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4.3. Start Up: grouphead
The Vibiemme Domobar is manual in its function with only one switch controlled by a lever on the
grouphead itself.
Grouphead
. It is shown in its at-rest position. This is where the lever should be
whenever the machine is not brewing espresso.
When the lever is lifted just past the first click stop, the passive pre-infusion begins. This allows a slight
flow of water onto the coffee. This gentle flow of water wets the puck slightly, which helps with extraction
and can also help eliminate channeling (disruption of the coffee causing a fast flow). It is not necessary to
use this position, but leaving it in this mode for about two or three seconds can be useful.
Lifting the
Manual Control Lever
to its full up position opens the brewing path between the boiler and
the coffee. At the same time, the cam to which the lever is attached depresses the switch on the front of
the Vibiemme (just to the right of the E-61 grouphead, behind the cam). This switch activates the pump.
When you choose to end the brewing cycle, return the
Manual Control Lever
to its at-rest, fully down
position. Moving the
Manual Control Lever
to this position turns off the pump closing the brewing
path opening discharge valve which is built into the grouphead.
This is a path from the grouphead down through the lower portion of the casting, and into the drip tray.
When opened, it allows the pressure remaining in the brewing path to flow into the drip tray. This allows
you to immediately remove the
Portafilter
without worrying about the “portafilter sneeze”- a spurt of
coffee or hot water from confined pressure as can happen on lesser machines without a 3-way valve.
4.4. Start up: brew pressure gauge
The
Brew gauge
(scale 0 to 16 bar) displays the pressure in the brewing path during an espresso pull.
This gives a general indication as to what is happening during the brewing cycle. The only time when the
gauge will display any useful information is when the brewing process is underway. At all other times,
even when the pump is refilling the boiler, this gauge is not displaying any useful information and should
be ignored. About 9 BAR is a good place to be brewing as you get started. Each division is .5 BAR.
Important: the brew pressure gauge displays useful details only during the brew cycle, giving no further
information about brewing temperature. The only way to know brewing temperature is to measure water
coming our of the group through a thermometer ( even a digital one) sold by your retailer.
5. First use of machine
For this first use of the Vibiemme Domobar, once the pressure is above about 0.5 you should flush the
boiler to be sure that the machine is working properly. Place a suitable container (like a heat-resistant
glass measuring cup or stainless steel steaming pitcher) under the hot water spout and carefully open
the hot water valve. Water should pour out and the pump should start. Pump out about 6 ounces and
then close the hot water valve. Repeat this two or three times over the next five or ten minutes, and then
check the reservoir level.
WARNING: The water dispensed as described above is hot enough to cause serious burns. Use
caution whenever dispensing or disposing water.
After an additional five or ten minutes of warm-up time, test the steam function. Place a vessel under the
steam wand and slowly open the
Steam Valve
. Steam should come from the
Steam Wand
and the
boiler pressure should drop slightly. After a few seconds, close the
Steam Valve
. It is normal for some
water to spurt out of the
Steam/Water Wand
when the
Steam Valve
is first opened after it has been
closed for some time.
WARNING: Steam can easily cause deep and nasty burns. The metal
Steam Wand
gets very hot.
Always move the
Steam Wand
by holding the rubber sleeve and take great care whenever using
the steam function.
When using the
Steam Wand
, the pump may occasionally operate on its own. The steam comes off the
top of the main boiler where it is “stored” all the time, and the pump will only run when the water level
drops to a point determined by the depth of the water-level sensing wire.
Now it’s time to wait!
We mentioned in the other manual that patience is a virtue when it comes to making espresso and here
is our first example. The boiler, that huge brass grouphead, the portafilter, and all the related metal parts
need to come up to temperature. As the boiler comes up to temperature, hot water will circulate through
the system, helping to speed things up, but plan on waiting about twenty or thirty minutes before the
machine is ready for use.
