11:40 Roast Taking 14:00 with Identical Settings on New Bullet R1

I dialed in an Ethiopia on my Bullet a few weeks ago using my first Bullet R1. The roast took 11:35 to reach 403 degrees. Today I’m trying the same profile on my newer Bullet R1 and it’s taking 14:00 to reach 403. I’m imagining a future where all of my roasts have to be dialed in twice. Once for each machine, and I have to have two recipes for every bean, and I definitely don’t want to do that.

I’ve done 3 roasts so far and they’re all turning out to be 13:30-14:00 minute roasts.

Preheat settings for both roasts were double checked.
Preheat: 455, F2, D9 for both roasters
Room temperature was 68 degrees
Exhaust Fan is always at 50% for both roasters
Both roasters have recently been cleaned

Any ideas what might be the culprit?

Here are the graphs for the two roasts

11:39 Roast

14:00 Roast on the other Bullet

I noticed that the preheat for the short roast was 464F and the longer roast was 455.
I don’t htink that is a big enough difference to add 2.5 minutes to your roast.

Do you know if your firmware versions are the same for both machines? The firmware could be controlling how much power is being put out to the induction board and induction coils. (I’m just guessing based upon some of the firmware changes that they have told us about)

Becuase the IBTS and the BT appear to be maintaining the same relationship for both machines, I think that we can rule out a bad measuring themal sensor.

Are you roasting these profiles with manual adjustments?
or playback? or a recipe?

An interesting conundrum.

Thanks for the thoughts!

Oh my goodness! I didn’t see that preheat was different. I have been doing some more roasts in the meantime, and I’m finding that I’m getting a longer roast now on both machines. anywhere from 13:00 -14:00. Even with a preheat of 464. I have no idea what is going on!

Roasting from a recipe. The changes are all temperature based so it is should be consistent across roasts. Is there any way this could be related to available power from the circuit box? For example, if the air conditioner kicks on, sometimes the lights dim very slightly in our house.

Not sure on firmware. I’ll look into it.

Yes, It could be related to available power from the outlet.

If you are experiencing a brownout or reduced voltage or are running an extension cord, that might explain why the Bullet is taking longer to run a recipe. (Extension cords can cause voltage drops)

If both Bullets are now taking 13-14 minutes, I would definitely be suspicious about the voltage.

You could try an early morning or late night roast and see if the roast goes back to your normal roast time. Only turn on one Bullet. No other major appliance should be on the same circuit.

Also: You should not be running Both bullets at the same time on the same circuit. That could definitely cause this problem.

Running the Bullets at reduced voltage can damage the bullet circuitry

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That’s really helpful! I haven’t run them both on the same outlet, but now I definitely won’t try.

You might have meant this when you wrote it, but it’s not just the same outlet.

A 110V bullet will draw rough 14 amps at full power, so you need to have them on separate circuits. Find your breaker box and make sure that the two outlets you plan to use don’t both switch off when a single breaker is thrown.

If you have 15A and 20A circuits, try to have the bullet on a 20A circuit and make sure you’re not running any big appliances, space heaters, hair dryers, etc while you roast.

You can get a Kill-a-Watt off Amazon for around $40 and it can help out quite a bit about troubleshooting power issues.

Per the NEC (the US electrical code) the maximum continuous current you should run on a 15 Amp circuit is 12 amps. At 120 V, this is equivalent to 1,440 watts.

For a 20 amp circuit it is 16 amps and 1,920 watts.

Circuit breakers are, at best, imprecise devices, so actual trip current may vary.


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PS - Circuit breakers are “Inverse time” devices. That means the greater the over current on the circuit, the faster the circuit breaker trips.

In the US, most household circuits use breakers with a Type C trip curve. That means that the breaker will trip instantly at currents of 5 to 10 times the breaker rating. Below currents of 5 times the rating, it will trip between 0.04 and 3 seconds, tripping quicker as the current approaches the 5 times mark,

Breakers feeding largish motor loads, such as HVAC units that have high start up currents, use a Type D trip curve. These trip instantly at 10 to 20 times the rating. Below currents of 10 times the rating, it will trip between 0.04 and 3 seconds, tripping quicker as the current approaches the 10 times mark,



strausal24opu, I note the power profile between the two roasts are entirely different. I’m guessing that you are making the power switches based on temp rather than time.

Try matching times with your power switches and see what time you end up at the desired color (dump temp).