasts will be noticeably better on a seasoned drum.

Your first roast

Keep it simple. Use a mid-range, forgiving coffee - a washed Colombian or Brazilian works well because they give clear feedback and are not demanding to roast. Load around 500g so the probe is properly immersed in the bean mass.

Start with a moderate preheat - around 200-220°C on the IBTS - and charge the beans. Manage power, fan, and drum speed as the roast progresses. Listen for first crack, decide your target [roast level], and drop the beans into the cooling tray.

Your first roast is about learning how the machine responds - where the controls are, how quickly it reacts to power changes, and what the different sounds and smells mean. Cup the result, take notes, and adjust next time.

Understanding the controls

The Bullet gives you three main variables to manage during a roast.

Power (P). Controls the induction heating - higher power means more energy into the drum. The R2 Pro has 14 power levels, giving finer control at the upper end. The R1 V2 and R2 have 10 power levels.

Fan (F). Controls the exhaust fan speed, which affects airflow through the drum. Higher fan speeds remove more smoke and moisture but also pull more heat away from the beans. The R2 offers 12 fan speeds. Balancing fan speed against power is one of the key skills in Bullet roasting.

Drum speed (D). Controls how fast the drum rotates. The R2 offers 9 drum speeds. Faster rotation means more even heat distribution across the bean mass. Slower rotation means more conductive heat from the drum surface, which can be useful in the early stages but increases the risk of scorching if overdone.

Most Bullet users develop a rhythm: higher power and moderate fan during the drying phase, adjusting power down as first crack approaches, and managing fan speed through development to control how the roast finishes. The Bullet's responsiveness means you can adjust in real time based on what the IBTS and ROR are telling you.

IBTS (Infrared Bean Temperature Sensor). This is the Bullet's primary temperature reference. Traditional probes measure a combination of bean temperature and ambient air. The IBTS uses infrared to measure the actual surface temperature of the beans, which gives more accurate and repeatable readings. Use the IBTS as your main guide - the traditional probe is useful as a secondary reference.

Standalone operation. The Bullet can be operated from its front control panel without a computer connected. You can adjust power, fan, and drum speed directly on the machine. Connecting to RoasTime adds detailed logging, profile replay, and community features - but it is not required to roast.

RoasTime and Roast.World

RoasTime is Aillio's free roasting software. It connects to the Bullet via USB and provides real-time display of bean temperature (IBTS), drum temperature, ROR, power, fan, and drum speed. Every roast is logged automatically, building a library you can refer back to.

Key features include profile replay (follow a previous roast's settings automatically), profile overlay (compare multiple roasts visually), and the ability to mark events during the roast (first crack, drop, etc.).

Roast.World is the community platform connected to RoasTime. Users share roast profiles with details about the coffee, the settings, and the results. If you are roasting a coffee and want to see how others have approached it, searching Roast.World is a practical starting point. You can download profiles and load them into RoasTime as a starting reference.

RoasTime runs on Mac, Windows, and Linux. The R2 Pro also supports direct integration with Cropster and Artisan for users who prefer those platforms or who need to transfer profiles to production roasters. (See coffee roast profiling: from sample to production for how to translate profiles between machines.)

Practical roasting tips

Batch size matters

The Bullet is sensitive to batch size. A recipe developed for 500g will not produce the same results at 800g without adjusting power, fan, and drum speed. If you are following someone else's profile from Roast.World, check what batch size they used - and adjust if yours is different. Start by finding a batch size that works for your consumption and stick with it while you learn the machine.

Preheat consistently

The Bullet performs best when preheated consistently between roasts. If you are doing back-to-back batches, let the machine stabilise between charges rather than rushing. The IBTS reading should be steady before you drop the next batch.

Keep the chaff filter clean

On the R2 and R2 Pro, the FlowSense system will alert you when airflow is restricted. On the R1 V2, check and clean the chaff filter manually between roasts. A blocked filter restricts airflow, affects roast consistency, and can cause off-flavours. Clean the filter every 2-3kg of roasted coffee as a minimum.

Ventilate properly

The Bullet produces meaningful smoke, especially at medium and darker roast levels. Position an extraction hood or fan near the exhaust with an air gap - do not create a sealed connection. (See our guide on coffee roaster ventilation for detailed setups.)

Cup everything

The Bullet gives you excellent data - but the cup is the final judge. Cup your roasts systematically, compare different profiles of the same coffee, and use the data to understand what worked and why. (See our guide on coffee cupping for how to set up a cupping at home.)

Troubleshooting

Common error codes

A-01 / A-08. Usually linked to exhaust fan or airflow issues. Check for a loose impeller, a dirty chaff filter, or run a fan calibration if the speed drops below 400 RPM.

A-02. Triggered by the safety deadman's switch. Inspect internal connections and ensure components are cool and properly seated.

