repatter wrote:I would like to have a serious discussion about profiling roasts on the Huky 500.

I want to preface by saying that the type of coffee I strive to roast is coffee that is beautiful with clarity and origin characteristics and shines when brewed with a highly precise pour over technique. So my roasts are lighter, but not so light that there are herbaceous qualities and unripe acidities, but not too dark that the inherent complexity of the coffee is masked by the generic darker tones of a more developed coffee.

My opinion about the Huky: The Huky is a stylish machine that has certain things it does well (accuracy and repeatability) but there are many flaws if one is looking to roast precise and clean coffee. My set up is the solid drum with 72 rpm motor. I had the perforated drum but I felt that it added another variable to the roasting process and it did not give the finesse I was looking for. I use the IR burner that comes with the roaster, which is not very responsive and can cause problems if too much flame is applied.

This has been the opposite of my experience but I've only used a Behmor and Hottop- both electric heating elements. What heat sources that that are more responsive?

The fan is super strong, so I got a light dimmer to increase the resistance to the fan and have lower fan speeds. Even on a low fan speed most of the chaff comes off easily. Over many failures of experimenting with the fan, I have learned to simply have the fan on the same low speed throughout the entire roast, so to create a repeatable and simple method for controlling airflow. I use Artisan profiling software, which works well for what I need it to do. However, there are limitations to this machine, some of which I will explain my experience and I would hope others also participate.

People, including the builder, claim that the Huky can roast 1 lb no problem. In my experience, the roasts are too long if one roasts that large of a quantity, or the flavors get burnt away by too strong of flame. When roasting with the Huky, the machine is not sensitive to many heat changes, particularly if you load up the roaster with 1 lb. An intuition must be learned to know when to apply and remove heat.

I decided early on to roast one pound at a time, have done about 150 one pound roasts. Never even tried smaller loads, but I can say without reservation that the Huky can roast one pound at any speed I desire, and that burnt flavors haven't been an issue since I got the hang of the controls. I even tried this super fast technique that people have been talking about lately- first crack in six minutes with a charge temp of 465F. Results with the 3 roasts (Ethiopia, Rwanda and Guatemala) I tried that way had no discernable "roast" flavors.

In order to get a good drying time (green --> yellow) the preheat charge temp must be pretty high, even with a low fan speed. Without any fan, you would need a much higher charge temp to reach the same turning point. This is the one of the problems of this machine with large loads; tipping is rampant, especially with softer Central American and Indonesian coffees. And in my experience too hot of temps tend to ruin aromatics and the complexities spoil soon after roasting rather than improving after as the coffee rests. However, when I try to have lower charges and therefore lower turning points, the drying phase is much too long and a dramatic bitterness spoils the cup.

Tipping hasn't been an issue for me- I'm surprised you're seeing it since I also run the fan at a low-ish speed throughout the roast. What are your charge temps? I'd love to see one of your unhappy profiles with all the fan and heat changes along the way- maybe we can nail down what is causing these problems for you.

This brings me to my second complaint, which is the lack of sensitivity of the roaster. Even if I apply a boatload of heat in the beginning, the temperature rise is still not going to catch up in time to have a decent drying time, and further the excess flame will over develop the beans. That is where that balance of flame application and roast development is crucial, because it is easy to apply a lot more heat so the roast times are more ideal, but the extra flame has invisibly scorched the beans, leading to a flat, dismal cup.

What are you aiming for as a decent drying time? Using my standard 30% fan setting I can hit 300F at pretty much any time I want by varying the charge temp and stove setting. With the crazy fast profile 300F came in at about 3:15 and with a more traditional profile it's 4:00-5:00 depending on what I'm aiming for.

So then, the compromise of flame application and duration of roast is to lengthen the roast by having just hot enough charge temp to get a good drying time, but not apply too much heat so the middle phase (yellow --> first crack) is extended. This tends to create way too many melanoidins, aka those browning components that add to body and flavor, showing an over developed coffee with too thick of a body.

Also to comment on the manufacturer's idea of no fan in the drying phase, full fan and flame from yellow to before first crack and then little fan throughout first crack, I have not had success with this method. With larger batch sizes, the preheat temp with no fan is through the roof (535F!) to get a 212F turning point, and then the rate of rise is very slow. As read in Scott Rao's "Coffee Roaster's Companion," if the temperature gradient of outside bean development and inside bean development is small, a under ripe sourness results in the final cup, which is what I found when doing the manufacturer's technique. It was only when I used the fan throughout that I got drying times that were more suitable with my preferences.

In sum, I have not found a good way to roast large batches, which is frustrating because I bought the machine with the assumption that it could handle 1 lb batches so I give full bags to people, but it seems that I have not been able to find a way to do so that is in line with my attention to quality.

Only recently I have been trying with smaller batches (~7 oz.), which gives me more control of the roaster (still not as much as large commercial roasters). With low drop temps (315F) and good application of heat, I can get a 12:30 roast time that seems to be better. Luckily I can apply the exact same amount of heat to the small batches as I did for the large batches for the beginning of the roast, which allows good drying times and development through the middle phase, and further lower the temp so there is enough energy to take it into crack but not go over board.

I am still waiting on a batch to age for a few days so I can really see how it develops (I tend to get too excited and make too many decisions based on early analyzes, which do not always pan out in the way I thought they would). I am worried that I will still experience some of the degradation of flavors over time. If things are going better I will post my profile graphs and we can discuss any ideas and thoughts about roasting particularly on this machine. However, even if you do not have this machine, your input would be appreciated.