Can be a useful device for roasting a variety of coffee. Also has limitations.
Positive Product Points
It really does produce no smoke. You can easily use it indoors without any ventilation.
If you want to use it as designed it is incredibly easy. Just input the time and hit start.
Seems like a very well built machine for the price.
Some roasts produced by this machine are superbly excellent.
Very even roasts.
Negative Product Points
A little noisy. Can't really hear the cracks (especially second).
Chaff collection doesn't work too well.
A lot of parts to clean.
Some roasts produced by this machine taste flat.
When I first got the machine I used it according to its instructions. Which is dump the beans in up to the line. Input the amount of time you want for the roast and hit start. It's incredibly easy.
The machine defaults to a 20 minute roast (which is 15 minutes of roasting with a 5 minute cool down). You can increase the total time to 30 minutes before you hit start. Once you hit start and the time starts to countdown you can add minutes one at a time, up to 5. This gives the machine a maximum time of 35 minutes (30 minutes of roasting with 5 minutes of cool down).
I did my first roast at 27 minutes. According to the instructions this would put me in the dark roast range. However, the resulting roast was just barely approaching a full city roast. The resulting taste was very flat compared to what I'm used to in my Poppery II. But the roast was attractively even.
I've since learned to preheat the machine for about 4-5 minutes, take off the top (the machine stops), dump in the beans, put the top back on (the machine starts again), and then roast for about 10-14 minutes. Doing this has greatly improved the taste. In fact, some roasts have turned out quite excellent. Now when I buy a new variety, I'll always test it out in both the PII and the Z&D. I'm finding that it's generally about 50-50. Half I like better in the Z&D and half I like better in the PII.
I'm finding that if it's a bright, spicy, wilder coffee such as an Ethiopian Harrar, the Z&D doesn't seem to bring out all the flavors that I can get on a PII. Although it does do a more even roast.
In contrast, I've found that some richer, more full-bodied coffees such as Costa Rican Tarrazu La Minita are way better in the Z&D than the PII. Much more body and aroma.
I've also begun skipping the machine's built-in cooling cycle. Before, after the 5 minute cool cycle was complete, the beans (and the machine) seemed way too hot. Now I let the machine cool for about 30 seconds or so and then dump the beans into a collander over a fan and stir for about a minute and then the beans are at room temperature. I think this is helping the flavor.
The chaff collection cup doesn't work all that well. There is a lot of chaff left in the beans, but that blows out with my cooling method.
Since you can't hear the cracks, you have to judge the roast by its color and through experience with each variety. The machine is remarkably consistent. Using the same lot of beans at the same length of roast will always provide the same result. This is hard to do in a Poppery.
All in all, I think the machine is pretty good for not much money. It's found its place as ONE of the tools I use to roast coffee.
Bought from Coffee and Kitchen, straight foward and no problems.