Coffee Cup
"Espresso! My Espresso!"
An Ongoing Internet Novelette
by Randy Glass - Copyright 2021 - All rights reserved

Coffee Cup
Santoker Revolution 500
My First Roast in 29 Months!
Wednesday, April 14, 2021

all text and photos ©2021 - All rights reserved

    The wave of excitement came and I was overwhelmed. As explained in a previous chapter I ran my first roast in 29 months! My Santoker Revolution 500 was nearly ready when my Phidigets arrived with the necessary cables, and the next day my used laptop arrived, and I had already received my forty pound order of green coffee.

    Phidgets couldn't be easier to install. Thermocouples under the screw clamps, connect the cable between the thermocouple unit and the hub, and a USB cable from the hub to the computer. Install the Phidgit library and then Artisan. That's about it! The rest of the setup is done in Artisan to select the Phidigets as the input to be monitored.

    I had every motivation to roast coffee including a deep desire to never drink Peets coffee again. Not that it was terrible, but the two versions available locally which were not burnt offerings were lacking in soul. I will be kind and say that they resembled coffee sufficiently to be drinkable.

roast setup
My Santoker Revolution 500, setup and ready for my 1st roast

    I knew the last required delivery was imminent so I had downloaded the software I needed onto a thumb drive. My wireless hotspot connection is undependable on a good day so I wanted to be ready. The laptop arrived and as soon as it was doneinstalling the initial Windows setup nonsense I was installing Firefox, the Phidget library, and Artisan Roaster-Scope. The only other obstacle was the viewing window on the face of the roaster.

    The view port glass was badly cracked when I got it and before I roasted coffee I wanted to replace it. I was unsure of the size and thickness. I measured it as 30mm in diameter, but the thickness was difficult to quantify. I thought it looked quite thin by placing a finger on the glass from the front and another on the back. But I devised a way to use my digital calipers while the glass was in place. To overcome the back side of the lens being recessed deep into the drop door I placed a nut up against the glass to, in essence, make it thicker. After measuring the distance and subtracting the width of the nut I was able to get a measurement that turned out to be about 2.48mm thick.

    While I was measuring with my dial caliper the glass fell out in three large pieces and a number of tiny ones. I had the diameter correct at 30mm by measuring the now-vacant opening in the door, and I measured the thickness of a larger shard I found that it was, indeed, 2.5 millimeters thick. Now, the question was: how to find a replacement?

    I checked Google, Graingers, and sent a text to a Chinese company selling a similar roaster but all that yielded nothing useful. Obviously you cannot subject a piece of common glass in an appliance that can easily exceed 400 degrees. Folks on helped steer me to an unlikely source (or at least one I would not have thought of); sapphire watch crystals. They are able to withstand far greater temperatures than roasting coffee I was told. Off to eBay and I found a seller in Texas who had that size crystal at a good price. In the meantime I cut a thin piece of sheet metal to around 33mm in diameter and that was able to cover the hole. “A roasting we will go!”

    One piece of information I could have used was the best drum speed to dial in. The drum motor on these imported roasters is controlled by a variable speed unit and adjusted by a knob on the back of the roaster. As it is used on a large number of appliances it has no calibrations marked.

speed control

    Additionally, the 220vac motors run on 50 or 60 Hz. Using the lowest speed barely turns the drum and the highest speed is impossible to estimate; the drum becomes a blur to the naked eye. A coffee roaster drum speed chart I had saved from years ago states that my 6in. diameter drum should have a minimum speed of 6.5rpm (one revolution every 10 seconds), a maximum speed of 95rpm (1.5rps), and a “sticking speed” of 108rpm (1.8rps) where centrifugal force eliminates the tumbling of the beans. Slow is quieter and faster is a more even roast. Rounding off with disregard, with a range of about 7 to 100 RPM, I just guessed by observation that around 60rpm (1 revolution per second) before I added the beans. It looked right. I must have chosen a good speed because the trier was easily filled each time during the roast. The next day I made a mark on one of the stirring vanes in the drum and counted the mark's passing , timing it for fifteen seconds. When I found that the drum speed was 60rpm I made a mark on the speed control to allow repeating the speed easy.

    I won't go into the minutiae of the roast because, frankly, the first roast I had ever done on any gas roaster was a mental whirlwind. I began roasting twenty years ago on air roasters, and eighteen years ago I switched to the Hottop roaster when I received the first to be imported into the United States.

    Dustin Demer was the original importer of the Santoker as I understand it, and in his YouTube videos on the use of the roaster he cautions to pay very close attention to the roast once the drying phase ends and the development phase begins. He was right, and it is good advice concerning any roasting method. I should have turned down the gas right as first began and a bit more as it ended to slow things down. I was pulling the trier over and over and it was amazing how quickly things went. Drying ends and then light tan, tan, light brown, first crack, medium brown.. Boom, boom boom, just that quick. I dropped the roast before second and it looked like this:


    The massive cooling fan cooled the beans in about one minute even without a stirring arm. All I did was to shake the cooling tray around a bit to get the beans leveled. As you can see, the roast was very even and that is a sign that the drum speed was optimal. Almost immediately the aroma was absolutely enticing! I ate a few beans and the taste was enough to tell me that this was going to be a tasty cup.

    Later that day I took a pre-weighed bowl of the beans portion for the Behmor Brazen into the RV and ground them on the Kafetek MC3. Maybe not the first choice for grinding for drip, but it will do when it is all that you have. We took the grounds into the house and I brewed a pot. It was well balanced with a flavorful finish which I would describe as nutty and rich.

val and cups
Val enjoying a delicious cup of coffee

    I have to add that in my two decades of coffee enthusiasm and eightreen total years of coffee roasting, this batch of coffee was, by a good stretch, the best roast I have ever done. That's a fairly bold statement, but I have never had beans emerge from the roaster with such a rich aroma, and then later back up its olfactory claim with a taste to match.

    It was very difficult keeping an eye on Artisan, pulling the trier, and trying to keep up with the pertinent points I turned into instructions which I stenografied from Dustin's videos.

    I question the location of the thermocouples. The bean thermocouple seemed to be pretty good, but the ET data seemed odd and did not seem to reflect what I was doing. There is work to be done there.

    My wife came in right at the time I was hitting 1st and started commenting and questioning. A distraction at a time that was inconvenient as well as the fact that my mind was swimming through a turbid lake of whats, whens and hows. It should be enough that I usually remember to zip up let alone try to be a roaster and a husband at the same time!

    I have a great future with this roaster. Slowing down the development phase and ending the roast sooner will bring out even more from these beans. But it was my first 'drive' in this new car and I need to learn the shift points and that will take time. But no hurry. I have only been doing this for two decades, so there is still a lot to learn.

    I will leave you with this. In one of the Mill City Roaster School videos there was a statement that said something in the order of, “If the boss asks me, 'What did I learn today when roasting?' and I can't give the boss an answer, I should be fired.”

    So many beans.. So little time.

Coffee Cup
  -   -   - Silvia
  -   -   -
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