ErC codes (eg ErC 0256). These point to internal board or sensor communication failures. Check that your input voltage is stable. If the issue persists, contact support - it may be a power induction board failure that needs professional attention.

RoasTime connection issues

If RoasTime disconnects or will not recognise the roaster, unplug both the power cable and the USB cable, close the RoasTime software, then plug everything back in and reopen the software. Check that your computer's system permissions allow RoasTime to access the USB connection.

Roaster fails to start (all fans at max speed)

This can happen if the roaster has lost its firmware. Follow the manual bootload procedure in Aillio's documentation. If you are not comfortable doing this yourself, get in touch and we can help.

Smoke or leaking oils

A clogged chaff filter or dirty exhaust impeller restricts airflow and causes smoke to back up into the roasting environment. Clean the chaff filter every 2-3kg of roasted coffee. If the impeller is heavily soiled, soak it in an espresso machine detergent solution, rinse thoroughly, and dry before reinstalling.

The roast tastes flat or baked

If your coffee lacks sweetness and tastes papery or hollow, the roast may have lost momentum - particularly around first crack. Check your ROR through the development phase. If the ROR crashed or stalled, the roast has baked. Maintain enough power going into crack to keep the roast progressing smoothly.

The roast is darker than expected

Check your batch size - a smaller batch than the profile was designed for will roast faster and darker. Also check your preheat temperature. If the IBTS reading at charge is higher than intended, the roast will progress faster from the start. Reduce preheat by 5-10°C and compare.

Choosing between the R2 and R2 Pro

Choose the R2 (£3,500) if:

You want a capable, well-featured Aillio Bullet without the premium of the Pro. The R2 adds FlowSense, Chaff Filter Alert, QuickClean magnetic assembly, and improved induction heating and airflow compared to the R1 V2. It handles 150g-1kg batches and is well-suited to regular back-to-back roasting - the improved heat management means less profile drift between consecutive roasts. For most home roasters and many small commercial users, the R2 delivers everything you need.

Choose the R2 Pro (£4,550) if:

You want maximum capacity, control, and stability. The R2 Pro adds 1.2kg batch capacity, 14 power levels, a barometric pressure sensor for altitude compensation, the automatic bean agitation cooling tray, a higher-resolution hybrid OLED panel, and Cropster/Artisan integration. It is designed for production-level work - micro-roasteries, QC programmes, development roasting, or heavy daily use. If you plan to build a business around this machine, the Pro is the one to buy.

The upgrade path

Many Bullet users start with an earlier model and upgrade when they want more capacity or features. The Aillio Bullet has strong resale value - typically around 70% of the original purchase price - so upgrading is less costly than it might seem.

Using the Bullet as a sample roaster

The Bullet's minimum batch of 150g and its precise temperature control make it usable for sample roasting, though its sweet spot is production rather than evaluation. If you are primarily evaluating green coffees in small quantities, a dedicated sample roaster like the Kaffelogic Nano 7 (which handles batches as small as 40g with the BOOST Kit) may be more practical.

Where the Bullet works well for sampling is when you want to evaluate a coffee at a batch size closer to your production volume. Roasting a 300-500g sample on the Bullet gives you a more representative result than a 50g sample on a fluid bed roaster, because the heat transfer mechanism and roast dynamics are the same as your production batches.

Maintenance

Chaff filter. Clean every 2-3kg of roasted coffee. The R2 and R2 Pro will alert you via FlowSense when it needs attention.

Exhaust impeller. Check periodically for oil build-up. If soiled, soak in espresso machine detergent solution, rinse, and dry before reinstalling.

Drum and front plate. The R2 and R2 Pro use QuickClean magnetic assemblies - the front plate comes off easily for access to the drum interior. Clean periodically with a dry cloth. Aillio's FAQ provides detailed guidance on deep cleaning frequency.

IBTS sensor. The infrared sensor window can accumulate residue over time, which affects accuracy. Clean it gently with a soft cloth when you notice readings becoming inconsistent. The QuickClean design on the R2 and R2 Pro makes accessing the IBTS straightforward.

Cooling tray. Empty and wipe down after each session. On the R2 Pro, check the automatic agitation mechanism periodically to ensure it moves freely.

Firmware. Update through RoasTime when prompted. Aillio regularly releases firmware improvements that enhance performance and add features.

Wrapping up

The Aillio Bullet is simple to get started with and deep enough to grow into. Your first roast after seasoning - 500g of a forgiving washed coffee, moderate preheat, listening for crack - will teach you how the machine responds. From there, experimenting with power, fan, and drum speed, connecting to RoasTime, and exploring profiles on Roast.World opens up a level of control that most home roasters do not get without spending significantly more.

If you are considering one and want to talk through which model suits your situation, get in touch. We stock the R2 and R2 Pro, we roast on them ourselves, and we are happy to help you decide.