by JonS » Tue Jul 22, 2008 7:48 pm
I still haven't made my mind up about the Hottop "P" At some point I'll probably post separately about this, but I'm still getting it all straight in my mind. I have a "P" I upgraded my old model hottop earlier this year.
Credit to Hottop, it does almost everything it's supposed to, but it's not terribly hands on, and in that respect, I think the "B" model might actually be better.
What the "P" is designed for I think, is "profiling" roasts. That is basically mapping out how the temperature changes over time, and storing that as a program, to be repeated in a hopefully very similar, if not identical fashion, again and again. Seems pretty straightforward.
I'm not sure whether I'm alone in this opinion, but the idea of breaking roasts down into time-based segments, dealing with the thermal inertia of the element, the natural rate of temperature rise in the roaster, and deciding whether to deliberately engineer things to make the hottop "miss" to force the element on permanently, is not always intuitive. Then you have to run the program and check whether it gave the changes you wanted when you wanted them. However, once you have done this, and saved the program, you at least have a reasonable chance of repeating the process later, assuming a similar ambient temperature, supply voltage, bean mass and moisture content.
The "B" model however, relies more on manual adjustment of the heater power, which is what governs the rate of temperature change in the hottop. You have direct control over the main input affecting the rate of temperature change. This, and the fan speed control, are basically fancy equivalents of what folks have been doing modding the old hottops for years. And it's roughly equivalent to the hands on control of a Gene Cafe, but with the advantages of the hottop design and a last program memory. There's a learning curve here as to what changes to make to the heater power (and therefore the rate of change of temperature) over the course of the roast, but the fact that you're doing it on the fly, and the fact that instead of worrying (as you do with the "P" model) that if the controller decides to turn off the heater completely, you're going to have trouble turning it back on again any time soon because of the thermal inertia. Instead, stick the heater at full or near full until just before 1st, then drop it back to keep 1st in check, then maybe back up to take you through to second, and it seems altogether more interactive and hands on.
I've been thinking about making a manual heater control for my hottop "P" to spend some time with the more hands on approach and see how it works for me. Probably do the manual fan as well, although this is not as important given the already programmable nature.
Ultimately, the key thing with roasting is to develop a feel for the roasting process. Different beans require different roast profiles, some more different than others, and whatever you buy, there's no substitute for time spent making notes and understanding how the roaster and the beans behave.
My personal opinion, is that rather like choosing an espresso machine or a grinder, good tools are always a help, and a pleasure to use, but it's the effort you're prepared to put in that will make the difference between success and failure.
The one nice thing about the hottop "P" and "B" models though, is that they offer an auto mode rather like the original hottop, which can be good for getting you started with them before you're ready to explore further.
I think the most often-stated downside to the hottops is that the temperature readout is based on drum, not bean-mass temperature. The relationship between the two changes throughout the roast, there's not an easy way of mapping them. What you do have, is the use of all your senses and careful note-taking to decide what's happening with the beans, and the points and rates at which these changes occur, to help you make decisions during the roast.
If you buy a "P" or "B" hottop, I doubt you will ever have to mod it. The basic one, well, I think you might eventually want to mod it (or at least officially upgrade it to a "P" or "B") But in terms of the general quality of the roasts, I think they're very good to excellent. Though I wouldn't say no to 500g capacity!
Jon
Iberital L'Adri 1grp semi-auto | Macap MXKR Auto | Mazzer Super Jolly | Hottop Programmable
Isomac Zaffiro w/PID | Isomac Gran Macinino | Mazzer Mini
Scace Thermofilter
Custom-built grinder timer