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Hottop Coffee Roasterby Phil Jordan Roasting with the HottopA roasting session is initiated by pressing Start. The LED for Setting "1" starts to flash. Repeatedly pressing the Setting button selects the roasting level desired, from 1-7 (if you go too far you simply end up starting at 1 again). Pressing Start for a second time then initiates the roasting process. The drum starts to rotate and the machine begins to pre-heat. You don't add any beans at this stage! After about four or five minutes the roaster is heated to its pre-determined start temperature. The control circuitry announces this to the user via a clearly audible beeping noise that continues for around a minute. Don't worry, you won't miss it. Pour your measured quantity of beans in through the loading chute, replace the lid and wait. That's it. Well, not quite. The roaster will happily terminate your roasting session for you as soon as it determines that the pre-programmed end-point that you selected has been reached. However, you soon realise that to get the best results, you are the best judge of when to terminate the roast. For this reason, most users simply set the roaster on setting 7 and then wait for the roasting signs (cracks, smell, less often colour) that indicate that the roast is ready and at the stage that they were seeking. At this point they press the Eject button and the roast is terminated. When the roast comes to an end, either automatically or when the user manually intervenes, a small solenoid-operated trap-door at the rear of the drum is opened and the beans are dumped into the cooling tray. At the same time, a stirring arm in the perforated cooling tray starts turning, stirring the roasted bean mass. A fan is mounted under the cooling tray and this blows cool air up through the beans as they are stirred. The arrangement is most effective, and the beans are cooled to room temperature after about four minutes. The roaster then beeps at you again as it did at the beginning, signalling the end of the roasting session, and everything stops.
That's it! Job done! Initial ExperiencesRemember, I had no real previous experience roasting my own coffee. I'd had a quick play with a popcorn maker and decided that that seemed hard work to do it right - I'd nearly cremated a batch of Lintong in around four minutes! So I was well positioned to understand how a complete beginner would fare roasting with a Hottop. I was a complete beginner! The answer is : like a duck to water! The Hottop is an ideal machine to learn roasting on. It's so easy to hear, see and smell what is going on. I immediately learned what first crack and second crack sounded like, and was able to start judging exactly how I liked my coffee roasted. As soon as I got a good supply of beans in stock, I was happily trying my hand at blending as well. I was very happy. I started logging all of my experiences when roasting too, in pursuit of a better understanding of my roasting results and also particularly in pursuit of repeatability. I bought a cheap stopwatch for timing. One thing I soon found was that I couldn't always exactly repeat a previous roast. Some days, I could get to the same end-point with a particular bean to within seconds of that achieved on a previous roast. On other days, I could be as much as a minute and a half off. Why? Voltage sensitivityI soon understood a basic fact of life with electric coffee roasters: they are pretty sensitive to line voltage conditions. When I roasted at times when large domestic appliances in my house (such as the washing machine, oven, tumble drier, dishwasher - you name it!) were working, I would find that my roasting times were extended by a minute or two. I tried measuring the line voltage being supplied to the roaster and soon came up with the following information :
I researched this issue of voltage on the Internet. I was able to find out that European convergence of supply voltages was intended to cause all countries to be supplied with a pan-European standard voltage of 230V, and that that convergence should occur in 2003. I am writing this article in late 2003 / early 2004 and it doesn't seem to have happened yet - at least not where I live anyway. These findings were a concern. One the one hand I was finding that my Hottop (in fact, all electrically powered roasters I believe) was really quite fussy about the line voltage and that seemingly small variations could cause quite a big difference in the end results. On the other hand, my roaster was (quite sensibly you would think) rated for the European standard voltage of 230V, 10V adrift from the actual voltage I was feeding it. Clearly I was not obtaining the roasting results that the designer intended when he programmed the roasting profile. What to do? Resolving the voltage sensitivity issueI went out and bought a second-hand variac. This is a Claude Lyons Regavolt, a very substantial piece of laboratory equipment indeed, rated at 10A. New items of this type that I looked at on the Internet cost between GBP300 and GBP400 (say very roughly between 400€ and 550€). I got mine for GBP40 from Telford Instruments, plus another GBP20 for next day shipping. I then went and spoiled everything by buying a Fluke 77 meter to monitor it with (around GBP150 I recall). Using the variac I have been able to play with the supply voltage to my heart's content. After lots of playing, I have come to the following conclusions:
