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Using a handheld fan to control heat during a popcorn roast

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  • Using a handheld fan to control heat during a popcorn roast

    Can a handheld fan, blowing cool ambient air onto the top of the beans, slow down heat and extend roast times during a popcorn roast?

    I’m waiting for delivery of my Sunbeam popcorn maker and first shipment of green beans and have been reading about popcorn mods - and really don’t want to get into electrical wiring changes- yet! Surely a handheld fan might be enough to slow down a roast a little? Perhaps applied after 1st crack?

  • #2
    Might be worth a try. When I was using a popper 10 or so years ago, I used a fan to blow air across the top rather than into the mouth of the popper. I thought this might suck the heat rather than blow it out. Did it work? Not sure. You would need to measure the roast temperature to verify. However, many popper users have successfully roasted without using a fan.

    You preferably need to reduce the heat at the onset of first crack otherwise you could find the roast going straight 2nd crack after 1st. You don't want to stall the roast though.

    Comment


    • #3
      I have done many popper roasts with a lot of different poppers. From stock standard units to the heavily modded "frankenpoppers" that I use now.
      As flynn said above, blowing the air across the top would be better than trying to force fresh air into the chamber against the hot airflow coming out.
      You also need to have the fan on right from the start, not just towards the end of the roast. In cold weather, if you can't get to the start of second crack with the fan on, the roast may be stalling and you may need to turn it off to avoid stalling the roast and 'baking" the beans.

      I've tried several variations of external fan cooling, and only two made a noticeable difference. One was a fan blowing air through large holes in the upper housing, the other was removing the top half of the case and blowing air directly onto the exposed roast chamber. The bottom half of the case still covered all of the electical connections, so it was safe.

      Here are pics of some examples
      Attached Files
      Last edited by deegee; 16 May 2020, 11:13 AM.

      Comment


      • #4
        Thanks so much for the advice and photos.
        Making holes and exposing the main cooking metal sounds like a brilliant way to control temperature.

        I'm still waiting for my popcorn maker to arrive from Good Guys - meanwhile I've been cast iron pan roasting... not sure if a popcorm maker is a better technique than cast iron pan roasting or not? Have you tried cast iron pan roasting?

        Comment


        • #5
          tcab,

          I started roasting with a cast iron skillet before moving to a popper (i'm now using a coretto set up). II got my popper to the point where I could produce a much more consistent roast than with the skillet. But every now and then now i'll roast a batch on the skillet because it's a lot of fun and sometimes its refreshing to roast a batch based on feel and not a formula!

          Personally I think it comes down to how easy you want roasting coffee at home to be. Getting your popper set up right with all sorts of mods can mean it can be pretty hands-off which might or might not appeal to you.

          Comment


          • #6
            Also from my experience I reckon it's an absolute must to move the thermostat inside the popper. If you don't, there's a high chance that the popper will cut out due to the high temp during your roast and ruin your batch.

            I think moving the thermostat in the Sunbeam one is pretty straight forward. You just have to remove the case (undo screws on the bottom) and unbolt the thermostat from the side of the popping chamber (you can see where it's attached if you look into the popping chamber - you'll see a dot on the side). Just move it to a place wheer it won't heat up too much and you shouldn't have any problems. No re-wiring needed! Good luck.

            Comment


            • #7
              wirecutter23 thanks for the advice! I will follow it and move the thermostat.
              I suspect the steps are probably very similar to those in this youtube video, which I watched some time ago.

              Comment


              • #8
                G'day tcab, No - I have never tried roasting in a pan or skillet.

                One downside of using poppers is their capacity. Stock units can usually only handle 60 to 80 grams of green beans in warm weather, and maybe 80 to 100 when it's colder. It can get a bit tedious if you need to do large quantities in such small batches.

                I mostly use a modified popper as it gives me fast response to changes, and very good control. It can handle up to 150 grams (greeen) but I usually do a bit less. I mostly do 125 gram single origin batches and blend post roast. Because I mainly roast just for myself, this is not a problem. For the occasional larger roast I have a Behmor.

                You may find that the thermostat in your popper is attached to the heater coil plate, not the chamber. If it is, don't try to move it, those mica plates are very brittle and quite fragile. The solution is to short out the thermostat by soldering a wire across it, or carefully bend the contacts together, so they cannot open, no matter how hot they are.
                Click image for larger version

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                In this pic the t'stat is the widget between B and D.
                If you haven't already seen it, take a look at this thread - it's a bit dated now, but most of the info is still valid.
                https://coffeesnobs.com.au/forum/cof...ps-tricks-mods
                Cheers, deegee.

