As a new member and new to the craft I'm a little curious. I've noticed that not alot of people respond to posts regard roasting challanges/roasting help/tips. But when it comes to what type of roaster one has there are 30 something responses. I'm not looking to ruffle any feathers but it just seams like an "Exchange" involves sharing ideas and helping others because at some point others will help you. Is it because people don't know the answer? If that is the case maybe responding with a "I don't know" or "good question" or something of that nature so the poster knows. I've just found the barista forums have a little more open diologue and sharing of ideas and tips. This craft will only grow with collective advancement.
It seems like roasting is just what you feel is right based on the taste you want to achieve in the cup. It's a whole lot of experimenting and time to find out which method of roasting will work for that bean weight ratio to maximum capacity, processing type, and origin.
I compare it to baking a cake for the first time without a recipe.
I just started. Experiments in the home at first, then a love affair and a want/need to know more, then the big bags and the bigger roaster and so on. Some are lucky enough to get jobs learning under an experienced roaster, but I also feel luckier because I can make more mistakes.
Yes, everyone's proud of his/her equipment, but roasters seem to keep secrets of the art close to the vest. Roast profiles, and especially blends are part of those trade secrets. As a scientist, I am accustomed to more open exchange, but so far in roasting, it's pretty much OJT, unless you pay for technical training. I joined the SCAA guild and take the technical courses offered at the coffee conferences. Well worth the expense. A good investment to shorten the learning curve. However, I do get good free tech support from my roaster manufacturer.
Do you have a specific question we might help you with?
I absolutely understand the importance of trade secrets, blends, competitive advantage, etc. What I'm looking at is the general knowledge things, for example I have an artex roaster (4kg/hr) It is electric using convection heat. The manufacturer suggests a 190 degree drum tempurature setting but my research tells me 205-220 degree cel. is the most common starting point. Does this sound right? is the difference because of the electric vs gas issue? I've roasted a number of batches and had very good results.
I started roasting on a Zach and Dani's. Once I got hooked I got a 1lb Diedriech and went to the SCAA convention in California and took about 8 roasting and cupping courses. It was mental overload (not to mention caffeine) but the experience was amazing. I am continuing to learn and experiment with a goal of going full time in a couple of years.
NOw, that's a good one. I roast on a gas roaster. But I think the critical thing is knowing if your thermostat control is at bean temp or the drum temp. On my dietrich, the temp probe is bean temp. In this case, you dump the beans in at drum temp 400 degrees F.
the beans, being cooler will drop drum temp to about 169-180 F at 1.5 minutes, then they start taking on heat. If you get tipping(burnt ends of the beans) or scorching, your start temp is too hot, i.e., too much external heat applied too fast. Watch bean color- when lemon yellow, switch your airflow (if you have that control) to 50% to the drum (so as to not dry out the beans) and let the roasting begin.
Your finish temp will depend on darkness of roast, but try to finish in 14-16 minutes , bringing temps up 20 degrees F per minute. Keep a log of time vs, temp in 30 sec increments and your roaster adjustments. (this is called profile roasting). Cut heat at first crack and let reisdual heat finish roast for lt-medium roast. For darker roast, lower heat and extend time between first and second crack to 10 F per minute and dump at 425-445 F. Does this help?
WOW......interesting stuff! I've been doing alot of reading and was thinking I might have to do some modifications ie. The addition of a thermocouple to measure bean temp. Currently the temp is measured at a pre-exhaust outlet. This roaster is unlike traditional roasters (ARTEX TOSTINO)....which makes it a little more of a challange.....and it's imported from Italy...another challange in itself. I would have liked to have gone Gas, but the cost of hook up was as much as the roaster.
Your response is more then enough, it's great...I defintately have some work to do. It explains alot. I had a batch recently with what I now know were scorch marks (little black circles....indented and sort of carbonized) but yet the rest of the bean was a full city.
THe marks you observed are called volcanoes. There are almost always a few of them, but if you have a significant % in the batch, it means a too hot, too fast progression in the roast. They are caused by explosive volatization of gases from the beans. If you roast too fast, beans will be dark on the outside, but not roasted in the interior.
Tipping would appear as burnt ends; scorching would show as dark stripes or zones on the beans from too hot early in the roast.
You should try to take some courses in roasting.... Good luck
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