Good news on voltage sensitivityAs a result of my experiences being shared with the new UK (and possibly European) distributor of the Hottop, I am very pleased to be able to relate that all machines sold in the U.K. from now on will be rated at 240V. Machines sold into Europe will be rated at 230V. So you've no need to worry about all of this if you're planning to go out and buy a new Hottop. I've related it all for the sake of interest, and also to demonstrate that you do need to be a little careful what else is going on in your home when you choose to do some roasting. Also, the manufacturer claims that the current control chip logic is much less sensitive to voltage variations than the original one I was supplied with. However, I still think it's best to play safe. Other notes on repeatable roasting and living with the machineOne other factor that affects the roast profile is how hot the machine is when you start the roast. Second and subsequent roasts are always slower than the first roast. I have heard it said that this is something to do with the machine incorrectly performing the pre-heating cycle on roasts where the machine is already hot. I cannot comment on this (although I really ought to do some temperature measurements to test that theory). However, it remains a fact that subsequent roasts seem to be performed to a different profile to those performed in a cold roaster. That said, a professional roaster friend of mine tells me that a cold roaster always roasts differently to a pre-heated one, although I suspect that the effect he experiences on his big professional machine is the other way around to the one I just described. Domestic issuesThe principal domestic issue in my household is that my wife and daughter complain vociferously if I don't have a fresh supply of wonderful, fresh-roasted coffee! That said, there is one minor domestic issue. Let's face it: coffee roasting generates smoke. The darker you roast, the more smoke you get. You can't get away from it! The Hottop roasts a largish batch of coffee for a domestic roaster. The smoke filter does a wonderful job in reducing the offensiveness of the smoke. However, you are going to get smoke. If you can't handle that then home coffee roasting is not for you. Personally I roast in the kitchen and just make the family put up with the odd bit of smoke now and then. However, if I was worried about this I'm told an extractor fan does an excellent job of clearing what smoke there is. Alternatively, roast in the garage or the shed. It's up to you.
Where next?I've had my Hottop for around 15 months now and I simply couldn't imagine being without it. I've roasted all sorts of absolutely top notch coffees and I'm generally speaking thrilled with the results. In search of repeatability, I have purchased a thermocouple and meter so that I can measure the temperature in the roasting chamber and terminate the roast based on measured temperature. It's good fun to play with this sort of thing, and it probably improves my roasting results in certain cases to a slight degree. It also enables me to play games with altering the profile the designer programmed into the machine. Another way of altering the profile is to use a slightly larger charge of green beans. The Hottop is allegedly quite capable of taking (at least) 300g of green beans. The only issue is that this slightly extends the roast. However, in some cases this can be helpful, as mentioned above regarding the Kenya Mika and the Colombian La Manuela. So you don't need to buy a variac! The other issue you should take note of is cleanliness. Coffee roasting (especially when roasting dry-processed coffees) has chaff as a by-product. This accumulates in the drum. Most of it falls into the chaff tray and can then be removed. However some of it collects in the drum housing. It's fairly easy to blow this out using an air duster (obtainable at most computer or photographic shops). Also, eventually you'll find some pieces of bean eventually get trapped in the drum. If you don't get rid of this stuff it will char and burn. At best this can taint the roast. At worst it could cause a fire.
Look after your roaster and it will continue to give you excellent coffee. I intend to report on many of my other findings and experiences resulting from playing with Hottop. However, for the moment I'm just too busy roasting coffee! ConclusionAfter 15 months of living with a Hottop, I can only say that it's an absolutely top notch machine. Anyone who wants to roast their own coffee and doesn't want to fuss about building a barbecue roaster (not all that practical here in Northern Europe anyway!) or some sort of mucked-about computer controlled popcorn maker (sorry Mnemonix!) could do no better than simply to go out and buy one of these. I have had only two issues with mine during its life. Firstly, I learned about voltage sensitivity the hard way. This should not worry new purchasers as all machines imported to the UK & Europe will be correctly manufactured for local voltage conditions. Secondly, after about 10 months the stirrer motor on my cooling tray failed. Hottop replaced it immediately, without question, sending me a replacement direct from Taiwan by FedEx so that I was up and running again in about 3 days. How good is that? If you can spare the cash, go out and buy one. I've never bought roasted coffee at all since getting mine, and frankly I can't imagine doing so again (even if it was from a really good roaster like Hasbean, Hill and Valley or James Gourmet Coffee). Outstanding! Web "Bibliography"Some interesting stuff by Randy Glass, one of the people who helped with the Hottop testing programme: From Sweet Maria's And of course not to forget the manufacturer's own site: 2008 Update: Hottop KN-8828P Coffee Bean Roaster First Look Tags: hottop |
