To Whom It May Concern


#1

A thread for tips/answers. Often times I have a hard time remembering all that I feel is important and perhaps I’m even worse at writing them down in a clear concise way. So I thought I’d start a tread where it is all random an nonsensical-like. Beginner to pro tips and tricks for roasting or whatever, like how I like to drink two cups of water when I wake up before my coffee…you know those sweet sweet tips that make it all a little easier :wink:

  1. A 27% majority of flavor shift can happen by moving where (by minute) the profile moves through yellow. For me yellow can happen in the range from 360F - 430F, for the Marshal Ethel profile I like to cross 400F in the 5:00-5:30ish range while ideally then adjusting so the profile hits first crack some 10-30sec before the last segment.

Hope that helps, to all you coffee nuts out there burning coffee in the pursuit of flavor and knowledge, I salute you. That is all, Good day Gentleladies and Laddies.

For you, something to hear, something to feel: https://youtu.be/hdFeQ5oi5fY


#2

Generally roasting profiles (for me) on the IKAWA is decided by hard/soft bean and more/less porous. Washed beans tend to have larger pores or at least need more heat in the profile than dry processed beans. It is said that decaffeinated beans have even larger pores and take on more color than washed, dry processed tend to take on color the least. Soft beans like those from Brazil, need a lot higher temp in the beginning to roast well, but if not managed well can burn out before flavors develop or the desired roast level is achieved. I have a working theory that from the start they need to get up to, at least, a yellowing temp within a minute or two and spend plenty of time being a yellow color (for chocolate notes). Hard beans are able to use a much more “gentle” profile. Meaning that they absorb heat much easier at lower temps, and hold on to the heat during the roast.

I think it would save a lot of time and increase our understanding if we talked about beans by their cultivar name aka variety and then where they came from, which allows for a quick synopsis of the physical characteristics of the bean. An also would create awareness that roasting a blend of varieties is different than a single variety.


#3

Following my previous thought about beans and cultivars…roasting multiple different bean varieties together is a difficult task on the Ikawa. I believe this inherent issue stems from the air roaster applying heat very precisely. And because the beans can be lofted quite well, all the beans are receiving the same heat together with little bean to bean or bean to wall interaction. So if you have multiple beans they usually would require different heat profiles for each variety, so even in a perfect roast, only one aspect of that green is optimally roasted. An easy solution, though, could be very expensive. Sourcing from a single farm, and single varietal, that extra complication is not ideal for me. I do not believe all weight loss is created equal and the profile shape is critical for the flavor/aroma formation. I think one way for all the beans to follow the profile is to roast with a relatively low fan, so heat can be distributed better to beans that take on heat differently in the mass, ideally trying to not overdo it on the beans that take heat the easiest or burn out sooner. But adding a low fan to a normal profile hasn’t worked out for me yet, a drastic change in the fan will need a different heat profile.


#4

Two thoughts:

  1. Crema of the brew (even espresso) is the direct relation of roast degree. Since I don’t have an Agtron (roasted color measuring device) it is somewhat hard to tell how deeply or light the coffee was roasted, but when I brew the crema tells me instantly if I was too light (cream color). This is interesting because sometimes I will roast and the results are super uneven: super light color but tastes burnt (tipping/internal scorching), or dark but I get that lettuce/cucumber or pea like flavor (it depends on the bean/origin).

  2. Low fan MAY be better for imitating the nature of a drum roaster. Since in a drum the beans are rotating and are semi-lofted in the air, the hottest part of the drum roaster is still the metal, and it’s not wholly unreasonable that there are larger temperature differences the beans experience. Unlike a consistent fan air roaster, ideally transporting heat evenly and removing heat differently thus making the differentiating variable the actual bean (its size, varietal, farm). So a lower fan will instead create a more cohesive mass, where the mass differs in temp from it’s contact with initial heat from the fan and walls from bottom to top as one unit, rather than individual beans varying how the single bean dances with the heat. Maybe this is why Micheal Sivetz roasted tons of coffee in 3 minutes or less.


