For the lightest brewing roast, stop as the first crack winds down. Pick the moment as follows: during the first crack, you will smell a vinegary and grassy aroma coming off the beans. Stop as soon as that stops -- this is the lightest usable roast. If you do not dry the beans well, this will happen as the second crack starts. If you spend three to four minutes ramping the beans up to 300F (measure where the air exits from the bean mass), you will be able to stop roasts right at the end of the first crack.

For espresso, if you have a proper drying period, you can stop just before the first pops of the 2nd crack, when you start smelling caramel. If the drying period is short, you need to go to the beginning of a rolling 2nd crack.

As you see, a long drying period does not help for full city roasts and beyond, but it stretches out the range of useful lighter roasts. The advice to newbie roasters to take brewing roasts to the first pops of the second, and espresso roasts to a rolling second, is based on getting the beans into the comfort zone of air roasters that heat up too quickly for light roasts.

A longer ramp from 300F to first crack will accentuate the woody, bready, nutty and malty flavors at the expense of sweetness. If you like flavor notes akin to barrel aging wines or spirits, this is not a bad thing to try. You also need the right sort of coffees, Indonesians and Bourbon cultivars usually work. But if you want a lot of acid and enough remaining sweetness to balance it, e.g. you are roasting a fruit bomb coffee like a Sidamo or Hue-Hue, going through this part of the roast fast is your best bet.

I see. Thanks for the clarifications, Jim. I appreciate you taking the time to respond. I roasted tonight with this in mind (5 min drying phase to 300 and then a fairly quick ramp to 1C at about 8 minutes. Done in 11.5 minutes at the first sign of second crack. In a couple days, I hope to see if this has helped).

I tried to pay closer attention to the smell as you described but frankly, it just smells like popcorn and bread crust above ~350F to me at this point. This is something that hopefully comes with a bit more roasting experience.

Jim's advice is sound, to be sure, but also take into account how your roasting setup is unique and may not register temps in lock-step with what is provided. IMHO it's more important to get consistent readings for your setup than it is to shoot for any suggested temperature target. If you are consistently hitting 1C at 375F regardless of bean load, regardless of how close you move the HG nozzle, then you know that's how your setup behaves. Plan accordingly. This is the double-edged sword of a DIY setup - there's a lot more "Your Mileage May Vary" involved, and experience will be your best teacher.

Also, bear in mind that it may take a LOT of roasts to get in the ballpark of "consistent" & "acceptable". That 8 lb. "sampler" pack? It'll be gone in a week. You'll be playing with bean loads, charge temps, ramp tweaks and so many other variables that can easily consume your first 30+ roasts. The DIY path is NOT for people who want immediate & good results. Consider the subjective tone of anyone who tells you that you can get "great" results "immediately" with a DIY setup. I continue to have a great time learning on my HG/BM and can produce results to my satisfaction (and have the ability to tweak heat input to play with profile times), but it's taken almost a year to reach this point and I've roasted, drank and burned through almost 60 lbs. of green, in addition to regularly calibrating my tastebuds against some well-regarded local roasters. Then again, I may be a slow learner .


*throws 2 pennies into the pond*

-s.

Whale wrote:Wouldn't the release of vapor be considered exothermic?

As you stated the energy is stored in to heat moisture and when the vapor is released, the energy is released as well. This is an exothermic reaction. Is it not?

In the case of liquid water turning into steam the answer is no. This is a physical transformation, not a chemical reaction. Burning of coffee beans is an example of an exothermic reaction where carbon compounds combine with oxygen to form carbon dioxide and water,releasing heat.

Sherman wrote:Jim's advice is sound, to be sure, but also take into account how your roasting setup is unique and may not register temps in lock-step with what is provided. IMHO it's more important to get consistent readings for your setup than it is to shoot for any suggested temperature target. If you are consistently hitting 1C at 375F regardless of bean load, regardless of how close you move the HG nozzle, then you know that's how your setup behaves. Plan accordingly. This is the double-edged sword of a DIY setup - there's a lot more "Your Mileage May Vary" involved, and experience will be your best teacher.

