Before we get to this week’s Ask the Alchemist I’m super pleased and excited to announce a new bean from Uganda
Uganda Kisinga, Organic, Direct Trade 2022. It has an incredible density of flavor. Instead of summarizing here, just go check it out. What is worth mentioning though is that it is a limited micro-lot. Also (ha, I can’t keep myself from talking about it) it is a prime example how growing conditions (the climate is drier) and a quicker turn around from pod to fermentation box, can affect flavor as these are the same beans as the Uganda Semuliki but the flavor profile is quite different.
Also, for those of you that have been intrigued by Ruby chocolate, this month it is what I have decided to offer in our Kit of the Month. I’ll supply you with everything you need, and the instructions to get that lovely color. This are of course from our unfermented Oaxaca Lavados.
Chocolate Making Kit of the Month You can get it as 2 or 7 lb and either subscribe to it monthly or just get it this single time. And we are making it dairy free.
Level: Apprentice
Reading Time: 12 minutes
I have been teaching a new staff person (hi Madie) about roasting and so I’ve been musings about roasting and teaching (foreshadowing, we will be announcing our next all day Roasting Seminar by the end of the month) and these questions give me a great springboard to, well, muse and talk about a subject I’m passionate about.
In the attached, are the temperatures mentioned air temperatures or bean surface temperatures?
All of my graphs show the surface temperature of the bean, or more specifically, the average surface temperature. The minor exception is the very first data point which is showing the air temperature (over 300 F) just before the beans are loaded into the drum.
I find it very helpful to think about roasting in the same way you would think about driving a car. In nearly all cases what you care about is speed of the car or how fast you are accelerating to a certain speed. Those are equivalent to the temperature of the beans or how fast the temperature of the beans are changing.
In almost no case are you concerned about how much the engine is rotating, i.e. the tachometer or the rpms. This is why we don’t really pay attention to the air temperature. There can be a loose relationship between the rpms and your acceleration or speed, but it is sketchy at best.
I’ve seen this in new drivers. “what should my rpms be to go 30 mph?”
As an experienced driver you know how impossible that question is to answer and also why it is simply the wrong question.. You know intuitively it depends on:
The car.
The gear you are in
Whether you are going up or down hill.
How many people are in the car
This is exactly why asking for an oven temperature or air temperature doesn’t work. Let’s just play the game all the way through and see if that makes the point.
“How much do I need to push on the gas pedal to speed up from 30 mph to 35 mph?”
“I’m not speeding up enough. How much more gas do I give it?”
“I see a speed limit of 40 mph. But what should my rpms read?”
Do you see what I mean? None of those questions have exact answers. You push on the gas and if you are not speeding up enough, you push on it more. Unsatisfying to someone learning to drive, sure, but it’s the reality of the situation. It really is ALL the same.
“I’m going to fast….what do I do?”
Uhm…..take your foot off the gas and if you don’t natural slow down enough, push on the brake until you get the response you need….but don’t push it all the way down or you will probably crash (ruin your roast).
Yes, it takes a LOT of practice but in the same way you drive now without thinking about all those things, so too will it be with roasting….assuming you have good feedback. That makes me think of a video I saw a few weeks ago about becoming an expert in something. Many people think it is doing it for 10,000 hours…but it is more than that. I know it is a little long, but you should watch it if you want to improve your roasting.
https://www.youtube.com/watch?v=5eW6Eagr9XA
In short, one of the critical things you need is feedback. Your brain needs that to complete the mental loop and do the magical things it does. This is why constantly experimenting in a home oven without knowing the bean temperatures will never make you an expert in roasting. Sadly, the same is true when you roast in the Behmor. Without knowing the temperature of the beans, it is like trying to learn to drive while blind folded. All you end up knowing is if you crashed or not. Without knowing what you did to fail or succeed, you are doomed to just doing the same thing over and over and not getting better.
I suspect many of you are saying some variation of “but all I have is an oven” and my response is that I feel sympathy but it doesn’t mean you can make it work any more than the best professional driver in the world can teach you to drive if you are blindfolded, the car is on cruise control and the course is constantly changing.
Ok, bringing this back home to the question, I hope it might now be obvious that the temperatures I give would NEVER be air temperatures (rpms). They MUST be bean temperatures as that is the only useful temperature.
The beans pop at 114c. I am afraid to roast post that temperature in the fear of burning the beans. Am i right that the beans will burn after that?
I literally have no idea where this idea came from. 114 C is 237 F. Even taking into account that maybe you don’t really mean burn, but instead mean over roast, my graphs are peppered with roasting profiles (which I know you have looked at since you asked about it) where I talk about an End of Roast (EOR) temperature above 250 and many times over 260 F.