#5

It’s not my intention to always roast an Ikawa like a drum roaster, but I like to use drum roasts as a lighthouse to determine how to roast, having that guide or goal allows for mapping of the coffee profile to occur. An also the ability to roast a coffee how I choose. Maybe this is just an effort in futility but I doubt that a) because sometimes I randomly get a good to great drum-like roast (which I make sure to note), so far there seems to be a correlation between a high spiked charge and also lots of chaff removal during yellow.

Which brings me to my main point…when majority of chaff is removed and how that highlights some aspect of the roast.

In the Marshal Etheo style profile tested and made by roasting dry processed Ethiopians (is also decent on other naturals) the sizzling sound that comes with the chaff removal (I call expanse) happens 30s to 1min before I hear first crack (1C), I see this as a sign that the beans in the roast is progressing as usual. Side tangent: people used to say that stopping the roast and having puffy beans is bad. I do not agree, it could be bad, emphasis on could, but to my understanding (tastings) it could go either way but is not a conclusion. As the beans roast, the bean cell structure (plant cell wall matrix) will go through a plastic (soft/malleable) phase then a glass phase starting during the expanse (when the beans sizzle and chaff comes off).
So back to my main point…while roasting wet processed beans this expanse (because of a higher heat during the green and yellow) this removal happens while the beans are still yellow. Is that a good thing? The chaff while on the bean acts like a shield, and in my view, is why the difference between air/drum roasts have the biggest difference.
Should wet and dry processed remove the chaff at the same time? I don’t know, and would not guess that it should, but the sizzle and expanse is a sure sign that the roast can be good, without it I can’t remember a good roast.

To all those determined to have a clear coffee (a clear cloudy-free coffee A Pour-Over Experiment: Clearer Brews ). Turbidity can be caused from plant phenols (correction: not just phenols but flavonoids), proteins and carbohydrates. So far, from what I have observed, the main determining factors, roasting lighter on beans that are harder (aka higher altitude), usually wet processed because dry processed still has dried mucilage covering the outside pores (also why they need less heat), with larger grinds and less agitation in the brewing, helps.


#6

Hi! I’m new here, but I wanted to say thank you for your many contributions to this community. I’ve read through a lot of the threads over the past few weeks and couldn’t be more inspired by what I’ve seen.


#7

@Corey, thanks, much appreciated!

It may be conformation bias but something I have wondered and is slowly unveiling as a pattern is: what is the link between roasting and cupping. When the cups go from hot to cold and the flavor transitions, if it transitions what does that signal to me.
So far, when the cup is hot, that is the center Edit: outside of the bean, how the bean was roasted in the furthest sections away from the hottest part of the bean. Now for intents and purposes heat is a variable of pressure so there is a lot to the above statement, but for this idea train to move along I will say it is the “hottest” part. In air roasting the hottest part is the inside and the coldest is the outside of the bean. Maybe those who who post “thermodynamics” in their course should actually know some (jab intended). But bristling aside, in air roasting we basically go from heating the inside out. -This is one of the main factors when reading how drum roasters do things and how to apply it to air roasting- (Almost always, it is to do the opposite, because we are using the other side of the coin to heat the bean) Essentially the more conduction, the more energy gets displaced to move in the apposing direction. Whew! So when we taste the cold cup that is the part we cooked the most. How evenly or unevenly creates the variance of flavor [as the cup moves from hot to cold, not the same thing as the number of flavors or “complexity” (whatever that means to you) of the flavors formed while roasting (that is a variable of the profile)]so more uneven the roast more variance in flavor as the cup cools, lower strength and lower duration of taste (because there is less material formed and this less to taste, but that is not 100% correct, just general). Char subsides, whether it reforms or changes back into flavor I have no idea, but letting the coffee rest so the char flavor subsides allows the other flavors to become unmasked. This can be part of the above equation where the overly charred part is just rested out and disappears and the spots in the bean that were ideally roasted are left, unmasked, ready to be tasted.

