Pre-Heating the Behmor Coffee Roaster: What to Know About Warming Up Your Machine

Our guide to pre-heating vs. not pre-heating the Behmor coffee roaster and what to expect.

A topic that comes up a lot with Behmor owners is whether or not to pre-heat the machine before roasting. Some say it improves cup flavors, others call it a waste of time. One thing’s for certain is that it shortens the overall roast times, which will have some impact on the cup.

After spending some time testing the thresholds on an upgraded 1600 Plus (same features as a 2000 AB Plus), and speaking to Joe Behmor himself on this topic, we’ve compiled a list of answers to some commonly asked questions below that we hope will help you decide whether or not to add the extra step of pre-heating your Behmor your coffee roasting regimen.

Pre-heating basics – things to know:

What does “pre-heating the Behmor” mean?

Pre-heating any roaster simply means warming up the machine by starting a roast cycle without coffee. Most production roasters require a pre-heating period for warming internal parts, which often includes a steel roasting drum that takes a while to come up to temp. For the Behmor, it’s a way of “waking up” the roaster, affording you a bit of a running start.

Do I have to pre-heat the Behmor to get a good roast?

Absolutely not! All of the Behmor roaster models are more than capable of producing great tasting roasts without pre-heating the machine. Pre-heating the Behmor is one way of shortening your overall roast time. Whether or not you do so should be based on personal preference.

What’s the safest way to pre-heat the Behmor?

Before starting the pre-heat cycle, I remove the drum from the roast chamber and pre-load my roast batch. I warm up the Behmor with the chaff tray only, starting the roaster in manual mode on the highest heat setting of <P5>. When the Behmor reaches the desired pre-heat temperature (monitor the roast chamber thermistor by pressing the <B> button), I stop the roaster, remove the chaff tray, insert the pre-loaded drum and re-start my roast as normal.

checking the roast chamber temperature while pre-heating the Behmor coffee roaster
checking the roast chamber temperature while pre-heating the Behmor coffee roaster

Is this pre-heat cycle dangerous?

No, not really. The inside of the roaster will be hot, so take care pulling the chaff tray and loading your wire grid drum so as to not burn yourself. I use gloves or a towel to manage the hot chaff tray. You can also remove the chaff tray before warming up the machine, but the cold metal will cool down the roasting chamber some when loading into the hot machine.

How does the pre-heat cycle affect roast dynamics in a Behmor?

Depending on how long you warm up your roaster, you can shave a minute+ off your roast time. It may not sound like much, but it can certainly improve cup dynamics if that’s the sort of flavor profile you’re after.

How hot can I safely warm up the roaster?

Most Behmor coffee roasters can be pre-heated to 250 F, or somewhere around 3 – 4 minutes. (On my upgraded Behmor 1600 Plus, 3 minutes on the highest heat settings gets me to 200 F).

What happens if I try to pre-heat the roaster beyond 250 F?

Pe-heating your Behmor past 250 F forces you to run the cooling cycle before starting another roast. Obviously, this defeats the purpose of warming up the machine! One thing to keep in mind is that electrical heat continues to ascend after switching it off. This means you need to stop the pre-heat cycle before your Behmor hits 250 F so that you don’t pass the safety set point threshold.

Will pre-heating the Behmor harm the roaster?

No, pre-heating the Behmor shouldn’t have any negative affects on the roaster’s internals as long as you re-start your roast. If you decide not to start your roast, make sure to run the cool cycle in order to cool the roaster down completely.

The Behmor wire grid drum used across Behmor platforms
The Behmor small grid drum used across both 1600 and 2000 iterations of the Behmor coffee roaster.

How will pre-heating affect the cup flavors?

In general, a faster roast leads to a more dynamic cup profile. There is such a thing as roasting too fast, but you won’t have that problem with the Behmor. Setting out to roast faster should coincide with roasting light. Coffees that can benefit from this roast style are those with potential for acidity and top notes, like African coffees and Geshas for example. Roasting these coffees too dark will mute much of what’s special and interesting, as will roasting them too long.

Are there coffees that benefit from not warming up the Behmor?

I would not pre-heat my Behmor for softer, low density coffees. They will benefit from less aggressive heat application, the slower roast progression helping to develop sweetness without risking the roast getting away from you. These tend to be lower altitude coffees grown below 1500 meters, like Brazil and many of the coffees in El Salvador and Honduras. Also, if you’re roasting blends, or roast dark in general, I would also skip the pre-heat step.

