TomC wrote:If nothing else changed, then you're just picking up more radiant heat off the faceplate than you were before. Buried in the bean mass is buried in the bean mass. But radiant heat passes right thru the beans.

FWIW (and it's not worth much), I've pretty much always arrived at 1C near 380°F.

Same here. My bean mass TC usually hits 375-380 depending on the bean. My electric HotTop I turn up the fan at 375 and cut the heat to 50% to counter the carry over for the electric element. Otherwise I hit first so hard the roast will run away and shoot through first way to fast and roll into second a moment after first.

My main takeaway from my first week of roasting with this machine is that it has as much flexibility as you could ever want. You can punch the gas, drop the air and move really fast whenever you like, and then turn on a dime by punching up the airflow to shed a whole bunch of heat really quickly. The challenge, for me so far, is learning to make adjustments as needed without overcorrecting and going way too fast or way too slow.

[creative nickname] wrote:My main takeaway from my first week of roasting with this machine is that it has as much flexibility as you could ever want. You can punch the gas, drop the air and move really fast whenever you like, and then turn on a dime by punching up the airflow to shed a whole bunch of heat really quickly.

You can add even more flexibility by using the damper as well as the fan control. For instance if you have the damper set to half tray/half chamber and the fan to 50%, you're running around 25% air.

Also, remember that the TC in the exhaust manifold reads exhaust temp not environmental temp. While it won't reflect chamber temperatures with great accuracy, it will reflect temperature changes resulting from manipulation of airflow.

The challenge, for me so far, is learning to make adjustments as needed without overcorrecting and going way too fast or way too slow.

That's as much a matter of anticipation as learning the controls. For starters, arbitrarily define 300F as EOD and start of Ramp. So drag heat to get a 5min minimum drying period (I typically go 6min), and crank the heat to get a 3:30 to 4:00 Ramp.

Anticipate 1stCs by about 15F, and lower gas to about 1-1/2" - 1-3/4" and increase air to around 80%. That should take you through the end of exothermia and get you a roughly 6F - 9F RoR after the inflection. After that, ride the gas as you watch Development RoR like a hawk.

After about thirty or forty roasts you should be able to hit your interval targets within 15sec.

400g is near the high end of the sweet spot. Perhaps not as responsive as 350g, but considerably more agile than 500g, and at 400g, the TCs will give very consistent readings. A 400g charge and an average moisture loss will net you 12oz, damn near; i.e., a very convenient bag for your "customers."

Of course, you'll refine all of my recommendations as you become more familiar with the machine and develop your own profiles.

Finally, enjoy.

Rich

These are very helpful notes, Rich!

I'm hoping to eventually get good at working with smaller charges for home use, but 400g is indeed a great size for roasting gifts for friends and family. And until I get much better at fine tuning my adjustments, it is probably what I will stick with. At double the charge size that I used in my HG/BM, though, it definitely increases the pain of screwing up a batch!