noah wrote:Question: When planning out a roast profile, how can I go about subdividing the roasting phases to refine my profiling? For example, how can the phase from the start of first crack to the start of second be subdivided according to the results in the cup?

Are there any notable subdivisions to be made with any of the other phases (either after the start of second crack, or from 300 to the start of first crack)?

I'm a strong believer in the "KISS principle," which of course stands for "Keep it simple, stupid " I see no point in introducing needless complexity when none is called for.

Therefore, I would divide up the roast cycle into the following, notable landmarks and periods:

(1) Charge Temperature (e.g. what is the temperature when you drop in the beans?)

(2) Drying phase -- this is the first part of the roast and begins with charging the roaster and ends at roughly 300F, depending on how you measure it

(3) Pre-First Crack

(4) Initiation of First Crack

(5) Period between initiation of First Crack and end of roast, if you don't roast into 2nd Crack

(6) Initiation of 2nd Crack, if you get that far

(7) Duration of 2nd Crack, if you get that far

(8) Termination of Roast, which may follow either 5, 6, or 7, above

With the proviso that stalling the roast at any time is inadvisable, the goal is to increase temperature at a relatively constant speed (which will differ during the phases) during #s 2-7, above. As a general rule, you will go relatively slow in the drying phase, faster in #3, and fairly slowly from the initiation of 1st Crack (#4) until the end of the roast.

In more direct response to your specific question in the first paragraph, I'm unaware of the particular importance of any specific part of the period between the onset of 1st and the onset of 2nd, however the overall duration is very important. With regards to the question in the second paragraph, stuff happens very quickly after 2nd crack begins, and unless you have a particular goal in mind or you like very darkly roasted coffee, you are probably not going to be going very far into 2nd in any event. All you can do is to time how long you have been in 2nd crack, and follow the temperature changes. These two things, easily measured, are the most important.

I have not heard of any subdivisions of the time after the drying phase until the start of 1st crack, although towards the end of this period you need to watch the amount of "heat velocity" you are carrying into 1st crack. If you are still adding lots of heat just before 1st crack starts, the roast will have a tendency to "get away from you," e.g. to progress at a very fast rate making the control of the period between onset of 1st and the end of the roast "too short," and hard to control.

ken

coffee.me wrote:I'm not sure if the 350-375F range refers to internal bean temp or one that's measured with our bean TCs. I have not experimented with such a slow ramp, but that whole forum post is a very, very, good one IMHO.

Whenever you read something like the referenced post (from "buttwhiskers,") alarms should go off that make you think about the following issues:

(1) What is the "proof" of what is being said?

(2) What is the actual correlation between the chemical and physical changes cited, and what most people could taste in the cup? What sort of beans is this applicable to?

(3) Where is the temperature being measured?

(4) As a homeroaster, do I have equipment that is capable of being finely enough regulated/adjusted that I could even hope to follow whatever suggestions are being made?

(5) How am I going to test this idea personally so that I can confirm for myself whether it works, and if so, whether the time and effort necessary will be rewarded in the cup?

(6) Is such an approach practical for me to even try? If I'm, for example, limited to a batch size of 4 oz, to pick a number, how much time do I want to spend roasting coffee each week? Will the differences I might see as a result be worth the time and effort expended?

There are many beliefs and opinions that get circulated and recirculated in the coffee universe, including especially "online coffee." Some of these are true, but many of them, when subjected to real scrutiny fail even basic confirmatory testing. Three such opinions/beliefs that I have been involved in personally testing include the "deleterious effects of freezing on roasted coffee," "that rotary pumps make better shots than vibe pump driven machines," and that a shorter interval between the onset of 1st crack and the end of the roast makes for an inferior roast product. All of these things were scientifically tested with blind, paired, shots, with the assistance of Jim Schulman and a few other people. Of the 3 widely held beliefs, only the third was confirmed on blind tasting. I would submit that the vaguer the concept, the harder it is to test and to prove.

Therefore, I'd take most of what I read that infers subtle and poorly described differences, based upon a modification of technique (roasting or other) with large boulders of salt unless there is some actual "proof" behind it. Even if "true," the impacts may be small and as such may only be noticeable to a "super-taster."

ken

noah wrote:
Also, can a roast go too quickly through the 300-400 stage?

