Bullet R2 Pro – Managing Tipping in 1-1.2kg Batches

R2 & R2 Pro Specific
1

Hi everyone,

I’ve been experimenting with the Bullet R2 Pro for about a month and wanted to start a discussion on the best approach for roasting 1-1.2kg batches.

I’m bringing this up because I’ve encountered some tipping issues and want to raise awareness within the community.

My Experiments:

  1. First Attempt (1.2kg Batch)
  • Charge Temp: 300°C
  • Initial Power: P13
  • Initial Fan: 3
  • Drum Speed: 9

I followed an approach similar to gas roasting—gradually reducing power while increasing the fan until first crack (9:10), then further reducing power afterward. The total roast time was 11:19, with an end temp of 217°C (which I find quite high). The graph looked great, but under UV light, I noticed tipping throughout the batch.
2. Second Attempt (Same Parameters, Closer Monitoring)

  • I repeated the roast while checking the beans every 5-10 seconds with the tryer.
  • I discovered that tipping occurred around 170°C, roughly in the middle of the roast.
  1. Third Attempt (Adjusted Approach to Prevent Tipping)
  • Charge Temp: 265°C
  • Power Level: P12
  • Fan: 5
  • Drum Speed: 9

This time, I kept the fan at 5 until around 170°C and gradually reduced power to P9 before reaching that point. This adjustment eliminated the tipping issue but slowed down the roast. First crack occurred at 10:36, and the total roast time extended to 13 minutes.

Next Steps:

My next experiment will focus on increasing the charge temperature and power to shorten the drying phase while still avoiding tipping.

Now, I’d love to hear from you! What’s your experience with larger batch sizes, and how do you approach them?

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2

Hello,

It sounds like you have done a wonderful job in identifying and mitigating the problem. I’m writing only to share that I also experience tipping on my R2 Pro, but with smaller batches of 450g and a power level that never goes above P9 for pre-heating and quickly declining to P5-6 throughout the roast.

Following the traditional wisdom on avoiding tipping from Rob Hoos, I increased my airflow to F5 from the beginning of the roast and kept it there to the end. The only change I make to airflow is to ramp up the fan to F12 right before dropping the beans to get as much of the chaff out as possible before dropping. Otherwise, the continual higher fan speed made a difference in minimizing tipping.

There are still some roast defects from time to time, like light scorching on some of the beans (presumably from the hot drum, even though the drum is always at D9). I’m still figuring out the machine and its (or perhaps my) idiosyncrasies.

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3

I had to Google it. Tipping is when the ends of the coffee bean get scorched or burnt. I thought I’d save everyone else the detour. :slight_smile:

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4

what origin of beans are you using?
I have found that the fan is really strong. To avoid tipping i do a much lower charge temp than you, treated more like a gas roaster. adjust drum speed to a 6-7. D9 is like 70+ per minute in my opinion is unnecessary. keep the fan at f2 or below until around 280 fahrenheit. Your power is good to go. Make adjustments right before yellow and a few a few mins before FC.

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5

This comes from a R1 V2, but should apply to the other models as well. I roast 1.05Kgs at a time and faced some tipping issues earlier. Now my roasting regimen includes a soak at P2 and that has mitigated the issue. I have set the default P to drop to P2 immediately after I drop the beans (Roasting has started prompt). At turnaround, I increase the P to max (9 in my case) and then take the roast forward.

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6

Hi everyone,

I work with different origins, but for this specific test, I was roasting a washed Colombian Caturra. I’ve resolved the tipping issue, which can occur at any stage of the roast. In my case, it was happening during the Maillard phase.

In my opinion, the charge temperature should be as high as possible. While IBTS readings may seem high, they are still within the expected range for a gas roaster—even at 300°C IBTS—when compared to bean temperature. I haven’t experienced scorching at the beginning of the roast, even with a 300°C setting, including when roasting naturals.

Tipping can occur at different stages depending on the bean variety. For example, when roasting a natural Gesha or Pacamara, I would be especially cautious with power adjustments right after yellowing.

Would love to hear your thoughts and experiences!

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