Re: Rossa rules!!
Thanks Paolo, more than happy to comment.
Before I answer the query, Id first like to clear up a few points.
After not being able to buy a decent portable machine (what I consider decent; individual differences are evident), I decided to make my own. The first thing I considered in relation to the design was what exactly does it take to make perfect espresso. I initially had no intention to sell the device, so I didnt care about cost. All I cared about was designing a device that made as close to perfect espresso as possible, with the least amount of moving parts, and would not break. After starring at a blank AutoCad screen for a while, I figured out that all I needed to do was design a device that pushed pressurised hot water through the coffee. Pretty simple, and that is exactly what every espresso machine is designed to do. Its just that some do it better than others. I designed the Rossa to fulfill the fundamental requirements necessary to make perfect espresso, but simplifying the design called for total manual control.
What this means is that the Rossa is designed to do everything the same as what any good espresso machine is designed to do, but as opposed to pressing a button, you need to do it manually, which is why it is quite significantly cheaper than any machine capable of producing comparable results.
The same rules apply equally to grind size, dosage, exaction volume, pressure, temperature, and any other variable that matters. In fact you should be able to produce almost identical results to any machine by replicating its profile. Small variations will exist due to differences in how the water contacts the puck and pump vibration frequency, but most people wouldnt notice any difference if the profile is replicated correctly.
So, for better or worse, the Rossas greatest feature is also its biggest weakness: manual control. It must be treated like the precision device that it is, and it is important to follow the instructions exactly until you become proficient in its operation. Those who make the effort will be rewarded with unbelievable coffee.
I trained the Merlo girls in Brisbane and Gold Coast to use the Rossa, and all obtained good extraction. Petite girls can certainly use it well, but the standard device needs to be bedded in sufficiently and prepared correctly, and the support stand should be used. I prepared the Rossa for the girls, so maybe its not a true indicator. Nonetheless, I offer an extra long handle as an accessory for the standard device, and when combined with the support stand, almost any able bodied person should be able to use it well.
For anyone wondering, the standard model was designed to produce what I consider the optimum pressure without needing to use a gauge. In my opinion, over-pressurisation kills the shot. The short handle makes it difficult to over-pressurise, yet relatively easy to produce the correct pressure; assuming that it is used correctly. The thread pitch produces about the correct flow rate with the natural speed that most people seem to turn the crank arm.
The Rossa HC is easy to use as it also has the long handle. It also has a coarser thread. This provides more control for profiling, but it can be difficult to determine pressure without the gauge fitted. Once you dial in the grind and the profile for a particular coffee, it is quite easy to replicate the profile without the gauge. The HC should be easy enough for most girls to use, but the standard Rossa with long handle provides the most leverage.
I have considered dropping the standard model and replacing it with the long handle design, but the standard design has some desirable attributes. Firstly, the shorter arm makes it more compact for travel. Secondly, during my initial experimentation with pressure profiling, I occasionally got muddled and lost my feel. Focusing too much on the gauge. Even though the shots looked visually good, they didnt taste so well. I found myself reverting back to the standard Rossa without gauge to regain my feel. This reaffirmed the merits of the standard design, but I want everyone to understand that variations are available to ensure that everyone who buys the device will be able to learn to use it well.
I hope the above answers some questions and clears up a few misconceptions. I look forward to the day when we can discuss the pointy end of espresso evolution: pressure profiling. Come on guys, catch up! Sometimes I feel like Robinson Crusoe
One last thing, Im curious about the lack of crema. If possible, please send me a graphical representation of your profile. Regardless of the coffee I use (all fresh roasted), crema fills the whole shot and then separates to about half and half, then slowly settles to about a third of the shot. If the graph is not possible, let me know what you change to improve results.
Originally posted by 51606E6D6E010 link=1326844778/14#14 date=1327051287
Before I answer the query, Id first like to clear up a few points.
After not being able to buy a decent portable machine (what I consider decent; individual differences are evident), I decided to make my own. The first thing I considered in relation to the design was what exactly does it take to make perfect espresso. I initially had no intention to sell the device, so I didnt care about cost. All I cared about was designing a device that made as close to perfect espresso as possible, with the least amount of moving parts, and would not break. After starring at a blank AutoCad screen for a while, I figured out that all I needed to do was design a device that pushed pressurised hot water through the coffee. Pretty simple, and that is exactly what every espresso machine is designed to do. Its just that some do it better than others. I designed the Rossa to fulfill the fundamental requirements necessary to make perfect espresso, but simplifying the design called for total manual control.
What this means is that the Rossa is designed to do everything the same as what any good espresso machine is designed to do, but as opposed to pressing a button, you need to do it manually, which is why it is quite significantly cheaper than any machine capable of producing comparable results.
The same rules apply equally to grind size, dosage, exaction volume, pressure, temperature, and any other variable that matters. In fact you should be able to produce almost identical results to any machine by replicating its profile. Small variations will exist due to differences in how the water contacts the puck and pump vibration frequency, but most people wouldnt notice any difference if the profile is replicated correctly.
So, for better or worse, the Rossas greatest feature is also its biggest weakness: manual control. It must be treated like the precision device that it is, and it is important to follow the instructions exactly until you become proficient in its operation. Those who make the effort will be rewarded with unbelievable coffee.
Originally posted by 6072626E67676464726F6E6372010 link=1326844778/13#13 date=1327045995
For anyone wondering, the standard model was designed to produce what I consider the optimum pressure without needing to use a gauge. In my opinion, over-pressurisation kills the shot. The short handle makes it difficult to over-pressurise, yet relatively easy to produce the correct pressure; assuming that it is used correctly. The thread pitch produces about the correct flow rate with the natural speed that most people seem to turn the crank arm.
The Rossa HC is easy to use as it also has the long handle. It also has a coarser thread. This provides more control for profiling, but it can be difficult to determine pressure without the gauge fitted. Once you dial in the grind and the profile for a particular coffee, it is quite easy to replicate the profile without the gauge. The HC should be easy enough for most girls to use, but the standard Rossa with long handle provides the most leverage.
I have considered dropping the standard model and replacing it with the long handle design, but the standard design has some desirable attributes. Firstly, the shorter arm makes it more compact for travel. Secondly, during my initial experimentation with pressure profiling, I occasionally got muddled and lost my feel. Focusing too much on the gauge. Even though the shots looked visually good, they didnt taste so well. I found myself reverting back to the standard Rossa without gauge to regain my feel. This reaffirmed the merits of the standard design, but I want everyone to understand that variations are available to ensure that everyone who buys the device will be able to learn to use it well.
I hope the above answers some questions and clears up a few misconceptions. I look forward to the day when we can discuss the pointy end of espresso evolution: pressure profiling. Come on guys, catch up! Sometimes I feel like Robinson Crusoe

Originally posted by 70414F4C4F200 link=1326844778/8#8 date=1327016106

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