Latest Posts

  1. A Look at  Flores Manu Lalu as Espresso

    A Look at Flores Manu Lalu as Espresso

    Wet process Flores makes fantastic single origin espresso. Have a look at our cupping notes.

    Read More
  2. A Guide to Air Roasters

    A Guide to Air Roasters

    When blowing hot air gives you solid results

    Read More
  3. Behmor Espresso Roast Profile: Peru FTO Don Rigoberto

    Behmor Espresso Roast Profile: Peru FTO Don Rigoberto

    Read More
  4. How to Roast Coffee (circa 1850) !

    How to Roast Coffee (circa 1850) !

    When roasting at home was the primary method, and buying from a shop was your plan b !

    Read More
  5. The Golden Bean Bronze Medal Bullet Profile

    The Golden Bean Bronze Medal Bullet Profile

    Check out Julio's award winning profile.

    Read More
  6. Behmor Roast Profile: Burundi Kayanza Gahahe

    Behmor Roast Profile: Burundi Kayanza Gahahe

    Taking the "light and bright" approach to roasting Burundi Gahahe on the Behmor 1600+

    Read More
  7. Roasting Different Batch Sizes of Burundi on the Behmor 1600+

    Roasting Different Batch Sizes of Burundi on the Behmor 1600+

    What happens when you roast a coffee to the same roast level but at different rates of development?

    Read More
  8. Behmor Roast Profile: Burundi Kayanza Dusangirijambo Coop

    Behmor Roast Profile: Burundi Kayanza Dusangirijambo Coop

    Read More
  9. Live Stream: Intro to Home Roasting

    Live Stream: Intro to Home Roasting

    Roasting with an electric popcorn popper is easy! Watch our online, interactive demo on 9/6 and we'll show you how.

    Read More
  10. Roasting Flores Gunung Gedha on a Popcorn Popper and Quest M3s

    Roasting Flores Gunung Gedha on a Popcorn Popper and Quest M3s

    Read More
  11. Coffee Roasting Demo at The Berkeley Public Library

    Coffee Roasting Demo at The Berkeley Public Library

    Read More
  12. Coffee Roasting Basics: Nerd Nite Silicon Valley 6/25

    Coffee Roasting Basics: Nerd Nite Silicon Valley 6/25

    Read More

Air Popper Modifications -Adding a Thermometer

Air Popper Modifications -Adding a Thermometer

If you choose to alter your air popper you are assume the risk that it will no longer work as it was designed to, that it might not work at all, that you might injure yourself in performing these tasks or in using the altered device. This information is here for you to peruse, but Sweet Maria's accepts NO responsibility in what the results may be.

Adding a Dial Face Thermometer

A thermometer can help you establish a more consistent roasting routine. Adding a thermometer to your air popper measures the temperature of the forced air heat flow after it has passed through the beans. Therefore, it is neither an empirically accurate measurement of the bean temperature, nor of the roasting chamber. That means that a guy roasting in Chicago with a UEI brand thermometer in his Popcorn Pumper and someone from Tulsa with a Pelouze thermometer in a Poppery II cannot accurately compare their roasting notes. It does mean that the first guy can observe that his Sumatra reached a higher final temperature in 5 minutes than his Harar, or that 2 ounces roasts hotter than 3 ounces, etc.

We sell a Update pocket type thermometer which is a good value. It has a 5" shaft which makes it ideal for the Whirley-Pop and adequate for the air poppers. As the beans lose their moisture and begin to rise, they meet the 5" shaft and your readings will be accurate. It's always in the airstream, anyway. The 400 degree candy/deep fry thermometers are widely available too but I don't like extrapollating the measurements between 400-500 degrees, since that's where temperature is critical. 500 degree thermometers with longer shafts are available, and would be ideal for the air popper but they are prohibitively expensive.

A. Thermometer mounted in butter cup dish (old air popper) B. Thermometer clip holds it in place
C. Shaft extends into chamber 1 inch to 2 inches from bottom
The easy way to add a thermometer is to consult Ken Davids book, Home Coffee Roasting, and follow his instructions: basically, you drill a hole in the plastic popper hood at the exact center of the circular roast chamber and drop your thermometer into it. Simple, eh?

We found that this installation method, with or without the thermometer clip, made the thermometer wobble around a lot in the air stream and as the beans came into contact with the shaft. One possible variation is to simply fix the thermometer to the hood with the RTV type sealant mentioned below. But we like to remove the thermometer to use in our other roasters, or for cleaning.

So we searched far and wide for some sort of metal fitting, ideally a sort of collared bearing with a locknut to keep the thermometer in place, but allow for its removal. We couldn't find anything that would fit the bill. So we compropmised by modifying a common fastener called a Tee Nut, and adhering it with high temperature RTV sealant.

 

What you need:

  1. 8/32, 9/32 or 10/32 Tee Nut -local hardware store
  2. High Temp RTV Sealant -auto parts store
  3. Drill and bits: possibly 5/32, 7/32, 15/64, 1/4, details below.
  4. Wire snips or sheet metal snips

What to do:

  1. First of all, Tee Nuts have little barbs that need to be clipped off with the snips.
  2. Try to size the Tee Nut to the diameter of the thermometer shaft you will be using. If it is not a really tight fit, don't worry.
  3. Open the RTV sealant and, with and coat the inside (threads) of the Tee Nut . This will help the thermometer grip and fit snug. I use a small nail to coat the threads. The idea here is to be able to remove the thermometer, so don't block the hole with the sealant.
  4. Drill a hole in the popper hood with a diameter a tad larger than the outside diameter of the Tee Nut shaft.
  5. Put 3 dabs of RTV sealant under the colar of the Tee Nut and fix it in place on the hood. Let it all dry before forcing the thermometer into place for the first time.