Yes, you can BURN the beans during this phase. I've had a couple of batches of beans where I really pushed the flame height on my drum during this phase, and the coffee tasted "burned." Jim S. happened to visit me recently when I produced such a result (with a batch of Wondo Bonko). We learn from our successes as well as our failures, if we pay attention. And it wasn't obvious to me that this was the cause of the burned batch, until I gave it a lot more thought during a subsequent roast session. Ever since I have been more careful not to overdo it during this phase, just to get to first crack at some arbitrary number of minutes. I'd rather be a minute "late" if I get behind, then to push the heat up so much and so fast (just to make the time landmarks I shoot for), since being "late" might flatten the coffee out a bit, but it won't make it undrinkable. Burning it will make you toss the coffee in the trash, unless you are like a few friends of mine, who can and do drink anything . . . .

noah wrote:While the exact progression of compounds may not be able to be mapped, cant we generalize along the lines of, for example, from 400-430, you have the best chance of maximizing acidic fruitiness, from 440 on, chocolates, etc. The general principle of 300-400 gives bready, nutty, and 400 to second crack gives chocolates is well known. But cant we further break this down, or is it so bean dependent that it is a fools errand?

First, you'd have to decide on whose "400-430" you were talking about, since any of these arbitrary numbers will mean very different things depending on your roasting equipment and where your temperature sensors are located. I think it is possible to think too much about this sort of thing. Most people will learn more about roasting if they keep things relatively simple. Initially, it is most important to learn how to identify the cracks, and to become comfortable with the changing appearances of coffee beans as they roast. As one becomes more accustomed to using a particular piece of roasting equipment, one will learn to correlate the measured temps (wherever they are being measured) with what is going on in the beans in the roast cycle. At this point, your "400-430" will hopefully mean something to you, even if they are just abstract numbers to me. Finally, you will achieve some sort of routine (to which Jim alludes in his own personal roasting approach) with which you are comfortable. You can then take that routine and apply it to different beans.

As an example, I roasted 3 coffees this afternoon, a total of 6 batches starting out with a pound of green for each. The coffees I roasted were Ethiopian Worka, Ethiopian Wondo Bonko, and a Bolivian Cenaproc I bought from the Coop 6 months ago. All the roasts took approximately the same total time (roughly 15 minutes), however the Cenaproc was roasted much darker, in the same total time. I know from experience with my roaster and where I have my probe situated in the drum, that 2nd crack will start within 1/2 a degree F from 435F. I roasted the two Ethiopians to 433, and the Cenaproc to 439. I did this because I have roasted these coffees before and have learned from prior experience with them. Although I generally don't like to roast into 2nd crack, I have learned that the Cenaproc is simply unsuitable as a single origin for espresso at a lighter roast level -- it needs 20-30 seconds in 2nd crack to be usable. Even then, if I had it to do over again, I'd probably not have bought the coffee, but it does serve a purpose as a counterpoint to all the Africans I drink most of the time.

To get back to your second paragraph that I quoted, you could try to apply the same logic to choosing wines, but I think you will find it similarly useless, from a practical standpoint. You would probably be much better off finding some flavors that you like in coffee, then trying to achieve them by the beans you choose to purchase, and the results you can easily get by varying simple parameters such as overall roast time, length of time between the cracks, and the final temperature (point in the roast cycle) that you roast to. Molecular approaches, although intellectually satisfying, seldom will get you anywhere with coffee, whereas relentless experimentation with simple stuff will usually point you in the right direction.

ken

Fullsack wrote:Most of my roasts, roasted to roughly 45 agtron in 12-14 minutes, reach the first crack at about 360 degrees and are dropped between 397 and 403 degrees. Four to five minute drying phase, four minutes between the first and second crack. I only mention these number to point out how wildly bean temperature varies depending on the placement of the bean probe. I'd be cautious putting too much emphasis on bean temp without strongly considering the other variables.

Measurements like this are extremely useful within the confines of your own roaster in your own location if you have the probe located in a logical and consistent place. This is a highly qualified sentence and bears rereading a few times to understand that all of this is relative to a particular situation. The way that I roast, I hit first crack around 423F. This is obviously a very fallacious reading, but that is what my digital thermometer reads when I hit first crack, and is due to the type of probe I'm using and where it is mounted, plus the fact that at this point in the roast, the bean temp is obviously very different than the probe temp. At this probe temp I cut the heat input dramatically and over the next 4-5 minutes the beans "catch up" to where the probe is, and by the end of the roast I believe the probe is measuring something very close to actual bean temp.

