Hi,
Maria suggested I pose this question to the list so here goes.
I recently purchased the Hearthware Precision Roaster after using the
earlier version for over a year. I would like to start using the time to
second crack as a benchmark for future trials since the new roaster makes
this easy to do but I don't know a lot about the theory of timing by
cracks. It seems that for many of my beans the second crack seems to
indicate the beginning of a full city roast but I don't know if that is
unique to each type of bean or a more general rule. I am looking for
general tips on where to stop the roast in relation to second crack as well
as specific timing suggestions for beans that Tom carries. This new roaster
seems to have a totally different roasting profile from the earlier one so
most of my old reliable times are now worthless. I could conduct endless
experiments myself but I thought I would see what the group mind has to say.
BTW, I generally prefer my roasts a little on the dark side if the flavor
holds up but I am also interested in full flavor with lots of body. I love
a good Viennese or French Roast also (depending on how you define French
Roast). But if you think some bean deserves a lighter roast I would be
happy to know about it.
Thanks.
Don Staricka

Don,
Your tastes may differ from mine, but any further than a few snaps into
second crack and I get unpleasant flavors. But if you consistently roast to
second crack, then use that first snap as a starting point for setting your
stopwatch. You cannot depend on a certain elapsed time from the start of the
roast. I keep complete records of each roast, recording inlet temperature
and estimated number of pops (first crack) every 10 seconds. I installed a
thermocouple probe just beneath the screen at the bottom of the roast
chamber. I do not own a HWP, but it should be easy enough to do the same.
I have found that measuring the bean temperature gives unreliable results
due to the hotter beans, cooler beans, and hot air alternately affecting the
tiny probe causing widely varying temp readings. Measuring the air above the
beans gives a steady reading but then you don't know how hot the beans might
be getting. So I settled on the inlet temp as the best indicator of roasting
conditions. My Melitta Aromaroast has a variable air control that I can
adjust to obtain a given inlet temp for the roast profile that I desire.
However, beans from different origins will react differently. Some coffees
may have more water content and others will have widely different sizes (the
Yemens in particular). So you will have to keep records of each roast until
you have enough experience to judge the desired end point. You should also
experiment with degree of roast for each coffee. A case in point is Sumatra
Mandheling. Right away you will assume this coffee needs a dark roast to
bring out the rich full body, and so did I. My first roast was about 10
snaps into second crack and gave a disappointing, flat, slight overroast
taste until the third day when it improved with ageing. The next 2 roasts
were city, with one of these stopped only 20 seconds after end of first
crack. These 2 roasts were more flavorful, sweeter, and much preferable than
the first.
A final suggestion for your new HWP is to vary the bean weight until your
profiles match with the old ones. To roast hotter, add more beans, and vice
versa. It should not take more than a few teaspoons of beans either way.
--
Ken Mary - Aromaroast - whirlyblade - French Press
----------
<Snip>
<Snip>