Coffee Roasting at Home - 121104

We're getting a little low on coffee so time to roast a bit.  I did 3 100g batches today.

121104-4 Mex - Was trying out new chaff collector and not paying a lot of attention to the profile.  A couple of things of note:

New chaff collector works sort of OK but still allows some fine chaff to escape.  I'll see if I can find some finer screen on line.

Fine chaff that escaped screen.  Need finer screen.

Glass chimney cracked from high heat (~500F).  I replaced with a different chimney with a somewhat smaller base that doesn't touch the metal roasting chamber.

Cracked glass chimney.  Replaced with a chimney with a smaller base that does not touch the metal chamber.

Dropped a bit early as roast was just entering 2nd crack.  We'll try and see how we like a lighter roast.

121104-2 Mex - Watched this one closely varying the fan and switching heaters to extend the roast

121104-3 Harrar - Watched this one closely but let the roast run hot and fast

 I blended the beans from these last two roast for an espresso.

After these most recent roast I'm inclined to heat the roaster with both heaters, then turn off one and use the fan to control temperature.  I'm also uncertain of the temperature probe readings as I think it's in the hot air stream and measuring the air more than the beans.  I may try to position it a little better.

In a related matter I found that a scant 1/4 cup of roasted beans is 17g.  The new espresso machine takes roughly 14g for a double shot.  I also found that 1/2 cup of green is 100g, the current load for my roasting experiments.