Also, bear in mind that it may take a LOT of roasts to get in the ballpark of "consistent" & "acceptable". That 8 lb. "sampler" pack? It'll be gone in a week. You'll be playing with bean loads, charge temps, ramp tweaks and so many other variables that can easily consume your first 30+ roasts. The DIY path is NOT for people who want immediate & good results. Consider the subjective tone of anyone who tells you that you can get "great" results "immediately" with a DIY setup. I continue to have a great time learning on my HG/BM and can produce results to my satisfaction (and have the ability to tweak heat input to play with profile times), but it's taken almost a year to reach this point and I've roasted, drank and burned through almost 60 lbs. of green, in addition to regularly calibrating my tastebuds against some well-regarded local roasters. Then again, I may be a slow learner .


*throws 2 pennies into the pond*

-s.

That's the truth! I just bought a 4 pound sampler pack and am almost through it already. I'm also seeing that even with a relatively small batch size, I probably need to roast through at least a pound of something just to figure out where it should be roasted, let alone tweaking the roaster. I should probably be buying bigger bags of beans.
I do have to adjust the temps most people talk about. I think I'm measuring air temp more than bean temp (or my thermometer is off). First crack usually comes at about 450F in my system.

Sherman is right about temperature measurements -- the first order of business is getting ones that are useful, not necessarily ones that are true. To be useful, they need to

• rise monotonically (i.e. no dips) as the beans heat (at least after the initial drop in/warm up)
• be at roughly the same temperature for the milestones -- brown beans, first crack, first pops of second -- roast after roast. But be aware the second crack comes at lower temperature in slower roasts.

In practice, your measurements are some weighted average of the beans' temperature, the heating device's and the ambient air's. As long as the weighting and your roasting procedures remain consistent, you're in business. If you reposition the sensor, the weighting changes, and the new readings do not compare to the old (although they can be better). If you change the heat gun settings or distances, it's the same story. In short, do not expect that the milestones will remain the same if you tweak your roasting setup; and give yourself ample time to judge the results of any roasting changes.

another_jim wrote:In practice, your measurements are some weighted average of the beans' temperature, the heating device's and the ambient air's. As long as the weighting and your roasting procedures remain consistent, you're in business. If you reposition the sensor, the weighting changes, and the new readings do not compare to the old (although they can be better).

Which brings my question: Where should I put that bean temperature sensor? My only reference for the question is the picture that Jim has posted on the Quest M3 thread

(Another airhead drums: Initial Impressions of the Quest M3)

In the M3 it seemed that the sensor was indeed inside the the drum but would only contact the beans occasionally. Given the fact that the drum is rotating there is not that many practical points, but I was thinking that the "ejection door" (for lack of the actual name) could be the spot where there would be the most actual contact with the beans.

Is this contact with the beans important? Can I correlate an internal temperature of the drum to a beans temperature?

Disclaimer: I am just starting the preparation work. I have not started to roast yet but I am gathering "stuff" so a little understanding of the actual important factors will help me.

If you feel that I have not read something that I should have, please just post a link and I will read on.

People contemplating home roasting have to decide exactly what it is that they want to accomplish.

This is such an important statement that I chose to put it in bold, italicized type.

If your goal is to get the sort of professional results that the most respected roasters obtain, with their ultra large and expensive equipment, then that goal is simply and clearly out of reach for 98% of the people who will home roast. In order to get that sort of result on a consistent basis you can just about forget using any of the popular, relatively inexpensive home roasting devices out there. You will either need to start with something at the upper end of home roasting equipment, and severely modify it, or you will need to buy professional type roasting equipment that will cost you several thousand dollars on up.

If on the other hand you want to obtain results that vary from acceptable to very good, but which are probably inconsistent, you can do this with upper end equipment, a focus on detail, and a lot of hard work. Home roasters obsess about a lot of detail, much of which they can't really control, and using the sorts of equipment that they own, it doesn't matter all that much anyway.

So decide what you want to accomplish and then go from there. The most accomplished professional roaster in the world would have great difficulty producing world class roasts from a bread machine or a Stir Crazy or a Hottop, or ________________ (you name the popular home roasting device).

This is not to say that you shouldn't home roast, or to say that you should accept that you will produce crap. But it is to say that unless you have the requisite level of equipment, and a lot of time and money you are willing to devote to the process, professional results are going to elude you and perhaps the focus should be more on getting good to very good results, with reasonable consistency, then it should be on some pipe dream that if only you can control your measured temperature to within 0.01C, that the results will magically appear.

ken

On Ken's post: This is somewhat inaccurate. It's not about the professionalism of the roaster, but about the characteristics of the coffee. You can roast some coffees, for some uses, even on the poorest equipment. Harars, Yemens, and Brasils to a rolling second crack, or Indos to a Vienna or French roast, can be done with just about any roaster. Check the homeroaster's list from a few years back, and these will seem like the "best" coffees.