In short, whether or not you pre-heat your Behmor is really up to you and will depend on what you’re hoping to taste in the cup. If you want to highlight top notes and acidity in a light roast, I say give it a shot and see if you can taste the difference. Especially if you’re not getting the dimension that you’d hoped for. But if it’s the deeper bass notes of a dark roast that you’re after, pre-heating the Behmor is unlikely to produce any discernible difference.

Pre-heating is only one way of shortening your roast times. If you’d like to learn more about our approach to light roasting in the Behmor coffee roaster, check out this blog post.

If you’re interested in getting a nice dark roast in your Behmor, here’s a list of our recommendations.

12 Responses

  1. Which is it? In this article, “starting the roaster in manual mode on the highest heat setting of .”
    And in the Dark Roast article, “On their own, they won’t generally allow enough time for coffee to reach 2nd crack, even using P1, the highest heat setting”

    So P5 or P1?

    1. Thanks for pointing that out! In the dark roast post, I should’ve written “on P1, highest preset roast profile”. The P5 setting in manual mode is burner on 100%, and the hottest possible setting in the Behmor. I’ve updated the dark roast post and hope that clears up any confusion.


  2. I roast with a Gene Cafe drum roaster; never-the-less, I find I get more consistent and repeatable roasts with a pre-heat cycle.

    1. That’s interesting to hear Bruce. I honestly don’t have that much experience myself with the Gene, but will try pre-heating out on that machine next attempt. Care to share your method?

      Thanks for the note!


  3. I used to preheat with the basket and chaff tray in the Behmor. Handling the hot basket was much more difficult. So now I preheat with the basket out, for 2:50. Then if I pull the chaff tray out with mitts, I can put the basket in bare-handed, which is much easier. I find preheating allows me to more comfortably slow down the roast as we go into first crack.

    1. I used to do the exact same thing and took me a few burned fingers to realize that I could just keep the drum outside during the warm-up. Haha. That’s an interesting note of having more control during 1st crack with a pre-heat cycle, and I have no explanation for that. I would think that a faster rate of rise would have the opposite effect, but sounds like that’s not the case for you.

      Drum speed might also help with controlling 1st C to some degree depending on batch size. We use the fast drum speed through the drying phase at the very least to keep the coffee high in the drum and closer to the heating elements. Perhaps slowing the drum speed once the beans become exothermic could lead to a faster 1st C if the bean bed were large enough….haven’t tested that.

      Here’s an older blog post and video Tom did on roasting with the 16 vs 32 rpm drum speeds when Behmor first upgraded the motors.

      Behmor Coffee Roaster Drum Speed Comparison

      Thanks for chiming in on the thread!


  4. Thanks for the update on preheating Dan. I received a 2000 AB as a gift recently after roasting on a 1600 plus for years. So far the biggest difference seems to be noise volume from exhaust fan and drum speed motors. Both a good bit louder. My first couple of roasts were not my usual results. It seems the faster, louder drum roll and exhaust fan threw me off a bit. Hearing 1C took some getting used to the new dynamics. Since the upgrade in drum speed ( 16 to 32 rpms ) is one of the 2000 ABs developments, I wanted to hear your input on how best to use the additional drum speeds. Thanks

    1. Hey Steve,

      That’s interesting about the motor and fan noise. I need to go back and look at the specs on the 2000 AB, but didn’t think the exhaust fan changed. I only have 1600 Plus Behmors that I upgraded with the new motor and control panel. Whatever the case, I’m glad to hear you’ve been able to adjust to the 2000 AB, and hope you’re happy with roasting capability.

      On drum speed, we’ve been using the faster drum speed to keep the coffee higher in the drum, and closer to the heating elements. Keeping the coffee physically closer to the heating elements should make for a faster rate of rise. The only exception I can think of is when the beans become exothermic at 1st C. I would think slowing the drum speed with a larger bean mass would cause a more rapid 1st C.

      Here’s an older blog post and video Tom did on roasting with the 16 vs 32 rpm drum speeds when Behmor first upgraded the motors.

      Behmor Coffee Roaster Drum Speed Comparison

      Thanks again for your comment and question!


  5. Hello Dan,

    Thanks for the post. Your posts and comments are very informative. I have roasted with Behmor around ten times, and I love the machine! Before this, I had roasted coffee on the stovetop, but Behmor is much easier and much more consistent.

    I’ve been using the suggested profile for my city+ to full city roast, which uses the manual mode, starting with P5, and dropping it to P4 or P3 at 1st crack. This method works pretty well. I try to adjust the timing of the power change depends on how beans react during 1st crack.

    To improve my roast, I’m trying to connect what I’m experiencing with Behmor to general roasting know-how.
    To gain more knowledge base to improve my roast, could you elaborate more about what is happening in Behmor specifically by each roasting stage? (In maybe your future post?)

