Thread: Heat settings on Bosch Digital Heat Gun

Originally Posted by acroz

Hello all, I have been playing with a coretto for a few months with good results but just upgraded from a cheapy Skil ($29) heat gun to a Bosch professional digital model (2000w).

I tried a roast last night of 250g Guatemala, dropped it with the pan at ~80 degrees and set the heat gun at full fan and 630 degrees, ie, full power. I had first crack at 4 mins. By comparison my old gun would not have seen FC until 11-13mins doing the same things.

For other users of this gun, can anyone give me an idea of heat settings they are using?

My coretto is a Sunbeam bakehouse with the lid modified to accept the heat gun through the old vent and a chimney made of a bit of old rangehood flex up through the old sight glass port to carry the smoke and chaff away from me and the heat gun. Cant post a photo as haven't made enough posts on the site (lurker).

Cheers, Andrew

Morning Andrew, welcome to Coffee Snobs.

I use a similar Bosch heat gun, though mine is now over 10 years old.

Heat setting depend very much on the configuration of your Coretto.

I start all of my 750 gram roasts from cold, HG set around 500°C, always run the gun on medium blower speed, never use high, I aim for first crack approx 200° @ 14 minutes and second crack around or just before 225° @ around 19 minutes, this gives me a dark roast which I prefer.

A method of monitoring temperature is an enormous help, I use a digital multi meter with heat probe, seems most on this forum use the Heat Snob https://beanbay.coffeesnobs.com.au/V...re-data-logger connected to a PC, though I see they are sold out at the moment, I find the DMM option gives me all the control I require.

Here's a pic of my setup which may assist.
DSC_0277_669x1000.jpg

Hi Yelta,

thanks for the reply, I’m using a digital BBQ thermometer with a heat probe through the side into the lower part of the pan, ie into the beans to watch. With my old set up FC was always around 190-200degrees.

Strangely with the new heat gun the thermometer was reading about 140 degrees when RFC was well underway, so I think there may have been a malfunction there.

Set up is very similar, but I’m still using the lid of the bread machine.

Domestic thermometers are seldom accurate, the main thing is that they are consistent, consistency enables repeatable results, which of course is what we are after.

Hi,

My setup isn't quite as closed as Yelta's, but it's similar enough to do a loose comparison. (I lied, it actually is a little more closed).
I run about 420 to 440 max on high fan. I also incrementally raise the temp and control it for pretty much the whole roast. For me it's about maintaining a RoR at different stages of the roast.
I've run on medium fan and had to raise the gun temp to 500 plus roasting 550 grams. I didn't like the thought of really hot air being pushed at the beans slowly. I should try it again though, that's the fun of doing this stuff.

I get first crack at around 190 and drop my beans at around 206. Time wise, I'm struggling to remember how long they are. I think it's about 16 min to FC, and 19 and a half for finish.

Running your gun at 630 degs on full fan is very hot, so something doesn't sound right with your monitoring if you only had 140 showing. I'm guessing you were closer to 200 with a sky rocketing RoR.

Good luck with it.

By way of an update, I’ve been roasting columbia popayan in 330 gram batches. Using a cold drop with initial heat setting of 480 degrees on fan 2 up until RFC, when I’ve dropped to 350 degrees and then lowered again to about 250 after first and into second crack.

Im getting to a first crack at around 198 degrees on my BBQ monitor at about 11mins. Then what I believe is second crack at about 214 -216 degrees about 15 mins. I am not completely sure it’s second crack, experience might prove me wrong.

I was was roasting a light roast simply due to being a novice and not wanting to burn, however with this gun I’ve taken it further and have found a noticeable improvement in the results, with a good reduction in acidity.

Ill post a pic of my set up next for reference.