I have been roasting with the FreshRoast SR 500 for several months and have seen wildly differing advice from a variety of sources. Recently I found information from a few sources that when combined have resulted in some really nice roasts.
The first piece of information I found was the temperatures for the heat settings of the FreshRoast SR 500:
| Setting | Temp |
| :-------- | :----- |
| High | 490 |
| Medium | 455 |
| Low | 390 |
The second piece of information I found was the temperature at which coffee beans begin a process called pyrolysis. At about 400 degrees Fahrenheit pyrolysis begins in coffee beans. Pyrolysis is the process of chemical change within the bean that generates heat. When this process happens in coffee we hear it as a popping sound known as first crack.
In the SR 500 a temperature setting of Medium is high enough to raise coffee beans to this temperature. I had been using a high heat setting to roast coffee, and the resulting beans had a very smoky flavor, which was not very pleasant.
Additional research yielded some additional wisdom that I find sound.
1. Apply adequate energy at the beginning of a roast
2. Make sure that the bean temperature progression always decelerates
3. Make sure that first crack begins at 75% to 80% of total roast time
This information is sound when trying to roast to a City or City+ level, which is fortunate for me as I am aiming for a nice medium roast for pour over coffee.
According to an information card I received from Sweet Maria's with my first order of coffee from them, city/city+ is achieved at the tail end of first crack at a temperature range of 415 to 435 degrees.
Applying adequate energy at the beginning of a roast is not the problem with the FreshRoast SR 500. I find that the roaster applies too much energy and roasts much too fast. If anything, I needed to find a way to slow down the drying phase, as the beginning of the roast is often called, and developed a procedure for stretching that out with this roaster.
I start by using an interval timer app on my tablet designed for use with interval training exercise to precisely time the steps in my process. To slow down the initial drying process I alternate heating for twelve seconds and cooling for six seconds and repeat this cycle for twenty-four intervals. The interval timer helps me remember what step I'm on and prompts me to switch the roaster from heating to cooling and back precisely. During this phase I apply only low heat with the fan speed on high. I also physically lift the roaster base and tilt the roaster several degrees away from vertical and rotate the roaster around its vertical axis. This agitates the green beans in the chamber and helps prevent scorching. I roast batches of 90 grams and find that this batch size also prevents scorched beans.
A decelerating temperature progression means that the rate of temperature rise should slow down during the roast. It doesn't mean that the temperature should lower but that the rate of temperature increase should be faster earlier in the roast and slower later in the roast. When the beans reach first crack there is a spike in bean temperature from the heat being generated internally by pyrolysis. In anticipation of first crack and knowing that the roaster will not respond instantly to changes in heat settings, I lower the heat just prior to first crack.
The advice to make sure that first crack begins between 75% and 80% of total roast time is only a guideline, but I find that adhering to it gives me very nice coffee. So with all of this information up front, here is how I apply it with the FreshRoast SR 500.
I begin by preheating the roaster using high heat and the fan control at the 3 O'clock position. This allows all of the roaster parts to absorb as much heat as they can and prevents the roaster from sucking heat away from the beans. I follow a set rhythm while roasting one 90-gram batch at a time. While the beans are being cooled by the roaster after completing the roasting cycle I weigh out the next 90-gram batch. When the roaster stops I immediately pour out the beans into a tray, turn the roaster back on using low heat and low fan speed, clean out the chaff collector, and load the next batch of beans into the roast chamber.
Preheat the roaster for 2 full cycles at a fan speed of 3 O'clock and using high heat. Run the roaster on low heat and low fan speed between batches.
Start with a roast time of 2.8 minutes. Roast 90 grams per batch.
| Description | Heat | Fan Speed |
| :------------------- | :------: | :---------: |
| \*Drying Cycle | Low | High |
| @ 1.9 | Medium | 1 O'clock |
| @ 1.1 (FC) \*note | Low | " |
| @ 0.5 | " | 3 O'clock |
| B4 End of FC | Cool | High |
Drying Cycle: Alternate heating for 12 seconds and cooling for 6 seconds. Tilt the roaster several degrees from its vertical axis and rotate it around that axis during this process. Repeat this for twenty-four iterations. Continue rotating the roaster until the first sign of first crack.
note: Stop rotating the roaster at the first sign of first crack.
I'm sure there is plenty of room for improvement in my procedure. Adding a thermocouple and noting the temperature during the roast would be very helpful in knowing what is happening while roasting. Sweet Maria's sells one along with a battery and a temperature probe as a package that is cheaper than what Amazon will charge you for the same components. It's about $30 from them.
I hope this helps either you or anyone else that might be looking for information for the FreshRoast SR 500.
