I just read David Schomer's article athttp://www.freshcup.com/where he comments on the importance of very precise temperature control in the brewing of espresso. His example is staying within three tenths of a degree error. As a new coffee roaster this year, I have tried to follow in the steps of the pioneers, whose air roast profile recommendation seems to be: 2 minutes to 265 F 10 degrees / minute rise to 295 F 30 degrees / minute rise to first crack 10 degrees / minute rise to second crack. I use a Variac with a split wired 1500 Watt popper to try to achieve this. Of course, because I don't use a PID controller, I get some variation from this profile. Has anyone satisfied themselves on how much variation from this will adversly affect the coffee taste? I suspect those using heat guns, grill/drum, convection oven/stir crazy, or other methods will find this irrelevant and extreme, but I know there are still some people out there using poppers and trying to control the profile by hand. How much do you allow your temperature to vary from the ideal? Dave S.
This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. You just do not know how tempted I am to suggest that it won't make = nearly as much difference as using a good grinder would, but I have way too = much self-control for that. :) -- Rick ---- 11/4/2004 6:03:40 PM Fair in San Diego, CA 62°F (16°C) - 44% RH Wind From the West Northwest at 9 mph (17:28:30) <Snip> ************************************************************************= ** The information transmitted herewith is sensitive information intended = only for use by the individual or entity to which it is addressed. If the = reader of this message is not the intended recipient, you are hereby notified = that any review, retransmission, dissemination, distribution, copying or = other use of, or taking of any action in reliance upon this information is strictly prohibited. If you have received this communication in error, please contact the sender and delete the material from your computer.
Rick.Farris wrote: <Snip> Besides, it's way too late for that - I use a good grinder now. Dave S.
How true Rick, good grinder a must. But I'll make it even worse. I've been a hardcore split wired boost voltage control follow those ramp rates profiler for a couple years now. (The FrankenFormer roast controller sprang forth from this home roast befuddled mind.;-) Toss it all out the window! Be one with the bean! Wokking produces great results with no dials or thermometers! But to answer the original question, the best way to know if varying ramp rate changes flavor is to try the same bean different profiles! And no, minor variations from target wouldn't be catastrophic, could be noticable depending on the particular palate, bean, time of day, position of celestial bodies... Or more accurately to answer the original question: vary from target as little as possible is/was the goal. Kona Konnaisseur miKe mcKoffee URL to Rosto mods, FrankenFormer etc.http://mdmint.home.comcast.net/coffee/Rosto_mod.htm
I still roast by my modified WB1. I have not variac and control my profile by roaster tilt/air flow. I am quite satisfied with my control and coffee. I can basically hit any profile my roaster can handle, but it has taken a couple of years to get in turn with my roaster. Sometime around 06:02 PM 11/4/2004, Maryann & Dave Schellenberg typed: <Snip> -- John Nanci AlChemist at large Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.dreamsandbones.net/blog/http://www.chocolatealchemy.com/
<Snip> IMO there is no ideal profile. I have done 2 minute roasts that were as good as or better than any long profile. I use many different modded poppers to give me different tastes. But one concept that appears to give me better results is a very fast initial heatup, often in a preheated popper. At the 2 minute mark, my "better" profiles are 350 to 400F infrared bean surface temp. Have you tried different profiles and what were your results? --
Actually, since I started using a Variac, all my effort has been in trying to achieve the "ideal" profile, which gives me a total roast time of about 14 minutes. Before I got the Variac, I used a popper at full power, and total roast times were about 6 minutes. Of course, my memory of the taste is no longer reliable, making comparisons with later results impossible for me. I confess to not approaching this in a very scientific way; each roast I do is of a different bean. I don't enjoy the roast process enough to spend a lot of time at it, but I do enjoy the resulting coffee. That's why I have relied on the reports of others, primarily those who do take a scientific approach. Ken Mary wrote: <Snip> When you get temperatures like that at 2 minutes, what time and temperature would you get to second crack outliers? I wonder how your infrared-measured temperatures would compare with my digital cooking thermometer, suspended vertically from a hole in the "butter dish". Compared to most of the temperatures I read here, mine would be about 10 degrees lower, e.g. first crack starts about 380 F for me, and second crack outliers at 430 - 435, which is where I usually stop. Dave S.
<Snip> I can vary the time from about 4 to 8 minutes total roast time to first snap of second. Most of my poppers are modified with separate air and heat controls. <Snip> I read nearly the same second crack temps as you do, but I generally stop at 420 to 427. First crack temps are subject to the profile, but start at 370 for medium (about 5 minute) profiles but both longer and shorter start near 380 to 390. Short 3 minute roasts likely have an artificially high surface temp. Long roast first cracks are delayed due to drying out the beans. --
<Snip> snap <Snip> I have tried so many poppers that I found a few that unmodified they work for different profiles. I have one that goes full city in 4 min, one at 6, one at 9 and one at 12 so if I want a different profile I just use a different popper. I used to use a timer and a thermometer, that is how I got the information about the poppers but once I found that they were fairly consistent I quit using the thermometer and the timer. I have the poppers marked and just grab the profile I want. I do have to say that since I made the Drum I mainly drum roast now, and I do use a thermometer and a timer when drum roasting. RK Ron Kyle rnkyle
Do I understand correctly that the thermometer measures grill temperature, and is not inside the drum with the beans? What sort of profile do you aim for, when using the drum? Dave S. R.N.Kyle wrote: <Snip>
If you are relieing on other peoples data, I would suggest getting that roast time down a little. I found MY ideal in the 11-12 minute range. Sometime around 08:27 AM 11/5/2004, Maryann & Dave Schellenberg typed: <Snip> -- John Nanci AlChemist at large Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.dreamsandbones.net/blog/http://www.chocolatealchemy.com/