                Comment


                • #9
                  How did you go? I recently started getting into roasting with the same Sunbeam popcorn popper and I find with this popper (this is the only one i've used) my temps are way too high, the power on this thing is too much. I wouldn't need to remove the thermostat like others do, in fact I need to turn the power down, way down. I'm getting 1st crack at about 3-5mins, roasting outside at 16c ambient (at night) with a fan on high directly at the popper + a 15m extension cord.

                  Not sure why my popper is like this but with 1st crack so soon, my roasts taste so very dry and underdeveloped I can definitely tell they're undercooked inside with a bit of uneven roast (80-100g batches, I have tried 120g but it gets even more uneven). Currently looking at ways to delay 1st crack without switching it on/off, and am now about to experiment using dimmers/potentiometers - as my last resort, didn't want to mess with electrics in the first place. Did you have the same experience?

                  Comment


                  • #10
                    Originally posted by c0alJK View Post
                    Not sure why my popper is like this but with 1st crack so soon, my roasts taste so very dry and underdeveloped I can definitely tell they're undercooked inside with a bit of uneven roast (80-100g batches, I have tried 120g but it gets even more uneven). Currently looking at ways to delay 1st crack without switching it on/off, and am now about to experiment using dimmers/potentiometers - as my last resort, didn't want to mess with electrics in the first place. Did you have the same experience?
                    Just from my side - I found it easiest to disconnect the internal fan and run that off an external 24V DC powersupply - so that always ran full speed. Then I ran the popper (essentially just the heater circuit) on a 2kw dimmer I got from a local dealer for dirt cheap. That gave quite some control of the roasting power. Add to that a temp probe, and you can get some pretty good control.

                    I found that mine worked best on 55g, and even then I'd agitate by hand until close to 1C. Anything more than that gave very uneven roasts.

                    Good luck! It's a bit messy with the chaff going everywhere, but for such small batches it's manageable with a small broom afterwards...

                    Best regards

                    Comment


                    • c0alJK
                      c0alJK commented
                      Editing a comment
                      I just bought the exact same dimmer for about $12, just waiting for it in the mail! I think that's the best way to wire it, variable fan would be nice but priority is the dimmer. What brand temp probes? And how did you hook yours up?

                  • #11
                    So far with no mods, the Sunbeam popper with 60g of beans runs OK - takes approx 15min to 20min to get a darker roast. I also bought a Breville roaster from JB which is more powerful, and I have to reduce times by about 3 mins for it. I run both popcorn roasters at the same time and get 120g batches, often mixing the results of the two machines into resealable plastic bags and labelling them with my Brother 12mm tape labeller. The temps using my laser measuring device seem around 180C +- 20C which I don't think is too hot and seem to be the minimum temperature for proper roasting - much hotter and better than my cast iron roasting attempts which were 160C or so and I was probably getting underdeveloped baked coffee instead of roasts.

                    With these popcorn makers, I was initially getting underdeveloped, woody expresso blends but have found that by resting the beans at least a week and blending with just two beans I am getting much better results. For example a 60% El Salvador + 40% Brazil tasted surprisingly complex and good - giving me hope.

                    I was previously blending 4 beans trying to get the right recipe. Then I tried a coffee at a Williamstown coffee shop and was astounded at how good the coffee was so bought 250g of their beans, only to find out it was a simple 50% Brazil 50% Columbian. That inspired me to simplify my blends. Yesterday I had an expresso from a local cafe which was 100% Brazil and it had plenty of complexity.

                    I have been thinking about getting a Behmor coffee roaster now that they are in stock but read a few blogs and posts about the need for hacks and custom roast profiles etc, tin foil tricks etc. which has put me off.

                    Comment


                    • #12
                      Originally posted by tcab View Post
                      So far with no mods, the Sunbeam popper with 60g of beans runs OK - takes approx 15min to 20min to get a darker roast. I also bought a Breville roaster from JB which is more powerful, and I have to reduce times by about 3 mins for it. I run both popcorn roasters at the same time and get 120g batches, often mixing the results of the two machines into resealable plastic bags and labelling them with my Brother 12mm tape labeller. The temps using my laser measuring device seem around 180C +- 20C which I don't think is too hot and seem to be the minimum temperature for proper roasting - much hotter and better than my cast iron roasting attempts which were 160C or so and I was probably getting underdeveloped baked coffee instead of roasts.

