Kaldi Wide 400 building and keeping momentum

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
jokershill
Posts: 7
Joined: 1 year ago

#1: Post by jokershill »

I am looking for some advice with my new Kaldi Wide 400 and how to start off with enough heat to avoid scorching, while also building and keeping momentum throughout the roast cycle. I did three roasts yesterday and all took considerably more effort in terms of trying to keep a gradually decreasing RoR, and am looking for tips and tricks from more experienced Kaldi owners. All three roasts were 300gr of Guatemalan SHB EP and I use a Gas One 3100pb (1lb propane tank) and the Kaldi chaff collector flow system.

For my first roast of the day, I spent 10+ minutes around 200c to 205c before dropping down to 195 in preparation for charging. Heat was on middle and air flow at 2. I am concerned my RoR never really gets high enough as it tops out at around 158c and then starts to immediately decrees which causes me to raise the air flow to 2.5. Conversely, this roast looks and smells awesome so far but this rolled right into 2nd crack and doubt will taste good. As you can see from my artisan chart, I am constantly adding heat and increasing air flow (I probably should have stopped doing that as I approached FC):



For my second roast I charged a little higher thinking it will help start with high momentum, but this just brought the TP up to 112c which I doubt it ideal. Again the maximum initial RoR tops out at around 158c and drops off quickly, causing me to try all kinds of adding heat and raising air flow. with an eventual close-stall at 8 minutes which required raising the heat, so I imagine this roast won't taste all that good at all:



On to the third roast, which so far seems to have been what I hope was the best, but I really was aggressive in adding heat early on to try and keep the RoR gradually decreasing. The charge was 203c but I was aiming for 205c but caught a down swing for that, but my TP was 110 which again I think maybe too high. This roast I waited until around 1.5 minutes or so and brought the heat up a step higher then before but still found my self increasing air flow (2.5) at around 2.5 minutes. I had to repeat this again at 5 minutes as again the RoR was starting to drop rapidly. At 6 minutes I was able to raise the air flow a bit (3.5) which I brought down around 7.5 minutes as FC was really active. I dropped at 22% development but didn't mark this, so Artisan auto-marked that at 9:50 minutes:



So my questions to Kaldi owners is to walk me through some of your successful roasts? I tried to baseline and compare to the official Kaldi 400 solid drum forced air youtube video, but I do not find my roaster behaves anywhere near what I see in the video. I preheat for at least 10 minutes before going through my first roast, but for all three roasts above, getting RoR initially high without a very high charge temp, and keeping momentum without constantly adding heat + air flow is giving me all kinds of inconsistent RoR.

One thing I am trying to do which I am wondering is ideal, is to find a heat setting to start and stick with for the roast, and adjust variables like air flow. I am curious if other Kaldi owners lower the heat after charge and give the beans 45 seconds or so to soak, and then reapply heat, and if so, would you classify the heat setting as being a high setting or normal. I am trying to replicate the results of the Kaldi youtube video, but somehow I cannot repeat the RoR decrease that shows in the video:
Perhaps my heat source is not good enough but seems to be of the kind highly recommended. I was hoping to hear tips and tricks from others on building and keep heat throughout the roast cycles.

Capuchin Monk
Posts: 1276
Joined: 15 years ago

#2: Post by Capuchin Monk »

Welcome to Kaldi Wide 400 club. I've been using it for over 4 years.
For 300g roast, Gas One burner should be sufficient. By the way, is this the burner you have?

Try the following.
1) Once it's at charge temp, you want to reduce the heat and vent to min and then charge.
2) At 1 minute into soak, turn up the gas to max on your Gas One (if the above link is correct) and increase the vent to 1 or 1.5 on your Kaldi Chaff collector and leave the vent level there for the rest of roast.
3) At dry end (around 4 - 5 minutes depending on bean type), turn down the gas tiny bit.
4) At first crack (ideally just before), turn down the gas little more.
5) If you want to roast beyond the end of first crack, turn down the gas little again at that phase.

See how that goes.
Also, take a look at this thread -> Kaldi Wide thermocouple mod

jokershill (original poster)
Posts: 7
Joined: 1 year ago

#3: Post by jokershill (original poster) »

Hey there, thanks for providing feedback, and I find it interesting the idea of providing that first temp soak aspect. The burner I have is similar, it is this one https://www.amazon.ca/dp/B09HN88V85?ps ... ct_details

So I am sure it will behave similar to the method you mention. I do have the burner working with a 1LB propane tank and am told the temp will be slightly lower then when the burner is using butane. Using your method where does your initial RoR temp top out at, and about when does that happen? I would love to see a roast chart example if you have any to share.

Do you find a common charge temp with turning point to watch for? I ask as my experience so far shows the TP is pretty high, perhaps because it is a small machine and the bean and air mass temperatures can rise fairly quickly.

