Home Coffee Roasting with a Hottop Coffee Roaster, part 2

The Hottop's Roasting Capacity

The Hottop can roast up to 300 grams of beans at one time, but the recommended load is 250 grams.  I found that I could roast most beans for at 270 grams (haven't tried 300, yet), but I couldn't get Sweet Maria's Espresso Monkey blend dark enough at 270 grams, even with the maximum of five "Plus" button presses.  Dropping back to 250 gram batches of Monkey solved that problem easily enough.  The manual advises that adding 20 grams is the equivalent of reducing the roast profile by one setting (i.e., set it at "7" for an effective "6" roast). -- Later note:  Hottop revised the profiles so that a "+" adds 20 seconds instead of the original 10 seconds.  With the new EPROM chip from the distributor, my Hottop now can roast as dark as I want.

Why did I wait so long to get the Hottop?  Once it was finally available in the U.S., I still took my time.  I kept noticing the "it's quiet" comments and the batch size comments, and somehow missed the "better coffee" comments.  I like this roaster!

Voltage Control - the Variac

I added a variac from Circuit Specialists to my setup to make my roasts more repeatable.  The Hottop didn't have a problem -- it was summer in Baton Rouge.  I found that roasting early on a Saturday morning gave me 118 volts of electricity.  Roasting later in the day or during late afternoon, I would have only 115 or 116 volts.  Since V=IR (volts = current times resistance), lower voltage meant lower current across the heater, which meant less heat applied in the Hottop.

The solution was a variac, a variable transformer.   This simple tool plugs in to your wall socket or heavy-duty extension cord.  Mine is a hefty 20 pounds or so of copper and iron, with a big knob in the center.  Instead of having a fixed ratio of incoming voltage to outgoing voltage, the knob moves a connector in the transformer so there are more or fewer coils being used.  In other words, you turn the knob to reduce or increase the voltage.  I use a digital voltmeter, also from Circuit Specialists, to monitor the voltage through the roasting process and adjust as necessary.

Temperature Monitoring - The Digital Thermometer

I also added a digital thermometer from Circuit Specialists.  I insert the thermocouple into the beans as they are tumbling in order to monitor the temperature.  The thermocouple goes through the bean chute of the Hottop and down into the mass of beans.  Sweet Maria's now carries this same digital thermometer.

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Copyright © 2003-2006 Terry A. Stockdale