This level of certainty (whether or not I am right) is based upon more than 5 years experience with my setup, correlating what is going on in the beans (by sight and sound) with the probe, and taking into consideration huge changes I've made in my roasting approach over this same period of time. If someone else were to play around with my own equipment and input heat at a different rate at different times, then all bets would be off and I'd no longer have confidence in what I was measuring unless I had a chance to watch this person several times using this equipment with which I am very familiar.

Most of us do not have "dream" equipment, and although what I have approaches this more than what most home roasters have, my roaster still has significant limitations one has to overcome in order to use it to best effect. So none of this is all that easy, but if you pay attention to what you are doing, you will ultimately get the hang of it and will learn how to adjust those things you can adjust, in order to get the results that you hope to get (or at least close, I hope).

ken

noah wrote:I was intrigued and tried an adapted profile which would have reflected the principles said poster was advocating. I used Mexico Organic Chiapas Proish Coop greens from Sweet Marias, which has been excessively nutty in the roasts I did where I allowed an even ramp taking four minutes from 300-400F. I tried a profile where, after I hit 300, I flew to 350 as fast as I could (under 1 minute) and then took 2.5 minutes of a slow ramp to 375, then cranked it to hit first crack in another 30 seconds. The results surprised me: The nutty flavors were almost unnoticeable. This is not to say much of anything as this coffee is not one with which to do a lot of experimenting with as its flavors are so mild and subtle, so I cannot say that this profile had a positive or negative effect on the total profile at this time, but the muted nuttiness is a surprise.

Just a general thought worth considering.

Although I am no fan of the in-your-face blends produced by the marquee roasters, most of which are designed to be dosed in the range of 18-23g, I'd be the first to acknowledge that these same roasters are sourcing some of the best single origins on the planet, either directly or in cooperative buying groups.

If you look at what these top roasters are doing to make a name for themselves, you will see that they are not doing it with their roasting prowess. What I mean by this is that although they are competent roasters, their claims to fame is that they are sourcing the top coffees and using their skills at blending in order to produce roasted coffee that is regarded by most as among the best in the world.

You do occasionally read promotional materials from roasters who claim to be god's gift to roasting, employing meaningless terminology such as "slow roasted," whatever that means. Generally, the roasters who tout their roasting skills are unknown and are not regarded as being among the leaders in the industry. It is not uncommon to hear fans of Italian roasters say that what separates the Italians from everyone else is their roasting skills. These same people are unable to define what they mean by this, implying that it is some sort of secret process that is handed down through the DNA. They are also unable to explain why it is that these same Italian roasters buy some of the cheapest and most uninteresting coffees on the planet, in what appears to most impartial observers as being financially motivated. If these Italian roasters have an exceptional skill, it is that they can buy very cheap coffees and combine them in a way that the end product is drinkable. Notice that I said "drinkable," not "exceptional."

Roasting properly is a skill and it does take time to develop it. There is nothing secret about the process however, and the difficulty of doing it well would be of the same degree of difficulty as learning to bake bread.

There is a reason for the emphasis on the quality of the raw materials. That reason is that roasted coffee is at its core an agricultural product in the same sense that wine is. When it comes to assessing the percentage of end product quality that comes from the various stages of its development, the overwhelmingly most important factor is the bean quality in the case of coffee beans, and the grape quality in the case of the wine. The winemaker can make things worse, and maybe in marginal situations can improve things a tiny bit, but the care and feeding of the grapevines and the selection of the grapes on the sorting table will determine 90%+ of the quality of the finished product (e.g., the wine).

It is very much the same with coffee. By the time the coffee ends up in the 132lb sack headed towards the roasting plant, most of the potential end product quality has already been determined. Yes, you can surely diminish what came to you in the form of green beans, but your options for actually improving upon them will be fairly limited. If you look at what the high end roasters are doing, they are not doing very much special in the roasting plant, and they are concentrating their efforts on visiting the various origins in order to develop relationships with the best bean growers.

If what you want to do is to improve the quality of the coffee you drink, then of course it will help to learn the basics of roasting, especially what not to do that can destroy the value in the green beans you have purchased. Most of the improvement that you can hope to get in the cup will come from buying the best beans, rather than from modifying various roasting parameters in an attempt to improve the potential that is inherent in the beans themselves.

ken