hairyco wrote:So I've done more research on the KL, and I had a few more questions regarding its use and interface.

From what I've gathered, is it true that you cannot preheat the chamber before charging the beans?
All the videos on youtube have shown people dropping beans in cold. This is very different from the bullet or the IKAWA.

Second, do users have any control over parameters such as heat and fan?
It seems as if people alter the roast curve on the KL software, import it onto the USB, and press play. After that, you manually press a button to mark 1st crack and 2nd crack.

For what I want, I would prefer to have some input and knowledge of the power settings and fan settings at each stage of the roast. Does the KL provide that manual control?

No preheating. It's supposed to help back-to-back-to-back-etc roast consistency if after each roast the cool down protocol brings you down to ambient temp which is where you start for the next roast.

As for the software, Studio, yes, full control for heat and fan. Add any number of points to your profile to define what bean temp you want at what time. Creating profiles is fairly simple. Fan is basically the same. Add points to define what rpm at what time you want. You can override the PID and modify the amount of power the heater is receiving as well.

There are 5 buttons below the screen, loosely termed 1 through 5 looking at them left to right. To log first crack it's button 5 then 3. I don't roast that dark so I'm not sure what they are but I think you can also log end of first crack and start of second crack. If you mis-enter one you can change it later in the software.

ducats wrote:No preheating. It's supposed to help back-to-back-to-back-etc roast consistency if after each roast the cool down protocol brings you down to ambient temp which is where you start for the next roast.

Is there any way to hack that to drop beans in while the chamber is hot? Doesn't the KL have import profiles from roasters like Ikawa? If you want to copy Ikawa profiles, that means you really can't copy it that well.

There is the option of importing an IKAWA pro recipe to the Kaffelogic Studio software.
Not certain how it works as I have never tried that.

As for being able to drop the beans into a hot roasting chamber I don't think this is easily possible - You may be able to create a profile with a power profile zone at the beginning, as it effectively turns of the roasters automatic controls.
I have not tried this, but in theory it would work - In KL this is the same style of hack we do when using smaller doses, that would otherwise trigger the heat runaway protection.

When that is said: Does it matter on an airbed?

The Ikawa home for one also moved away from this approach where you load the beans into a cold heating chamber.

I understand why you do this in a roaster with a big thermal mass and potentially kilo's of green beans where you want to ensure you do not wait for the drum to heat up. And not dumping the beans into a hot drum would also make back-to-back roasts impossible in a drum roaster as you would have to wait for the drum to cool.

In an airbed the thermal agility of the roaster will be so high that it is of diminishing returns? My KL goes from 0-100 degrees C in 54 seconds and reaches 150 degrees in 1:48 on the profile I use the most.
Just an example of the agility

Nicolai

Yeah, what nicolai said. Assuming you're used to charging hot, the first few times not doing it feel weird, nothing else, then you realize you don't need to because the KL's thermal agility is so great, and life is simpler as it's less workflow to not have to wait for roaster to reach charge temp.

IKAWA probe placement won't match up with KL and I doubt fan power is a 1:1 equivalent. But getting KL to hit DRY END and 1C at the same time as a IKAWA profile should not be much of a problem though I've never tried.

Having moved from an Ikawa Home 100 to a Pro 100 I do wonder what you're supposed to do on a Home. On the Pro, the roaster heats up and then waits for you to add the beans before continuing. On the home, it indicates preheat while it's warming up but doesn't pause for the beans as it switches to roast which always made me wonder if the correct answer was to add the beans at the end of preheat/beginning of roast.

I am far from an expert, but I think with the Ikawa Pro the thought is that you are doing back to back sample roasts and want to minimize time. For the home users are going to not going to be doing long periods of roasting so the preheat would not add additional value (and probably prevent less experienced home roasters from starting it and leaving unattended for a while).

Since the fluid bed roaster doesn't work like a drum roaster where beans are heated by the air and the chamber and retained heat of the drum, preheating on an Ikawa would have minimal impact on the roasting since the beans are roasted via the heating element and airflow provided by the fan and not the retained heat in the chamber.

I guess because of that feature, roasts on a Pro actually take longer than a similar roast on the Home.

Ira

I've been thinking about fan speed. Luca made posts discussing how altering fan speed influences the heat, agitation, and temp read-outs. Indulge me, just trying to think through how a roaster like this is applying heat to bean, in hopes of stumbling upon ideas to improve profiling.

3 things I think fan speed impacts: (a) agitation (b) heat (c) probe readings.

