I bought the I-Roast in August 2004, about four and a half months ago, and have roasted about 75 batches of beans in that roaster. I bought a second I-Roast about one week ago. The bottom line is that I love the roaster. If you have not roasted your own beans, you should try it. The I-Roast is very easy to use. The improvement to your coffee from roasting your own beans can be remarkable.
The I-Roast is a hot air roaster. The air moves upward from the base of the unit to roast and mix the beans in a glass bowl, which screws onto the base. The chaff is blown into a cylindrical metal screen inserted into the chaff collector that screws onto the glass bowl. The chaff collector has a metal lid with a screen. The roaster thus consists of four parts: the base, which houses the motor; a glass bowl, which houses the beans and screws onto the base; the chaff collector, which houses the cylindrical metal screen and screws onto the glass bowl; and a lid, which screws onto the chaff collector.
The fan in the I-Roast I bought in August 2004 alternates between two speeds during the roast, low and high. At first I wondered if something was wrong, but that is how it works. The fan in the I-Roast I bought in December 2004 does not alternate between two speeds during the roast. It operates at the higher roasting speed of the earlier model. The new model circulates the beans better, both during the roasting phase and the cool down phase. The better circulation of the beans results in a more uniform roast. Apparently, the unit was still being perfected when originally released.
In the unit I bought in August 2004, I find that using about 7 oz or less (liquid measure) of green beans per roast produces the best results. In the unit I bought in December 2004, I find that the unit works fine with 8 oz (liquid measure) of green beans per roast. The manual states that two full ½ cups of beans equates to approximately 5.3 oz . Using too many beans prevents the air from mixing the beans properly, and results in a less uniform roast.
The coffee is roasted at different temperature settings between 325°F and 485°F for three periods, or cycles, that can last up to 15 minutes total. The combination of the three temperature settings, and the duration of the roast at each temperature, is called a roasting profile. The real advantage of the I-Roast is the ability to create custom roasting profiles by specifying the temperature and duration of each of the three cycles.
After the third cycle, there is a 4-minute cool down period. The 4-minute cool down period applies regardless of the roasting profile that is selected.
There are two preset roasting profiles, as follows:
Preset 1: 485°F for 6:30 min; 440°F for 3:00 min.; 485°F for 1:30 min.
Preset 2 485°F for 5:00 min; 440°F for 5:00 min; 485°F for 1:30 min.
I find that these roasting profiles result in a roast that is too dark for my taste. After experimenting, I have settled on the following roasting profile, if the temperature of the location where the roaster is used is around 75° (if the roaster is used outside in colder temperatures the profile needs to be adjusted; it takes longer for the roaster to reach the designated temperature when the ambient temperature is colder):
350°F for 3:15 min; 400°F for 5:30 min.; 445°F for 3:10 min.
I like the above profile for regular coffee using Kenya beans (I typically do not drink espresso). Your preferred profile, of course, may differ. Individual units may run hotter or cooler, which can affect the optimal profile setting. The type of beans used can also affect the desired profile. The ability to set a custom profile is a huge advantage of the I-Roast.
The final minute of the roasting cycle, when the beans are the hottest, is the most critical. The taste of the coffee can change dramatically by roasting the beans even 15 seconds more or less in the third cycle. You will need to experiment to find the roasting profiles you like the best. You can watch the beans through the clear glass bowl as the roaster operates, and manually increase or decrease the time for the third cycle during the latter part of that cycle. This is a good feature, as eyeballing the beans during the final portion of the roast can help to get the roast you want, given the variables of the ambient temperate and type of beans used.
The roaster is well designed. When the roast is finished, the glass bowl that houses the beans and the chaff collector can be removed separately. The beans can then be removed from the glass bowl. After removing the lid from the chaff collector, the chaff collector can be turned upside down, and the cylindrical metal screen removed. Most of the chaff will have collected in the cylindrical metal screen. With a little practice, it is easy to remove the chaff without spilling it.
There is a prominent warning label on the roaster that says “Do not roast more than 7 times a week! … Do not exceed more than 2 batches at a time. You must allow 30 minutes shut off time before starting the second roast....” I find the instruction “ Do not exceed more than 2 batches at a time” to be unclear. Perhaps that means that if two roasts are performed 30 minutes apart, more than thirty minutes should elapse before the third roast. I roast enough beans over the weekend for the following week (which is about 6 batches).
There is a connector for an exhaust tube. I have not used it as I prefer to roast outside, notwithstanding the admonition in the manual not to use the roaster outdoors.
The roaster is easy to clean. After each use, I brush the chaff, with a brush included with the unit, from the chaff collector ring, the chaff collector, and the lid. About twice a month, I clean the unit with soap and water (other than the base, which houses the motor).
A few characteristics or oddities of the roaster merit special note. First, the designated temperature will be hotter than the temperature displayed when checked during the roasting process. This is no big deal. The manual states that the temperature displayed when checked is the upstream hot air temperature not the inside bean temperature. Second, if the roaster gets cold, it will not start. Accordingly, if you use the roaster in a cold garage or outside in cold temperatures, you will need to store the roaster indoors, or let it reach room temperature before roasting. Third, the roaster is somewhat noisy. Is it, after all, a hot air roaster. Finally, if the roast is interrupted, the roaster will go into the cool down mode. If this happens, at least on the model I purchased in August 2004, it may be necessary to reset the roaster to get it started again by pushing the preset #1 and the roast buttons alternatively in rapid succession until the roaster starts, and then by pressing the cool down button and letting the roaster run through that cycle. This can be a pain. I have not been unfortunate enough to test the reset on the model I purchased more recently.
Can the I-Roast be improved? Sure. It already has been improved from the version of the model originally released. The single biggest further improvement in my view would be to increase the roasting capacity. But the bottom line is that I think is a great machine for the price.