Using a handheld fan to control heat during a popcorn roast

[stralto]

I would never bother going back to roasting in a popper without being able to control the input voltage.

I'm using a Breville Crazy Popper connected to a $35 Variable Fan Speed Controller.

No special wiring required and it provides excellent control of temperature. Of course, at lower temperatures you also get lower fan speed which results in insufficient motion and agitation of the beans. This is easily overcome by stirring for the first three minutes.

From 0C to 150C I have a small desk fan blowing over the top of the unit to reduce the ramp up temperature.

When it hits about 150C (Fan Speed controller on high-medium setting) the beans are lighter (and fan is faster) so the beans move/mix freely by themselves. From here on in I can control the temperature quite precisely (hold it within a couple of degrees), all the way up to 235C (max temp is dependent on other factors too).

I roast 100 - 120g at a time and extend the roast as long as I want

The de-coupling method jannus posted above would be an additional improvement - but i don't have the know how to do that type of wiring.

[jannus]

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?

Rating the roasts is not something I would do...as I really consider my lack of experience to be the limiting factor. I can however tell you there was a vast improvement from using it just as is without being able to control the heat, to fitting the dimming circuit. We had numerous very drinkable batches, and some that my wife even liked, or preferred to what the local roaster supplied. Could probably have been better if someone with more experience did it, but it wasn't bad. If by "woody smell" you mean burnt smell, nope, that was not a problem for us.

Just to show how really quick and dirty it can be done, here's what I did. I fitted the dimmer into an extension lead box (happened to have one handy), and plugged the popper into that. You can also see where I cut the tracks to power the fan directly.

second pic shows where I fitted the thermocouple. Arguable how good a location it is, but it works. I didn't want something in the way of the beans that I was going to knock all the time while agitating.

Cheers!

[c0alJK]

Rating the roasts is not something I would do...as I really consider my lack of experience to be the limiting factor. I can however tell you there was a vast improvement from using it just as is without being able to control the heat, to fitting the dimming circuit. We had numerous very drinkable batches, and some that my wife even liked, or preferred to what the local roaster supplied. Could probably have been better if someone with more experience did it, but it wasn't bad. If by "woody smell" you mean burnt smell, nope, that was not a problem for us.

Just to show how really quick and dirty it can be done, here's what I did. I fitted the dimmer into an extension lead box (happened to have one handy), and plugged the popper into that. You can also see where I cut the tracks to power the fan directly.

second pic shows where I fitted the thermocouple. Arguable how good a location it is, but it works. I didn't want something in the way of the beans that I was going to knock all the time while agitating.

Cheers!

Looking good, doing something very similar real soon. Thanks for sharing!