                      With these popcorn makers, I was initially getting underdeveloped, woody expresso blends but have found that by resting the beans at least a week and blending with just two beans I am getting much better results. For example a 60% El Salvador + 40% Brazil tasted surprisingly complex and good -giving me hope.

                      I was previously blending 4 beans trying to get the right recipe. Then I tried a coffee at a Williamstown coffee shop and was astounded at how good the coffee was so bought 250g of their beans, only to find out it was a simple 50% Brazil 50% Columbian. That inspired me to simplify my blends. Yesterday I had an expresso from a local cafe which was 100% Brazil and it had plenty of complexity.

                      I have been thinking about getting a Behmor coffee roaster now that they are in stock but read a few blogs and posts about the need for hacks and custom roast profiles etc, tin foil tricks etc. which has put me off.
                      It seems 60g is the sweet spot, will have to try that next. Glad yours can get you 15 mins roast, I struggle to reach that time before burning it - it's happened once haha. And yes, I hate that woody smell so much, but you are right i'm noticing it fades away slightly after >5 days. I have a good feeling it's cause of the rapid heat of the popper. I'm really hoping I can get some level of complexity when I get to adjust the heat, but stock as is now tastes unbearably bad... really flat and acidic.

                      Agreed about the blends too, I haven't done home blends but the best shop ones I've tried only had maximum of 3 beans. Also I'm in the same position as you, came very close to just buying a behmor to skip all this frustration but deciding on a better roaster in the long term so i'm saving up. Really banking on the mod to get me some decent roasts at least to get by now :/

                      Comment


                      • #13
                        Originally posted by c0alJK View Post

                        I just bought the exact same dimmer for about $12, just waiting for it in the mail! I think that's the best way to wire it, variable fan would be nice but priority is the dimmer. What brand temp probes? And how did you hook yours up? :/
                        I used a K-type thermocouple I ended up getting from a local hobby shop, was dirt cheap. Probably not ideal, but it works well.
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                        I hooked that up to an arduino, and ended up adding a solid state relay as well, so the fan ran full speed (if it ran slower the beans probably wouldn't move anycase), and the SSR / temp probe combo controlled the rate from Artisan with Artisan doing the PID. It was pretty responsive. There's so much air moving around, I used it only as a drum temp kind of sensor, never tried to get meaningful BT readings.

                        Cheers!

                        Comment


                        • #14
                          Originally posted by c0alJK View Post

                          It seems 60g is the sweet spot, will have to try that next. Glad yours can get you 15 mins roast, I struggle to reach that time before burning it - it's happened once haha. And yes, I hate that woody smell so much, but you are right i'm noticing it fades away slightly after >5 days. I have a good feeling it's cause of the rapid heat of the popper. I'm really hoping I can get some level of complexity when I get to adjust the heat, but stock as is now tastes unbearably bad... really flat and acidic.

                          Agreed about the blends too, I haven't done home blends but the best shop ones I've tried only had maximum of 3 beans. Also I'm in the same position as you, came very close to just buying a behmor to skip all this frustration but deciding on a better roaster in the long term so i'm saving up. Really banking on the mod to get me some decent roasts at least to get by now :/
                          Running a popcorn maker as is I found to be way too hot and way too quick. It would get to 1C then 2C really really quick, almost uncontrollable. Using the dimmer and the fan wired as I did, you can turn down the heat as much as you want, and find a good rate. Even if you're flying relatively blind, there's a lot more control, and you can get some decent roasts from it. Of course at the end you can do a very nice cool down phase right there by just turning the heat back and letting the fan carry on. The biggest disadvantage is the small volume you have to work with.

                          Comment


                          • #15
                            Originally posted by jannus View Post

                            Running a popcorn maker as is I found to be way too hot and way too quick. It would get to 1C then 2C really really quick, almost uncontrollable. Using the dimmer and the fan wired as I did, you can turn down the heat as much as you want, and find a good rate. Even if you're flying relatively blind, there's a lot more control, and you can get some decent roasts from it. Of course at the end you can do a very nice cool down phase right there by just turning the heat back and letting the fan carry on. The biggest disadvantage is the small volume you have to work with.
                            Cheers for the info, do you find that you could produce some excellent quality roast? How would you rate it /10?

                            How about the woody smell, do you notice any of that still?

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