I did a lot of profiling experiments when I was getting up to speed on the Quest M3 (QM3); I did even more when I was designing the ramp controller for my air roasting set up several years ago. These profile comparisons showed that very small profile differences made for very distinct differences in taste.

This variability was borne out in the roasting competitions, where entries using the same coffees, roasted to the same level, sometimes even on the same roasters, tasted very different.

So if small profile changes make for big taste differences, what are the chances of getting indistinguishable tasting coffees from two completely different roasters (machines), using completely different profiles? You'd think there is no chance, instead it can be close to a certainty. All you need is that the same roaster (person) does the roasts to suit his or her own tastes.

After not using the air roaster for a 18 months, while learning to use the QM3, I decided to do a comparison between the two machines. I wanted to prove to myself once and for all how much more interesting and complex my QM3 roasts tasted, and that I had spent the grand for the roaster wisely.

I roasted two brew coffees, one light, one dark, and two espresso SOs, also one light and one dark. I did this set of four roasts on both the air and drum roasters, using my favorite profiles (10 min for brew and 11 for espresso on the P1 air roaster, a few minutes longer and much more seat of the pants on the QM3 drum). I did not attempt to make the drum roast look like the air roast, instead I stopped the roast when it looked and smelt right. I was not trying to produce identical roasts, I was trying to produce the best possible roasts from each machine.

The light brew and espresso coffees tasted indistinguishable. The dark air roasts, both brew and espresso, were a hair more aggressive on the roast flavor, but so close it took several tastes for me to be sure I wasn't imagining it.

How is this possible? Simple. I obviously have a desired taste balance in mind, and my belief that I've mastered the roasters and gotten the best profiles simply means I can get that desired balance on any coffee I roast on either machine. So roasts from the two roast machines taste the same, since they both closely approximate an ideal I have in my head.

This means that profiling advice, at least mine, is probably quite subjective beyond a certain point. There are certainly incompetent roasters (people) and hopelessly bad roasters (machines). There are probably profiles that are simply too fast or slow for anyone's taste. But within these limits, it is the taster's sense of what is a good balance of flavors, rather than anything more measurable, or anything about the roasting equipment, that determines how ones roasts will taste.

For instance, Ken Fox's thread mentioned that Stephen Diedrich advocates a "slow start/fast finish" profile that is slower to the first crack and faster thereafter than the one Ken normally used on his previous drum. Ken spent a long time developing that profile to suit his sense of taste; so unsurprisingly, he thought the Diedrich profile was not as good. But other members who tried it liked it better than a "fast start/slow finish" profile.

So while it's probably a good idea, as a new home roaster, to start with a proven profile until one is comfortable controlling the machine; after that one should try a range of different profiles and compare.

I am very happy and thankful to read this post.

I also have an air roaster (P1) and a larger electric drum roaster (now, I will never even try to justify the wisdom in that purchase... ) and I must agree that both can be manipulated to produce a flavour that is optimal for me for every different beans. This (for me) of course requires a multitude of attempts because of my lack of proficiency and mastering of both roasters (machines).

Nonetheless, I never stopped using the P1 for 2 reasons; It handles smaller batches much better and of most interest to me, the flavour profile is definitely different.

Jim's post brings a valid question but I doubt that the answer is that straight forward. It is possible that the difference in taste that I am experiencing is because of the different size of batches. Which is not a significant parameter between a P1 and a Quest but is on the Poppery 1 and the Cafemino. On the Toper Cafemino, the batches that I do vary between 500 and 1000 grams, where with the P1 the batches vary between 100 to 250 grams.

I cannot say that I can taste a differences between 2 batch sizes, on the same roaster (machine) using (and controlling) the same profile. Changing the batch size always introduce variation in behaviour of the roast that is not always easy to predict and manage.

Anyway, back to the topic at hand. While I admit to still have much to learn in the roasting art and the coffee tasting, there is still some coffee that I definitely prefer on the air roaster (P1) and there are other coffees that I prefer in the drum, assuming that I try to get the best of each roast.

Acidic, fruity, coffees always come out brighter and livelier from the air roaster while the rich bass tone coffees (which are very hard to find these days for me) seem to bloom better in the drum...

Give me a few years and I will have another opinion, I am sure, but for now this is where I am.

another_jim wrote:
For instance, Ken Fox's thread mentioned that Stephen Diedrich advocates a "slow start/fast finish" profile that is slower to the first crack and faster thereafter than the one Ken normally used on his previous drum. Ken spent a long time developing that profile to suit his sense of taste; so unsurprisingly, he thought the Diedrich profile was not as good. But other members who tried it liked it better than a "fast start/slow finish" profile.

The biggest problem I had with trying to execute Stephen Diedrich's profile was the near-impossibility of actually doing it on the Diedrich IR-1 roaster I purchased which is installed in my garage. This is true of the installation I had done initially, and also after having the exhaust piping revised.

If I could actually execute the profile in a repeatable way, following Stephen's directions for the damper position, then I could evaluate that profile and compare it to results with the profile I developed over a period of years on my old sample roaster. Unfortunately, that (Stephen's) profile is basically impossible to execute in a repeatable way on the roaster I bought from Diedrich, at least at my altitude as the roaster is installed in my garage.

So it isn't so much that I had an old profile that I was in love with, which produced a result I was enamored with, that in the end I decided to duplicate on the new Diedrich roaster. Rather, I simply could NOT do Stephen's profile on his roaster in my garage, and the results from trying to get his profile on that roaster were all over the map, as were the profiles.

ken

I agree that it's all about understanding how a specific beans needs to be treated to get a personally desired result. Then it's understanding your roaster and how to execute that treatment. I believe this is possible with many types of roasters down to a fry pan and a wooden spoon. The difference being the degree of challenge of control for necessary treatment.

Thanks for this thread and comments! It is quite relieving and reassuring to me as I am going to be choosing a roasting equipment (hopefully) soon. Probably the choice will be between Hottop and Quest; it's good to know the power will be then in my hands and skill and learning abilities.