The lighter the roast, or the more acidic bean, the better the gear has to be, to get the most out of the bean, i.e. a roast sweet enough not to flatten out the highlights that make that bean distinctive. Very few professional roasters, even among the very best, push this envelope; since most of their customers expect coffees that taste like coffee, i.e. medium roasts with lots of caramels and roast flavors. For espresso only, I could probably get away with less expensive gear and less measurements; the timing and precision constraints for roasting an auction coffee for brewing has the toughest constraints.

On Sylvain's Post: When youy measure temperature, you measure the air. To get a good value for a bean temperature measure, you are looking for air that is as close to the bean temperature as possible. By simple physics, this is the air that has been in contact with the beans as long as possible. So don't put your sensor insiude the bean mass where the air is entering it; put it in the spot where the air is just leaving the beans or has been in contact with them for longest.

In an air roaster, this is simple. You place the sensor just above the surface of the beans, where the air is exiting the mass. In a drum, this is usually close to the center of the drum (relative to the vertical view), and towards the end of the drum where the air is exhausted, which is usually the front, but not always. Sherman is still trying to figure out the airflow in a bread machine/heat gun set up. For those using a heat gun and dog bowl -- how good is your nose?

Thank you Jim.

I am looking at a setup with solid drum (sorta similar to the M3 but more archaic), thus the idea of the lower front portion of the drum where the door is to locate the sensor; most contact with beans but not necesseraly most contact with the air that has been in contact with the beans. The exhaust is forward and up, so the air flow will be minimum at the lower front portion of the drum.

Am I misunderstanding something?

If the air exit is Probat style, at the top front of the drum, measure at the top of the bean mass at the front of the drum. There you will (hopefully) get the air that has flown through the beans and that has equalized in temperature. Basically, probe position just above the door should work well.

I also believe in measuring the drum temperature (i.e. the hottest part of the roaster), since I find this much easier to control than the bean temperature. But most people seem to be able to live without it.

another_jim wrote:On Ken's post: This is somewhat inaccurate. It's not about the professionalism of the roaster, but about the characteristics of the coffee. You can roast some coffees, for some uses, even on the poorest equipment. Harars, Yemens, and Brasils to a rolling second crack, or Indos to a Vienna or French roast, can be done with just about any roaster. Check the homeroaster's list from a few years back, and these will seem like the "best" coffees.

There are people here trying to help other people, and that is certainly to be commended. And, there is enough competence floating out there in the home roasting community that by seeking advice on a forum like this, you can certainly learn the basics of roasting and how to become a better than average home roaster.

But it is important to retain perspective. There isn't a person who posts on this forum who has what I would regard as serious roasting experience. Roasting in small batches with a home contraption, or something you heavily modified, over even a long period of time, is not even remotely similar to being a really good professional roaster. There are no "known entity" pros who regularly post on this forum. Some of the other forums on this website do attract some real pros, but other than an occasional tangential post (like a couple from Mike Perry about which of his greens might be suitable for SO espresso) there is no pro input here. And simply having read a number of long roasting tomes and having memorized portions of them is no substitute for real, actual, experience, and the knowable track record that might accompany that.

I'm certain that I've roasted more batches and more pounds of coffee than 98% of the people who post on this forum. I've sought input from pros and others I respect, and found some of the advice I've received to be useful, which I've integrated into my technique. Still, I would be very hesitant to give more than the most basic advice to people using equipment I am personally unfamiliar with, which would be the vast majority of things that people on this forum use or have used to roast coffee in. And simply having a common sense understanding (or thinking one has it) about how a certain type of roasting device works is no substitute for actually having used it a whole hell of a lot, before being able to really give useful advice that others could benefit from.

ken

This too is not quite inaccurate:

