8
●
Unscrew the single screw in the middle of the bearing (some are hex-head, some are Philips-
head).
●
Support the air pipe to prevent it from falling, as it is not firmly affixed.
●
Remove the front plate, then the drum.
To reinstall:
●
Take note of the drive slot on the drum and the drive pin on the drum motor axle. Slightly rotate
the drum while inserting it until the slot slides over the drive pin. When properly installed, the
entire drum, except for the axle, will be entirely within the roasting chamber, and the drum will
not
turn freely.
●
Insert one end of the air pipe over the flange on the rear control cabinet. Be careful that it does
not drop, as it is only a friction-fit.
●
Slide the front plate bearing over the drum axle. As the front plate moves into place, insert the
air tube’s forward end over the bean entrance chute’s flange.
●
Lightly reinstall the screws.
●
Ensure that everything is in place before tightening the screws; do not over-tighten.
Heater Replacement:
The factory has supplied slightly different heaters over the years. When
replacing defective heaters, while not essential on the 120-volt version, it is good practice to replace
them both. Replacing both heaters on the 220-volt version is more important. Two different heaters in
series will result in the voltage across them being different, possibly leading to early failure.
First, remove the front plate and the drum. Also, remove the cover from the electrical bay; it has a
small fan on it. The fan wires plug into a little white connector with a spring-release tab. Using a 5.5
mm socket, take the wires off of the four heater connections. Using a 7 mm socket, remove the bolts
from the defective heater(s). The heater(s) will come out easily. They connect to the roasting chamber
backplate only with those four bolts, passing through holes in the backplate and the rear compartment.
Roasting Guidelines
Since this publication is a handbook for Quest roasters, not instruction on the finer points of roasting
coffee, the following guidelines are not a complete description of the roasting process, which is as
much an art as science.
It is essential first to understand the process using only the senses. As the roast progresses, you will see
the beans change from green to yellow; this usually happens at a bean temperature of about 160°
Celsius. The smell will be like grass or drying hay and gradually smell like baking bread. You will also
see exhaust exiting the roaster at two intervals. The first one will be mostly steam, which will subside,
then you will see smoke. You will also hear two distinct sounds as the roast progresses. First-crack start
(1Cs) will occur at about 205º Celsius; it sounds like breaking pencils. At this point, the typical coffee
smell will begin to emerge. Second-crack start (2Cs) will occur about 225º Celsius; it sounds like
breaking toothpicks. The first crack and second crack periods last for about 10-15º Celsius, mainly
depending on the bean. It is good practice to know these points of roasting and to anticipate their
occurrence. The sections Roasting Guidelines and Profiles below contain suggestions for appropriate
timing, temperatures and settings.
