HomeRoast Digest


Topic: Hottop & Veriac (48 lines)
1) From: MichaelB
Brock,
IMO the hottop is not as amenable to voltage tweaking as other roasting
devices. It has a built-in profile (time and temperature) that it sticks to
by turning the heater and fan on and off to stay on track. When a variac is
used to increase voltage it may allow the machine to get to its designated
profile temp slightly faster and shut off the heater for a slightly longer
time. And when the voltage is lowered it may take more time for the heater
to reach profile temperature so it will stay on for a slightly longer time.
These effects may vary the overall roast times but certainly not in the
direct ways that poppers and freshroast machines can be controlled.
Another issue with the hottop for tweaking are the actual hottop readings. I
remember reading a report in alt dot coffee a while ago that the hottop time
function varies as the voltage varies. Increase the voltage and the clock
runs faster! So the very readings we use to measure our success are
doubtful.
So IMO, the only way to really control the hotttop reliably is to bypass the
built-in system and provide your own control. I believe Jeffrey Pawlan has
done that big time (and big $$$). And Scott H has also done that by adding
his own independent controls of heater and fan. They can both create their
own profiles - something we variac tweakers can't do. Variac tweaking in my
experience is unpredictable. The way I use the variac is to keep the voltage
constant throughout the cycle so my results are predictable and repeatable
from roast to roast. And they are.
The saving grace of all this is that the hottop produces wonderful results
as is. These built-in features produce the consistency and quality roast
after roast. I've been using it for almost two years and almost three
hundred roasts, and I'm delighted with the results. I've found favorable
comparisons in my very limited experience with other home roasters (Jerry,
Tara) and the occasional purchase of coffees roasted by the man himself.
Could it be better? Perhaps the new programmable upgrade that will be
available soon will allow us non engineers to finally get some profile
control. And if my roasts get better I will have to wind up in seventh
heaven (whatever that is?) because I'm already in heaven with my current
output.
Happy New Year!
On 12/30/06, Brock  wrote:
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MichaelB


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