• Doing the same thing over and over again in the same way, not paying attention and treating it as a chore, does not make it experience. Most commercial roasting is done like this. Ken himself has said most of his roasting is done like this.
• The added experience of commercial roasters comes from sample roasting and cupping. Sample roasters are more bulletproof, but otherwise comparable in controls, batch size and operation to the better home roasters. Even at Green Mountain, where they use multi-million dollar industrial bowl roasters with perfect controls, all the sample roasting is done on the ubiquitous little Probats (albeit in a beautiful gang of six), profiled by hand. Their ace in hole is Lindsey Bolger, probably the best cupper on the planet. Quite simply, it isn't the roasting equipment, it's the person roasting and tasting.
• Home roasters will become expert to the extent that they roast a lot of different coffees, cup them, and compare their roasts to the best out there. The best professional roasters have no problem selling their beans green and roasted, inviting comparison. Barry Jarrett used to, now Klatsch, Paradise, PT's, Terroir and some others do it too. Home roasters who regularly compare their roasts to these will soon become very skilled.
• So becoming a great roaster takes more than just roasting, it takes careful analytic tasting, a willingness to roast a wide variety of coffees, and a willingness for potentially ego deflating comparisons. Most professional and amatuer roasters are unwilling to do this; but those who are willing become good.

Jim

That is a wonderful summary of what I believe more serious home roasters should try to accomplish or at least set as a goal. It's certainly a glass (more than) half full philosophy and given only a limited amount of time and money for our hobby certainly far far better then the gloomy advice/lecture from Ken.

I'm just about to order some redline espresso for the first time along with some of their greenline beans to roast and compare. I've been meaning to try this blend for a while and I think today's blizzard is inspiring me.

I need to read this thread a few more times though it is not the funnest thread in the world, still it has great info.

There is so little out there to find on just basic profiles and at times I have wondered if men in black suits keep it that way. 2+ years with my Hottop B and some time with a point and shoot Behmor and a few hundred pounds of greens plus what ever I have been able to find here and there on getting the most out of my beans has been a great education. I am just a babe in the woods and yet I feel those that have great info hide behind the equipment issue instead of just giving info on how to get the most out of a particular bean or type of brew it will be used for. All equipment will have it's pros and cons and they will all behave slightly different from each other for many reasons but what does this have to do with getting the most from a bean if taking into account what the equipment is capable of doing.

I will be getting a 1kg Diedrich or Topper this summer, now I will have the equipment and there will be no excuse other then me. Where are the profiles being talked about if I have the equipment? How many people are really going to spend close to 10k on their home roast setup? I really don't believe that the equipment makes the out come better, tons of pro commercial roasters prove this everyday. The small percent of pro roasters that take roasting to it's extreme still are in business and need repeatability to keep their customer base, a home roaster only has to please a few mouths. So after I get my new equipment can I only speak to those that have a Topper or a Diedrich about what they do? I just don't buy that.

Jim, I really hope you can get your profile Article finished so that the mass amount of new roasters as well as us experienced novices can get more from our roasts. I do believe there is advice that translates to the varying equipment that will aid many to roast a better bean and keep the pros on their toes so that they have to advance their quality.

germantown rob wrote:I need to read this thread a few more times though it is not the funnest thread in the world, still it has great info.

How can you be sure that this thread contains "great info?" On what do you base that conclusion?

germantown rob wrote:
There is so little out there to find on just basic profiles and at times I have wondered if men in black suits keep it that way. 2+ years with my Hottop B and some time with a point and shoot Behmor and a few hundred pounds of greens plus what ever I have been able to find here and there on getting the most out of my beans has been a great education. I am just a babe in the woods and yet I feel those that have great info hide behind the equipment issue instead of just giving info on how to get the most out of a particular bean or type of brew it will be used for. All equipment will have it's pros and cons and they will all behave slightly different from each other for many reasons but what does this have to do with getting the most from a bean if taking into account what the equipment is capable of doing.

Actually, the equipment talked about here for coffee roasting, other than similarly designed commercial drum roasters, is hugely different, varies enormously as regards the capability of controlling roast parameters, and has such variation in the ways that temperature can be monitored that we could as well be looking for pointers on cooking salmon from a pastry chef.

germantown rob wrote:I will be getting a 1kg Diedrich or Topper this summer, now I will have the equipment and there will be no excuse other then me. Where are the profiles being talked about if I have the equipment? How many people are really going to spend close to 10k on their home roast setup? I really don't believe that the equipment makes the out come better, tons of pro commercial roasters prove this everyday. The small percent of pro roasters that take roasting to it's extreme still are in business and need repeatability to keep their customer base, a home roaster only has to please a few mouths. So after I get my new equipment can I only speak to those that have a Topper or a Diedrich about what they do? I just don't buy that.

