The Rossa PG Brass Air Espresso (1.7 kg) is a premium portable device that offers the same features as the Rossa TR, but includes the addition of a pressure gauge. Operation of the Rossa PG can be as simple as the Rossa TR or as complicated as the user chooses in the pursuit of the perfect pressure profile for a particular coffee. The addition of the pressure gauge dramatically transforms the device into a very versatile instrument that is sure to satisfy even the most fanatical coffee enthusiast. In addition to this versatility, the Rossa PG remains a compact portable device.
The Rossa Air Espresso is an evolution of the Rossa Hand Espresso. The design incorporates the key principles of the hand espresso into a more user friendly device. Extraction pressure is generated from compressed air stored in a detachable cylinder via a precision valve specifically designed for the Rossa. The pneumatic pressure generation design makes the Rossa Air Espresso very simple to operate and a pleasure to use.
Extraction pressure is largely controlled by pressure stored in the air cylinder. For example, charging the cylinder to 14 bar typically produces 9 bar extraction (pressure reduction due to equalisation), and a 9 bar charge typically produces 6 bar extraction. Optimum extraction generally requires a gradual pressure decline during the extraction phase, and the Rossa Air Espresso’s cylinder has been designed with a volume that produces the decline automatically if not otherwise manipulated.
Note – Air cylinder generally requires charging for each shot but two shots can be produced with a single charge (1 x 9 bar extraction and 1 x 6 bar extraction using appropriate pressure profiles). Maximum charge pressure – 20 bar (300 psi)
The air cylinder is supplied with a filling adapter to suit a standard Schrader fitting (car tyre valve), which provides flexibility to choose between a variety of readily available pumps (not included) ranging from small bicycle shock pumps to high pressure bicycle floor pumps and the 12v electric pumps used to inflate car tyres. Pump selection is personal choice, and there are numerous low and high cost options available. For those not averse to manual pumping, a small bicycle shock pump is a great option, particularly when size and weight restrictions apply. The 12v electric pumps are perfect for those who prefer to avoid manual pumping, and some can be powered from a small rechargeable battery and are even small enough to fit in the kitchen draw.
Basic operation of the Rossa PG Air Espresso is very simple:
1. Charge air cylinder
2. Fit air cylinder to main body
3. Fill basket with ground coffee and tamp firmly
4. Preheat device and fill with boiling water
5. Fit filter head
6. Invert and open valve
Note – Optimum espresso quality requires regulation of valve opening speed to control the pressure ramp-up rate. The valve assembly and overall design of the device provides the user with excellent control to regulate both the pressure ramp-up and ramp-down rates to suit individual preference. The addition of a pressure gauge on the Rossa PG provides a very accurate visual reference to guide the pressure profile. Read more about pressure profiling
A fantastic addition to the Rossa Air Espresso is the Rossa Base. The base is multipurpose: 1) Support the Rossa when not in use, 2) support the inverted Rossa Air Espresso during preheating and fitting of filter head, and 3) catch and contain water remaining inside the device after extraction. In addition to these very handy functions, the base matches the Rossa’s design to ensure the aesthetics are as pleasing as the coffee.
If you seek a compact portable espresso option and/or wish to explore the largely unknown possibilities of variable pressure control, the Rossa PG Air Espresso is the perfect choice.
See the Rossa Air Espresso in Action