    For example,
    – Drying stage: P5 = strongest heat + no fan = what’s happening in Behmor? What’s different from commercial roaster?
    – Pre-1st crack: P5 = strongest heat + fan (around yellowing stage) = what’s happening in Behmor? What’s different from commercial roaster?
    – Post 1st crack: P3 ore P4 = weaker heat = what’s happening in Behmor? What’s different from commercial roaster?
    – after 1st crack: cooling in the drum = Are you using this time for development?

    I’m basically trying to understand why the profile (P5 -> P3 or P4) works well in Behmor.

    I have two more specific questions.
    1) I just wonder, but does the fan speed change during the roast?
    With my 2000AB, 1/2lb mode, I start hearing the fan around 5 min mark, and the sound becomes louder 1 min later.

    2) I use 1/2lb mode for manual roasting while you use 1lb mode. Are there any differences between these two when roasted manually?
    I’m not so sure, but the timing of the fan kicks in maybe different.

    Thanks again for great resources!

    1. Hi there Yuji,

      I’m glad to hear you’re enjoying your Behmor! In comparison to stove top roasting, the Behmor has such a different feel, and probably a relief to not have to spin that Whirly Pop by hand 🙂

      “What’s going on in the roaster” is a really good question, and the knowledge that comes from understanding the different roast stages can help to inform and improve your roasting. Even on the Behmor! I say that last part because the Behmor does have its limitations. I recommend using the maximum heat settings in order to achieve a relatively short overall roast time. If you don’t, you risk a long roast, potentially ‘baking’ the coffee which leads to a flatter cup.

      The Behmor is not like most production coffee roasters, so it’s really hard to make a comparison. On our 12 kilo Probat, for example, we’re able to employ a much more varied heat profile without risking baking the roast. Gas heat and a solid steel roasting drum allow us to make more dramatic shifts in heat input, so I’m not tied to a single option to hit my marks.

      As far as “what’s going on” with the coffee during the roasting process, it’s going to be the same across all roasters for the most part. I guess how the coffee is affected by the different variables – heat, air, time, etc – is what will differ the most, which is where you, the roaster, come in.

      One of our most popular blog posts is Using Sight to Determine Roast Degree. In it, Tom uses macro images of the color changes in coffee during roasting to help illustrate the different stages in the roasting process. I think you might find it useful if you haven’t already stumbled across it!

      To your last question, I’m really not sure! I have a few tests to run on my Behmor later this week and made a note to see when the fan kicks in running 1/2 LB setting and manual mode. I assumed it was always 7:30 in, but maybe not the case. I’ll circle back after testing.

      Thanks again for your questions Yuji! I hope my answer helped, but please feel free to reply if I can further clarify anything.


  6. Hey Dan,

    Thanks for this post. I’ve recently gotten back into home roasting after a long break and upgraded my old 1600 with the newest panel, board, and motor. I’ve been roasting in manual mode and have been pretty pleased with the results I’ve gotten so far, making small changes from one batch to the next to see what I can improve. Your articles about roast development and tips for the Behmor have been invaluable.

    In regards to pre-heating, I read an article from another home roasting blog that advocated for a REALLY hot pre-heat cycle – anywhere from 250-280 on the B sensor depending on bean and preference – and using the 1 lb manual setting for the main roast (batch size ~250g-300g).

    Here’s what I thought was unusual and wanted your opinion on: The post’s author uses NO power for the first full minute of the roast. They preheat, load the drum, start manual mode, and immediately drop power to P1 until a full minute has elapsed. Their reasoning is that it is supposed to emulate a heat soak of a larger commercial roaster when the drum is charged.

    Thoughts on this? I’ve not experimented with it yet, but it seems to run contrary to everything I’ve read up to this point about starting with an aggressive heat ramp at the start of the roast.

    Thanks again for all you do!

    – Dustin

    1. Hey Dustin, welcome back! Glad to hear you’ve broken out the old Behmor and even upgraded it with the panel, board and motor. Manual mode is truly an improvement to the pre “Plus” models in my opinion.

      With regards to soaking, it’s my opinion that it greatly depends on the coffee. Soaking makes a lot of sense in a production roaster where the flame is directly below the steel roasting drum. A really high flame will mean a really hot drum, and can certainly lead to scorching. It also makes sense for roasting low density coffee, like Brazil, for example. Low density coffee can benefit from a longer drying phase, allowing the coffee more time to find equilibrium with the chamber temp, gently developing the roast so that the sugars caramelize without burning.

      I’ve not tried this approach myself, but will give it a whirl with a Brazil and compare the cup differences with my standard high heat approach.

      Thanks for the note!

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