(a) the relation to agitation is obvious. Fan speed is the tool to adjust agitation and ensure the beans are moving. We all know, beans are denser/harder to agitate at start of roast, and less dense/easier to agitate at the end. So, keeping "agitation level" consistent over the course of a roast, is not the same as keeping fan level steady.

(b) heat. I think people who have used a freshroast, or have used poppers for a long time, will know from experience. That lowering fan and keeping burner steady can change temperatures a lot. Lowering the fan is a (if not the) primary way to increase heat on a freshroast. I wonder what this interaction implies for a PID set up like the KL. The PID will adjust the burner to reach the goal BT temp - I suspect the burner power level will vary significantly based on your fan setting.

(c) fan setting and the probe readings. See Luca's post- Kaffelogic for the USA is on Indiegogo). This is using Roest, but I think the principle applies here; people who have used poppers or freshroasts may know this sort of thing from experience.

'Know thy probe' seems even more important for the KL, given that (i) it is PID (roast control is heavily dependent on probe reading) and because (ii) the forced air 'complicates' probe readings. A quick illustration of (ii). The obvious: the probe is measuring some mix of hot air and bean surface. It isn't "the bean" and I think everyone appreciates that, in general, for all roasters. But, are the readings a reliable, consistent indicator of bean temperatures? As Luca suggests, we probably shouldn't assume so. It's measuring a mix of bean surface and air, and we are changing that mix when we change fan speeds, and generally changing the roasting environment, it seems. Since small differences during development phase can matter a lot, these might be more than just theoretical concerns.

This led me to wonder - might there be ways to minimize changes resulting from fan speed? Doing so could be helpful to get more reliable/consistent probe readings, and also just help isolate roast variables when dialing in roasts.

One thing is given - you have to set fan high enough to properly agitate at the beginning of the roast. What next? Two ideas: (i) keep fan constant. This should keep velocity of the hot air constant, which I imagine is a key variable for how much the air impacts temp readings. keeping fan constant is a recommendation I have seen professional roasters give newbies several times. But, we all know, this might send the beans flying into the chaff collector at the end. The beans expand, lose mass, lose density, fly around easier. So, perhaps (ii) profile fan to maintain a consistent agitation level. Velocity of the air will drop over course of the roast. But, perhaps, with a relatively stable agitation level, that mix of 'how much the probe is measuring air v.s. bean surface' would remain relatively stable. I have some thoughts on how that might be executed- e.g., marking levels in the roast chamber to indicate goals for where bean loft should be.

Wonder what you all think. Even if I'm way off, I suspect getting a handle on fan speed will be important for finding good ways to manage the development phase on the KL.

A lot to think about...

Stumbled onto this today Mostly deals with drums but Hoos does a nice job of also incorporating fluid bed. Of course with the KL we have only the one probe and the chaff collector is not see-through until the new one comes out but you can take the top lid off to peek but that's like the biggest trier ever and must do something to the roast chamber atmosphere. Slower fan seems to drive energy into the bean better and I think you can get lower 1C temps and I've heard lower MET tends to make a better roast but I haven't studied this extensively.

I'm getting close in my own journey to trying one of the popular KL community profiles, probably D-Raost v4. Back when Jen Apodaca was with Royal one of her standard IKAWA profiles had a v-shape fan profile, lowest in the mid, same on either end. Somewhere she explained the reasoning and I think I highlighted it but can't find it.


And as far as I can tell, beans have no chance of entering the chaff collector. They'd have to reach the very top and during cooldown when heat is at zero and the fan is the loudest I've ever heard it not a single bean from my 90g batches makes it even halfway up the chaff collector.

I've come to settle on the Raost profiles for most of my roasting. I've not used DRaost. I think it's an adaptation of the original Droast (profile from a different person) which is a popular profile that is well liked. Raost V4 is my go-to and has worked well for a variety of beans. I reduce the preheat for delicate beans and finish earlier. Anything from 213deg finish for a geisha to 219 for others. I managed to get in on the daterra masterpiece split here on HB and that was really good finishing at 215-7 depending on the balance I wanted between black tea and citrus. Ninety plus Kambera was also very good finishing 215-217. There is also a long slow version of raost as well which I use occasionally if the need arises. The creater of the profiles talks about his theory of a constant fan speed at FC as well as constant power zones. I should start adjusting fan speed more specifically for FC to test this but it's been good without this level of tinkering and I've been playing around a lot with rehydration so one thing at a time. I would say with raost that I have found it follows the profile better without the flat power zones....... Whether it tastes better or worse I don't know as I have not compared.