Without ranting, what I want you to do is apply a little logic (is it still called critical thinking?) and ask yourself the very serious question of how could I suggest 260 F (127 C) if beans would burn at a much cooler temperature. The answer is that I wouldn’t.
This connects up to the 4 things you need to do to become an expert. Practice with intention at the edge of your ability. In this case it means getting over your fear or ruining or over roasting beans and experimenting and seeing for yourself if you burn or over roast the beans if you go beyond a certain point.
Failure is one of the best tools you have to learn something and if you are going to truly master something, you MUST make mistakes. Only then can you learn and get better.
Frankly, this question puzzled me so much I asked the person who posed the it where they got the question/idea as I wanted to get to the root of it, but alas they didn’t answer. Instead, they asked this:
In your opinion and experience, at what temperature do the beans pop?
So this is interesting on a couple levels. What I get from it is that the questioner knows they are not getting enough data and so their brain, subconsciously most likely, is grasping at the data they have trying to form correlations.
This is deeply dangerous because our brains will see patterns where they don’t exist.
To that end, I’m not going to answer this question directly in fear of putting out non-correlated data that might be misinterpreted in the future when taken out of context. But I’ll say this.
There is a VERY LOOSE correlation between beans audibly cracking or popping and the end of roast coming up. But here is the thing.
Not all beans crack.
Not all roasts crack
Sometimes roasts of beans that previously cracked won’t crack the next time
In beans that audibly crack, if you are drum roasting, with the approximate profiles I suggest (yep, so many caveats) the end of roast will be 3-5 minutes away.
Cracking or lack of cracking does not correlate to the quality of the roast.
Do you see why I won’t assign a temperature? It can happen, (if it does happen) and it might not happen, between 230 and 260 F. That just isn’t really useful information.
So the next time you hear a pop/crack, what I want you to do is think “huh, my beans popped. How nice.” And move the fuck on. If you REALLY need to, you can think “well, my roasting is progressing and will probably end a few minutes from now.”. Any more than that and you brain is just trying to screw with you.
I read beans need to have an internal temperature of 120c. How do you measure that? What should the air temperature roasting be?
Ok, there is indeed a touch of critical thinking going on here, but it didn’t complete and instead fell back on looking for data it thought it could use, i.e. air temperature.
Again, I asked the person where they got that information or impression and didn’t get an answer. I’m left not knowing if this was from some scientific paper where they were doing heat flow calculations or projections or they cut a bean open or whatever. All I do know is that it simply isn’t helpful data as there is just no practical way to measure the interior of the bean, on the fly, while roasting, with the intent of using that data to affect how you are roasting. It is nonsensical. It is akin to counting up the mile markers on the highway for a minute and then doing the calculation to see if you are going the right speed. You needed that information a minute ago. It isn’t useful to you now, 90 seconds later.
To my mind, it is only useful if it is part of an entire scenario and is noted as information that explains something but has the caveats that you can’t really use it. Let me make up such a scenario.
Again
THIS IS A FICTIONAL EXAMPLE AND NOT REAL DATA.
When applying a heat gradient of 25 C between the environment and the average measured surface temperature of a cocoa bean, when the later temperature was in the range of 130 -135 C, it was noted that for a cocoa bean of mass between 990 mg and 1100 mg, showed a temperature gradient from the surface temperature to the core of delta 12.3 C s.d. 0.7 C. Under such conditions, the chocolate made from such a bean showed a 97% degradation of the compounds responsible for the unpalatable astringent taste in raw cocoa beans. It is our conclusion that beans must reach an internal core temperature of 117.0 – 122.0 C (average 119.5 s.d 0.57 C).
Basically someone cherry picked data from a thermodynamic model of heat gradients with very rigorous conditions and tried to apply it in a very general way to explain why raw astringency goes away with proper roasting.
My basic response to this is to go back and note that when you profile roast, in a drum roaster, where the Development phase is 2-4 minutes and the Finishing phase is 3-5 minutes, your cocoa will have sufficient heat penetration that the resulting chocolate will no longer have an astringency associated with raw cocoa.
Note what I did there and what I didn’t do. I gave you times and temperatures you can use. I never claim to know the internal temperature of the cocoa. I never tell you what the air temperature is or should be. I give you a road map and let you, being an experienced and competent driver, apply the tools you have, to hit those way points in the windows needed to get you to your destination or well roasted cocoa that will make great tasting chocolate.
I really hope these various analogies have helped. That is what I’m here for. And as always, please keep those questions coming in.