Capuchin Monk
Posts: 1276
Joined: 15 years ago

#4: Post by Capuchin Monk »

jokershill wrote:The burner I have is similar, it is this one https://www.amazon.ca/dp/B09HN88V85?ps ... ct_details
That one has higher output so 3/4 up after 1 minute soak may work.
So I am sure it will behave similar to the method you mention. I do have the burner working with a 1LB propane tank and am told the temp will be slightly lower then when the burner is using butane. Using your method where does your initial RoR temp top out at, and about when does that happen? I would love to see a roast chart example if you have any to share.

Do you find a common charge temp with turning point to watch for? I ask as my experience so far shows the TP is pretty high, perhaps because it is a small machine and the bean and air mass temperatures can rise fairly quickly.
I posted my graph recently here (in Fahrenheit, burner is 10,000 BTU rated and open full after 1 minute of soak) -> Ethiopia Dry Process Yirga Cheffe Mengesha Farm Roasting Discussion

Capuchin Monk
Posts: 1276
Joined: 15 years ago

#5: Post by Capuchin Monk »

Here is a recent roast. Tastes good!

jokershill (original poster)
Posts: 7
Joined: 1 year ago

#6: Post by jokershill (original poster) »

Hey there Mr Capuchin Monk,

Quick question around air flow with the Kaldi chaff collector. Due to the placement of the air flow duct being at the top of the machine, do you find controlling bean mass temp using the air flow speeds is such that if you want to increase bean temp, you increase air flow, and inversely decreasing air flow speed lowers bean temp? I see a lot of online roast instructions call for the opposite and suggest increasing air flow to cool bean temp, and when I try to apply this to the Kaldi 400, it seems to have the opposite effect.

I just wanted to run this by you as I see others recommend making air flow changes, but not explicitly suggesting if that will raise or lower bean temp.

Capuchin Monk
Posts: 1276
Joined: 15 years ago

#7: Post by Capuchin Monk »

jokershill wrote:I see a lot of online roast instructions call for the opposite and suggest increasing air flow to cool bean temp, and when I try to apply this to the Kaldi 400, it seems to have the opposite effect.

I just wanted to run this by you as I see others recommend making air flow changes, but not explicitly suggesting if that will raise or lower bean temp.
Kaldi Wide 400 is a small roaster and doesn't need a lot of vent, especially that Kaldi chaff collector doubles as bean cooler which is designed to suck in a lot of air. Take a look at the following link. Lighter Trick & Roaster Size

jrham12
Posts: 272
Joined: 5 years ago

#8: Post by jrham12 »

Jay,

I don't have a Kaldi and by no means am a competent roaster, but keep in mind that the ROR curve in Artisan uses the secondary Y-axis on the right side of the chart. So your ROR is not peaking at 158 deg C; if you look at the right side of the chart, it is hitting a rate of change of about 16 degC/min (in your first chart). If you look at the chart that JS (Capuchin Monk) posted, his ROR peaks at about 32 degF/min which converts over to about 17.5 degC/min. So you're initial drop temp and initial ROR looks to be pretty spot on compared to his. Follow his advise on the temperature adjustments and I think you'll see an improvement!

I'm trying to learn my way through similar issues on my Quest M3s... It's electric though so it is a bit more sluggish to react to changes in the heat input. I need to get better at anticipating the heating needs to keep my ROR curve on a more steady decline without stalling the roast.

Good luck and we'll keep learning together!!! :)

Josh

jokershill (original poster)
Posts: 7
Joined: 1 year ago

#9: Post by jokershill (original poster) »

Well jrham12 and Mr Monk, I finally got the chance to run through a few more roasts last night and although I haven't cupped them yet, I learned a lot from your posts and think the sessions went well (or at least way better than before):




I did three roasts that largely followed the above trend, and although they will probably prove to a bit from perfect, I am sure they will be better than previous. I used the soak methodology whereby I lowered heat and exhaust to minimums for the first 1.5 minutes, then brought things up to higher levels then before, and decided to just trust in the process and let the roasts progress, before freaking out and making big changes.

One tip I have found with the Wide 400 and Kaldi Chaff collector setup, is that small fan speeds increments can have huge impact on BT and ET readings, and most often a difference between 1.5 and 1.75 can change a dropping temp, to a rising temp. Actually the change you can see at around 6.5 minutes is from changing the fan speed from 1.5 to 1.75. I was looking to level things, and just a slight change, took things moving in the wrong direction.

Capuchin Monk
Posts: 1276
Joined: 15 years ago

#10: Post by Capuchin Monk »

jokershill wrote:Actually the change you can see at around 6.5 minutes is from changing the fan speed from 1.5 to 1.75.
That graph looks much better.
Did the chaff collector do a good job and not much chaff in the bottom chaff collector drawer? If so, you may want to keep the exhaust fan speed at one spot after the soak and let it stay till the finish, say 1.5 spot in your case. Also, try reducing the heat little more just before the first crack.

At the bottom of the graph, it shows "500g". Was that the amount of beans put in?