The following information is for users of the Portaspresso System to help unlock the system’s full potential. Consider this information as a starting point on your journey to espresso perfection. With practice and experimentation, there is no reason why you cannot make the most sensational coffee you have ever tasted.
Rosco Preparation
Measure out approximately 20 grams of coffee beans. This is about the same volume of a 50 ml shot glass or a slightly overfilled double shot filter basket. It is also a good idea to experiment with slightly more or less coffee to find out what works for you.
You now want to set the grind size on the Rosco. Due to the high quality grind, you can effectively use a large range of grind sizes for extraction through the Rossa. In general, the finer the grind, the higher the pressure, but with careful manipulation, you can obtain similar pressure and flow within a relatively broad range of grind settings. The difference is the taste, and this will vary between coffees and their overall conditions. For example, the same bag of coffee will respond differently from the first shot to the last, especially if a week or more has passed since it was opened. Again, the key is experimentation.
Remove the cap from the Rosco and fill with the measured beans then refit the cap. Set aside and prepare the Rossa.
Rossa Preparation
Remove the filter head and wipe the piston and seal area with a damp cloth. Of course it is already clean, but a quick wipe ensures any slight residue is removed. Fill inside the unit with water by pouring water into the vent holes on top of the press unit, then fully unwind the spindle. Towel dry the outside of the unit excluding the spindle then put aside. Take the filter head and remove the basket. Clean as necessary to remove any residue, and refit the basket.
It is necessary to lubricate the internals each time with water prior to use. Minimising friction and any resulting vibration or shaking is critical if you are trying to make great espresso even better. It is also unnecessary to remove the filter basket each time providing you clean it often enough. The accumulation of small things really does make a difference.
Grinding and Tamping with the Rosco
Take the filter head with basket fitted and preheat with warm water. Shake out any water and towel dry. It does not need to be perfectly dry, just enough to prevent water from entering the grinder. Fit the filter head into the Rosco then grind until all beans are through. Remove the filter head and you will notice that the turning action of the cutter combined with the narrow space has effectively pre-tamped the coffee. Complete the tamping and ensure that the puck is square.
Preheating the Rossa
The importance of preheating the press unit correctly cannot be overstated. Temperature control is arguably the most important aspect of extraction, and is the main reason why espresso from domestic machines is never perfect.
Ensure you have boiling water at hand. Invert the press unit and fill with boiling water to just above the basket seal. Hold for about 20 seconds then empty (usually into your cup to ensure it is also preheated) and refill. Hold for about another 5 seconds then empty and refill to about 1 cm below the top of the cylinder bore.
You can adjust the temperature for extraction by varying the 5 second period. A milk thermometer can be used to measure the temperature, but holding your finger on the semi-insulated brass area beneath the inverted device gives a surprisingly good indication of internal temperature.
One more thing to consider is whether or not you reboil the water during the waiting periods. You should generally do it the same way each time otherwise you will lose consistency. However, boiling just once is best when conditions are warm and when indoors, but maintaining water on the boil is best for consistency when in cold or windy conditions. Again, experimentation is the key.
Extraction with the Rossa
Timing and smoothness is the key to good extraction. If you work too slowly, you risk losing the optimum temperature. If you are too frantic, you risk shaking the device and disturbing the puck. You want to work quickly but smoothly.
Once the press unit is preheated and filled ready for extraction, immediately fit and tighten the filter head. Turn the device to the upright position and immediately start turning the crank handle. This is where the magic begins!
Basic Technique
Before experimenting with other variables, it is advisable to build proficiency with the basic technique as follows:
Turn the spindle in at a pace that enables you to hold the device steady. As pressure increases, slow your turning speed. Once the espresso stream emerges, watch the stream and control your turning speed at a pace that maintains a smooth and steady flow. Stop extraction once the desired volume is reached and immediately remove the device from above the cup.
You do not want residual drops in the shot because their extraction characteristics are different to the main flow, and can potentially affect taste. Also, don’t be concerned about pressure. The form and colour of the espresso flow gives a more accurate indication of what is going on, as does the taste.
Pre-infusion
Once you begin to develop a smooth and controlled technique, you can start to experiment with other variables. The first is pre-infusion time. In general, the oilier the coffee, the longer the pre-infusion. If your coffee is old or has been exposed to the elements, you need to get pressure onto the puck as quickly as possible, so minimal pre-infusion is the key. If you are stuck with dry coffee, filling the chamber to the top of the cylinder bore helps to minimise pre-infusion time. You will be surprised how good old coffee can taste. The taste is not as full, but it will be very smooth. Of course you don’t want to make a habit of using poor quality coffee, but it is inevitable that from time to time you will have no choice, especially when on vacation.
Quality coffee gives you significantly more options. Start by turning the spindle approximately half way down, until slight pressure is felt. Hold the device perfectly upright and pause for approximately 10 to 20 seconds then continue with normal extraction. Experiment with different pause times, even up to 30 or 40 seconds. You can also experiment with different pause pressures, such as turning the spindle in until moderate pressure is felt, then hold for the pre-infusion pause. The naked filter head lets you see precisely when and how the espresso emerges. Use a mirror placed at an angle to gain a clear view.
Pressure Build-up Profile
This is the relationship between speed and pressure build-up prior to the start of extraction. A good starting point is to begin with the slow technique. Turn the spindle from start to finish at the same speed as that used during the extraction phase. This is a slow and steady approach and works very well with exceptionally high quality coffee. Next try a high speed, but not so fast as to shake the device. Of course you need to slow as extraction begins. Also try a fast start with a gradual slowing as pressure increases. Another variation is a slow start then increase speed as pressure increases then slow as extraction begins. A variation of this last technique is to continue at speed until a full thick espresso stream is formed then slow to a controlled pace. Combining these pressure build-up techniques with the pre-infusion techniques is the key to unlocking a particular coffee’s full potential, and discovering the best combination is essential for espresso perfection.
The Extraction Phase
The main focus during the extraction phase is to maintain a smooth and steady espresso flow. The stream will wobble around a little when the Rossa is used freehand, but this is actually desirable because the slight movement of the stream tends to minimise disturbance in the cup. You will find that forming and maintaining a steady stream requires higher pressure at the beginning of extraction and a gradual decrease as the shot progresses. If you are aiming for perfection, subtle mid extraction pressure adjustments are often required due to unanticipated flow variations that occur inside the puck. These variations are felt through the crank arm and adjustments to this feedback become almost automatic as your technique improves. Experiment with variations for yourself, but be sure to take note of the stream form and colour as this is your main reference.
Summary
As a whole, the combination of available variables both before and during extraction makes the Rossa a truly unique device for anyone seeking the ultimate espresso experience. You can vary coffee grind size significantly more than with a conventional machine, and you can vary temperature, pre-infusion time, pressure build-up profile, pressure during extraction, and adjust for unanticipated variations during extraction. I hope this page has provided you with enough information and insight to start you on your journey to espresso perfection, and I also hope you experience the full potential of the Portaspresso Specialty Coffee System.