1st effort roasting on Huky 500T... advice?

Discuss roast levels and profiles for espresso, equipment for roasting coffee.

#1: Post by samhfoley »

I recently purchased a Huky 500T after having roasted in a popcorn popper for the past 12+ years. Having gone primarily by sight sound and smell I am a bit overwhelmed by the science involved with tracking and properly calibrating my roasts. I am using the stock IR heater, variac. Here is my roasting profile from 450g SM Liquid Amber for espresso. I tried one roast before this where I used the black dial to go between levels 1, 2, and 3. That seemed to work well. Then I read you were supposed to leave the black dial at 3(high) and change the heat only by blue dial, so that's what I tried this time.Tried to get steady 180 C for drop temp. shut off heat until TP. Then went full heat low/no air for about 3 min, then reduced heat a little and increased the fan to mid/low.

What is hard for me as seen here is there was no separation between BT AND ET for most of the roast. I had read that there should have been. It seemed a little long as well. I clicked first crack when the Artisan timer counted to zero but did not hear audible first crack until almost a minute later.

Again being a newbie I'm clueless as to what a lot of the measurements people are using for heat/airflow mean or how to read them.

Any help at all would be a godsend.

Other factors. Roasting indoors in a large warehouse with good ventilation. Jpn 100v electricity.

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#2: Post by Marcelnl »

roasting by sight and smell is also possible with Huky, it;s just that having some measurements makes controlling and repeating roasts easier.
I am not sure what you are roasting for but 180 as drop temp is well below first crack, your readouts appear way off or you are at temperatures far below what you need.

some starters:

get a 50mBar gas regulator, 450g batches are above the sweet spot for the Huky, I'' d recommend starting at 350-400g batches.
use fixed batch size

preheat the Huky for around 20-30 min at 1-1.5Kpa
I assume you have the solid drum (non perforated) so your charge temp should be as high as what I usually do (280-ish 'C) but well above where you start (I suspect you want to be closer to 220'C charge temp.
Soak with heat low and air off, open up gas to the max (esp at 450g) after 45-60sec, open the air shutter at around a minute or so, fan at a very low setting.
Your turning point should lie around 1 m 45 sec or so

Once the beans reach approx 130'C set air to low and leave it there.
Depending on bean type you start dialling back heat from around dry end onwards, I use 0.5 kPa steps, aiming for a steadily declining Rate of Rise (delta BT).
drop at around 215'C
LMWDP #483


#3: Post by samhfoley »

Thank you so much
when you or other members talk about 1-1.5Kpa, what does that mean and how can I measure that? Is that obtained by the regulator (50mBar gas regulator) you asked me to buy? or is that the black IR dial between 1 flame and 2 flame setting??....

Sorry I should have said charge was 180C, I know some call it charge and some drop. That was my start point. but like you said....probably too low by what you have said.

Can you send me a pic/link for that regulator. I see many...some with dials and some without.....

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#4: Post by Marcelnl »

the gas regulator is the thing that usually sits right next to the propane bottle and is only downregulating the high pressure in the bottle to a lower level your stove can use, the blue knob you mentioned is the one you turn to in or decrease heat, the dial on the side of the Huky stove tells you what gas pressure you have set.

pics came out a bit blurry, but still:

pressure gauge

heat valve

pressure regulator
LMWDP #483


#5: Post by samhfoley »

preheat the Huky for around 20-30 min at 1-1.5Kpa
I assume you have the solid drum (non perforated) so your charge temp should be as high as what I usually do (280-ish 'C) but well above where you start (I suspect you want to be closer to 220'C charge temp.

Thanks so much for the pics.

I roast in 2 batch sizes. 300g for single origin/French Press and 450g for espresso blend (Liquid Amber). Which charge temp should I use as a base for each. I know that all beans differ in their density and this can effect each roast....but as a start point for me to use for now, what temp would you recommend for each batch size?

The regulator looks like what came with the Huky. The gas company put another regulator on the tank that they supplied to us. I can ask them if it is 50mBar or not. So the gauge on the IR burner itself is where you are getting the readouts to measure 1-1.5Kpa.

**edit** I talked to the gas guy this morning and he did not know specifically that it was a 50mBar regulator or not, but he did say that it was identical to the one that came with the Huky from Taiwan. I was able to play around a bit with the blue nob and see the difference in Kpa. Should I leave the main dial on 1, 2, or 3 flame after ignition?

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#6: Post by Marcelnl »

your pressure gauge will tell you what regulator you have, simply crank it fully open and read off the KPa, if closer to 5 you have the right regulator, if it ends around 3-3.5KPA you probably havea 30mBar regulator (although I would think the regulator has a label indicating its rating)

It is hard to give ballpark numbers for a solid drum (is it?) Huky as I'm using the perforated drum which behaves different due to lower thermal mass and more convection.

Your charge temp IMO does not differ much with batch sizes so close to each other, the thermal mass of the Huky is likely so small that you regulate the roast with the application of heat.

Now to the HOW to regulate heat, that is simple. usin the blue knob you open and close a valve that regulated the amount of gas that is turned into heat. The dial tells you how much pressure, AKA how far you open the valve. More KPa means more gas is flowing (due to higher pressure) meaning more heat produced by the (quite capable) IR burner.

I preheat the empty Huky (as we speak) at 1.5KPA or so with air on minimal for 20-30 minutes, then dial back the gas to keep the flame barely lit coasting back to my target charge temp (in my case around 280'C, yours will likely be lower, others with a solid drum Huky may be able to give advice)
Once charge temp is reached I close the air valve (in the SS tube going to the fan) charge the batch, wait 30 sec or so and crank up the gas to 4.5KPa.

once the BT readout shows approx 130 'C it's time to start monitoring your delta BT readouts aiming for a steady declining curve, which is managed by decreasing heat in small steps.
from my curve ytou can see at what points in time I usually adjust air and heat (your mileage will vary with the solid drum).
LMWDP #483


#7: Post by samhfoley »


Here are the pics of my regulator and the data I found in it. Yes I have a solid drum. I have to check but I'm pretty sure when I fired up the heat at full it was only about 3.

I have to go out to the storage shed after work and try again. I finally got a decent sized propane tank today. I'll update when I check it.


Yes, if I open the propane nozzle all the way and turn the connector to open the IR gauge goes right to 5.0. When I ignite the stove (3 flame setting) and turn the heat up to high the gauge then reads about 2.0. I didn't leave the heat on for any prolonged period of time.

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#8: Post by Marcelnl »

can it be that is an adjustable regulator?

Just give that what appears a black knob a twist (probably counterclockwise and see if that changes the max pressure/flow.
Otherwise you need to find a 50mBar regulator or limit batch size.
LMWDP #483


#9: Post by samhfoley »

Now I am really confused, sorry. To achieve what you're talking about 1.5kPa I am using the propane regulator and not the blue dial to adjust?

I had thought it was just a simple turn to full on for the propane and then adjustments were going to be made with the blue dial on the IR stove.

I get 5.0 when I turn that black switch full on, like I said earlier, but when the flame is lit the gauge is reading around 2.0.


#10: Post by samhfoley »

Can't thank you enough for all of your continued help. You're the only one who has responded to my posts on 3 forums. I really appreciate you working through this with me.