900g Full Flame test

Just curious if anyone who is roasting 900-1000g charges and hitting 7:30 first crack is actually noticing a positive effect on flavor/aroma/taste…is it better? I really am not being snyde here just asking. I am getting ready to review the Morten video. I realize that this may not be answerable since the info above is just trying to get to the baseline “roast system” values.


1 Like

Hitting that time is more about confirming you have enough power for the given charge. In roasting actual, you’d be decreasing power before that.

In this specific case, his goal is a 9 minute first crack with 3 minutes of development time

His first power reduction stretches out the time to first crack, the second reduction stretches the development time

Thank you.


I just added a 120mm x 120mm x 25mm(thick) 12volt muffin fan to the PCB cover. It looks clean, but I haven’t tried it yet. The holes in the cover reduce the air flow from the fan quite a bit. If this proves out to be effective, I may go back and modify the PCB cover by making a cutout where the fan is.



~3.25 inches from the Table top to the bottom aof the fan

Here is a link to the fan that I bought from Amazon, the variable speed control is included (~$19.00 USD):

(I also posted this in the IGBT Sensor thread)


Oh I like that. Going to buy one. Going to see if it’s cheaper on prime day

Are you trying to get FC down to match his to increase the number of batches you can roast in a shorter period of time? If you are happy with your roasts at a longer interval of time to FC I wouldn’t worry about matching his time to FC. There are many theories for roasting techniques. No one is right for everyone or every bean. If you shorten the amount of time to FC, you’ll carry more momentum, potentially shortening your development time.

Nope. The 7:30 FC is the goal when doing the full flame test roast to see if the machine has enough power to do that particular charge weight.

1 Like

I tried pointing a lower flow (50cfm) USB powered 120mm fan directly at the IGBTs through the cover for my last test roast. Got 1430W continuous with the IGBT temps settling at about 73C.

It only pulled my FC time in from 8:45 to 8:22, but I got distracted and the fan was running at F1 for the first few minutes of the roast, so I probably wasn’t getting as much convective heating as I could have.

Should be enough data for me to start trying out the two-reduction profile. I might do one more full power batch at a lower charge weight to get some differential data too. Thanks for the inspiration and ideas @krame and @billc, it’s been a fun learning experience!


Here’s the fan I went with BTW. I plugged it into the port at the bottom of the control panel for the initial roast, but I also ordered a little USB battery from SparkFun so that the 200mA for the fan doesn’t have to come from the Bullet


Sooo I roasted 4 batches today without the IGBT1 going to yellow warning at all! 3 of those batches were 1kg that normally would all hit the yellow warning especially on a warm day like today (80F outside). This was all thanks to @krame for mentioning that Morton mentioned to him that the PCB can be cooled better with a fan pointing at the board from the right side of the roaster! All along I had the fan pointing at the left side of the Bullet! @billc mentioned improvements for him too so I had to try it today. Jack pot! Here’s my set up this morning with fan on right.

Bryan Cranston Mic Drop GIF

You and your MIMEs … no one here was using them until you came along :laughing:

Someone has to liven this place up


That was actually Aillio support. Morton proved that the roaster should have more power than I was getting. Which is what lead me to open a support ticket and go down this rabbit hole.


I just read the thread and I had the issue that the power will drop suddenly after 6-7 roasts.

Bought this little guy and it is rock steady ever since. Maximum speed on it and it cooling the PCB nicely.

This is a recent 900g roast I did:

It can reach 8 mins but I did a little 1min soak at the start.


Do you just run this fan off a USB port, such as on your laptop? I am worried about overheating here, since I often keep the space at 80 or 81 F to save money on AC.

1 Like

I use a dedicated usb port off the laptop for the fan OR if I am charging my phone through a usb port through a jack on the wall.

After reading this post I bought the same fan from Amazon. I tried my first 1kg full flame roast a couple of nights ago. Triggered Erc 0004 even with the fan running full speed pointed up on the right side of the PCB. This was an unusual roast that I would never do in production. I was just following Morten Munchow’s suggestion to try a full batch full flame roast to see what the roaster could do. That roast is here: Roast World - Cup, grade, and analyze your coffee roasts in depth

As with all my 500g roasts this roast had scorching as well.

Is this relevant to you?


1 Like

That roast is to check the power of the roaster… not make good roasts.

Try this at 900g.