Congratulations on your upcoming purchase. Please report back to us in a couple of years. If you really believe that this sort of purchase isn't that important, then why are you contemplating making it? If you really think that people posting here, using the sorts of equipment they have available, are going to be able to teach you very much about how to use completely different equipment, I hope that you will disprove this idea to yourself, from your own experience. Your time would be much better spent visiting the roasting operations of several commercial roasters you admire, and watching them roast coffee in person, asking appropriate questions as the opportunity permits.

Your new roaster, with effort, will offer you the kind of results that only a few here can dream about. This does not mean that it will come without effort. Good luck.

ken

Dear Ken,

Home-barista is a fantastic source for information and has helped many people in their hobby however serious they are. I find many of your comments, in a number of threads, negative and/or condescending and thoroughly unhelpful. Though it is fun to see a guy like you go over the top at times and makes for interesting forum reading, I think many of us would prefer comments that are encouraging and constructive rather than unsupportive and elitist.

Sincerely,

A home coffee roaster/barista.

Mitch

happytamper wrote:Dear Ken,

Home-barista is a fantastic source for information and has helped many people in their hobby however serious they are. I find many of your comments, in a number of threads, negative and/or condescending and thoroughly unhelpful. Though it is fun to see a guy like you go over the top at times and makes for interesting forum reading, I think many of us would prefer comments that are encouraging and constructive rather than unsupportive and elitist.

Sincerely,

A home coffee roaster/barista.

Mitch

Dear Mitch,

A comment like that should be sent as a PM or an email.

That having been said, you have to take what you can get from those who try to give you information, giving as much weight to them as you think their opinions merit.

If you think it is at all likely that you are going to get consistently great results from a typical home roasting appliance, then you should enjoy those results and not need to seek reinforcement or encouragement from anyone else. If you think it is likely that anyone who is not very familiar with your own particular device can give you specific information that will result in your roasts improving, then that is fine too.

If on the other hand you actually want to learn how to roast, rather than to feel encouraged, then you are going to have to put a lot of effort into it, yourself, and only the most general pieces of advice will prove to be truly useful, unless they come from someone with a whole lot of experience on your own particular device.

I wish it was easier than that, but it just simply is not.

A number of years ago I had a conversation with a well regarded professional, who used to run a cafe and to roast professionally. He was very active in the online coffee community at one point, although not recently. In my conceit as a new home roaster I asked him what he thought of home roasting results. He said most of them were "better than coffee that the home roaster could buy in a can at the local supermarket."

That's a lot more depressing than anything I've written here And I don't actually agree with it, as I find it too negative. But from the viewpoint of a real professional who knows more than most of us do, I think it is closer to reality than the opinion held by many home roasters concerning their results.

I'm going to leave this discussion because I don't want to offend anyone further.

ken

I see the standards of what people compare are from many sorts of modified classic drum roasters. Do they roast beans the best? If that is the fact then Ken is right and the Quest might be the only home machine with a close chance. So something roasted with different heat types will be different.
I think this forum section may not YET have all the right answers to the finer knowledge of roasting but the group effort keeps us moving forward. And it's all archived. We also have a dedicated moderator who just wants us all to get better, a major key.
One limitation I've heard from Pro roasters that makes them jealous of we can do as home rosters is having to keep a style consistency of a generally small selection. We get to roast anything we want anyway we want all the time.

Jim,
The following things would have been very helpful to me when I began home roasting (in 04), and are things I have not seen elsewhere:

1. A simple troubleshooting chart that relates defects in coffee taste to mistakes in roasting:
e.g. An extended roast time causes a flat dull taste.
You've tried to start this discussion multiple times above, but approaching it from the defect -> cause direction might be better for extracting this information and then using in your article.

2. What are we trying to duplicate at home? Go through the steps used by professionals once selection is complete. In other words, what steps are taken by the pros to identify the production profile? This could mean roasting multiple batches, slowly adjusting things, and judging results. As many have stated, maybe this is not feasible for home roasters, but would be helpful to understand how much is involved.

3. Tasting. What is good? Any gauge testing in an industrial environment depends on this. In our case, we are putting as much care and detail as possible into our roaster, profile, and measurements, only to check things with our palates that are mostly undeveloped when we start home roasting. To control the process, we need to get a circle drawn around the whole thing, which includes measurements on what's coming out at the end.

My goal was always to roast the best coffee I could with my setups, for my friends and me. So, to me the discussion on whether I can really taste and appreciate good roasts is completely my own problem. Things I can do to improve this will always be welcome! Thanks for your help.

Jim