Tldr: the coldest part of the cup is the hottest(most developed) part of the roasted bean

Ps. Sorry for all the edits I had a LOT of coffee


#8

A video that I came across from Giesen Webinar - Reading Coffee Beans for Profiling with Willem Boot, Marcus Young, David Sutfin and Katie Cates

Willem is the only person I have heard thus far explain the “exothermic” part of coffee correctly, when he says it is the heat of the coffee bean that has gone exothermic. Bless you Willem, I will never spell your name wrong again.

There are several videos that go over roasting and air profiling which I guess the Boot has spurred me to elaborate that yes I think air roasters should almost always do the opposite advice from a drum roaster in regards to how to apply heat, ex. if a drum roaster says “x bean needs lots of heat in the beginning”. I would agree completely (usually) (almost always) but I tend to tune out when they start talking about how to do it with the drum roaster, how to apply the heat, is what I mean to do the opposite. So in the webinar when they talk about high pressure, I don’t think that applies to air roasters because our air does not build a lot of back pressure. If someone knows how much back pressure is built up in the system given an air fan %, I would greatly appreciate it (@anyone). I assume it doesn’t because building a back pressure would mean that there would be resistance to air flow (our heat source) and thus counter-intuitive, also bean loft increases, meaning that to me, the limiting factor is the weight of the beans, the shape of the beans and density, roaster’s airflow path, and the ability of the roaster to push air. These variables are creating the resistance that is in our roast equation. However the beans are overrun by airflow, there is just so much pulling the equation on the negative pressure side and not the positive pressure side. But everything is on a bell curve, or sliding scale. So air roasters APPLY heat differently but to the beans it should/could feel the same drum roaster or air roaster. So if you want to fry a dumpling you could do it with oil, or air but not with water (combi ovens excluded), how you work with the medium using different tools can overcome the same variables.

The dirty deeds:

  1. If I try and reach 500F in 1min, with a 100% fan or 60% fan, both take longer than 90-80% fan
  2. At the end of the roast, if I am using an 85% fan if the roast fails, it will most likely be baked. If I had a 60% fan it will most likely develop charred notes

I use the fan to maximize the heat applied by the profile. That’s why I say it is best to find the temp profile with a flat 80% fan first and then try different fan settings to minimize or maximize the ROR or specific segment (like a flat end of roast).

If something I say does not make sense (here or previously) please quote whatever part and ask and I can elaborate.


#9

Beginner tip for reroasting coffee:

So I have been ruining plenty of washed beans lately, my forte is usually dry processed beans, simply because I’ve just roasted more of them. Eventually after some more roasting xp I’ll have wet processed figured out, no problem Bob. But until then, I have been doing some reroasting trials and somethings are showing interesting notes . First, I should say I haven’t had an amazing result yet. So far just coffee that tastes fine with milk. So with a little more experience now, I like to shorten (squish) the profile so overall time isn’t too long and I like to put the heat much lower. Next time I think I’ll take the beans in the 440F-470F, 226C-243C much slower, to try and land the roast in that range.

Usually when experimenting profiles, my roasts tend to be underdeveloped rather than overdeveloped, like raw dough like flavor. I don’t drink too much of them if at all and will reroast them. Scott Rao always mentions how he’s not a fan of naturals and I always thought that was a curious thing. He would say it doesn’t agree with him and I would assume (rightly so at the time) that the processing method for dry processed coffee’s were dirtier (because of green defects) and it was just a sorting the green before roasting issue. But since I have had all these failed profiling trials lately, I’ve noticed this too and now chalk it up to the coffee not being developed, specifically that carbohydrate that tastes like raw dough, only because it gives me the same feeling when I drink it as I have had when I have tried half fried raw gooey dough (don’t ask how or why I have had that experience). It also fits quite neatly that air roasters do well with dry processed coffee (because of the density? Or processing?) and drum roasters do well with washed coffee…hmm :thinking:

Hope everyone is safe and well, eat your veggies and take care of yourselves out there.