I tried my hand at roasting a Brazil again- first time since the homeroasting competition- and again had some charring and tipping despite a lower drop-in temperature and a lower ET (although less than before). It ended up being about a 17 minute roast. Anything longer, and I fear "baking" the beans.

The batch size was 8 oz. My guess is I could drop that to 6 oz and it would help, but I'd prefer not doing that if avoidable.

Any other suggestions on how to avoid this? Is this more common in cold weather because of the need for higher ETs? And if so, would insulating my Hottop help in this regard?

thanks,
Rama

On the Quest M3, insulation made about a 10F degree difference in the ET, i.e. I could get the same roast speed at a 10F lower ET.

But unless you are very pressed for time, what's the objection to deducing batch size? Nobody will ever hand out prizes to the home roaster who roasts the most coffee fastest (Maxwell House can do container loads in a few minutes, but they'll never get a prize for taste ).

Rama

I resisted the need to lower my batch mass for quite some time. I was using generally 225 gm of beans and the results were to my tastes pretty darn good. I took Max's suggestions about ideal HotTop profiles to heart after some back and forth questions on his threads and tried playing with 170 gm loads. Max was right! Roasts simply come out with better flavors in the cup and with more control over the roast profiles. The beans I now roast including Brazil and softer Indonesians have remarkably few detectable roast defects as per the photos posted in the recent highly informative photo review of roasting artifacts.

Try lower loads for a while and see if you get more control.

another_jim wrote:But unless you are very pressed for time, what's the objection to deducing batch size?

Laziness mostly. Doing 1/2lb roasts also means I don't end up with an odd amount of beans at the end of each bag (I like do buy many beans in 1lb quantities to try everything at least once.)

Okay, thanks guys. Guess there's no magic bullet. 6 oz batches it is.

150 grams gets you 3 roasts per pound.

Even smaller batch sizes?!

Seriously though, this gives me a good reason to start blending more.

I don't use a hottop, but if it works to go just a bit smaller than 6 ounces, 5.3 oz breaks a pound into thirds. That means you have to roast more frequently, but it makes breaking up bags easy. That's what I usually with a new bean where it's nice to have a few tries to figure things out.

rama wrote:I tried my hand at roasting a Brazil again- first time since the homeroasting competition- and again had some charring and tipping despite a lower drop-in temperature and a lower ET (although less than before). It ended up being about a 17 minute roast. Anything longer, and I fear "baking" the beans.

How much fan are you using & where? I eliminated most of my charring issues(didn't have tipping problems) by not using the fan at all after a short period during the drying phase. Normal drop in is 325*-350*F ET & typical turn around temp is 190*-202*BT. I'm using the same 227g load I've always used & getting what I consider to be very nice results. I'm also using a 22amp Variac to help speed up or slow down the roast as needed & finding it to be a very handy tool despite what I've read about the Hottop not needing it.

I've roasted 3 different Brazils for espresso recently, all with a 4 minute+ stretch & all ending in the 14 minute range. The only one I've sampled so far is the Moreninha Formosa Raisin M/L(Feb 09) which I took just into the beginning of 2C (FC+). After 6 days rest I am getting very creamy shots with nut & strong chocolate flavors.

I picked up a couple used drums recently & based on a suggestion from Ed (Farmroast) I'm going to try adding taller stirring fins. Hopefully these will lift the beans high enough that they fall through the hot air in the drum instead of just rolling on the surface. If successful this should help to reduce charring with larger (227g+) loads.

John,

the fan is completely off for the duration of the roast. It probably has some value in clearing out moist air and/or smoke during different stages, but given that I roast outdoors year round, its easier to keep a consistent profile by not introducing variable temperature fresh air.

I had another thought that's Hottop specific: what about replacing the perforated drum with a solid one? Maybe the cheapest/easiest way being using wire and heavy duty aluminum foil.

Wouldn't that help with more even heating, and prevent some of the charring without the need to shrink batch sizes (as much)?