Controlling and understanding the water pressure in your coffee machine is important in order to successfully extract it. This parameter is completely controlled on automatic machines while it is less on a manual machine such as the Pavoni. Some knowledge can help to better understand and better control the water pressure when using the Pavoni machines. In my article, I will especially talk about the pressure exerted on the piston when you press the lever.
Water pressure in the boiler
Some models of the Pavoni are equipped with a manometer. This allows according to the pressure to estimate the water temperature. The documentation indicates that the boiler pressure must be between 0.6 and 1 bar. The water will be about 94 °c. I explain this much more precisely in the following articulation.
La Pavoni manometer. The manufacturer recommends carrying out the extraction in the green zone of the graduations.
Mesurer la pression de l’eau dans le piston d’une La Pavoni
The water pressure in the plunger has an important influence on coffee extraction. I became interested in the subject and found several methods to measure this pressure.
Method 1: Convert the force applied to the lever in bar
La première méSome models of the Pavoni are equipped with a manometer. This allows according to the pressure to estimate the water temperature. The documentation indicates that the boiler pressure must be between 0.6 and 1 bar. The water will be about 94 °c. I explain this much more precisely in the following articulation.
To know the force applied to the lever of the coffee machine, there is nothing simpler: just put the machine on a scale.
The mathematical formula to use is available here. However, to make reading easier, a user of the home-barista forum posted a chart.
On professional machines, it is recommended to extract the coffee with a pressure of 9 bar. According to the graph, on a Pavoni, to obtain this optimum pressure, a force of approximately 13.7 Kg must be applied to the lever.
You can do some testing and then estimate if you apply a comparable force on the lever during your checkouts.
Second method: Install a manometer on the piston
Another (more costly) method is to replace the piston to allow instantaneous measurement using a manometer. If you are interested in this method, you will find user feedback on the Internet. Personally I find the rendering pretty, but at $300, well too expensive. The kit can be bought here.
Third method: doing a DIY
I discovered by chance a method much more hardcore (but precise and less costly). Always on the Forum home-barista A user to pierce the piston to attach on the side a manometer. The rendering is a bit weird, but ergonomic (when you press the lever one is on the side of the machine then the manometer is well facing the user).
In conclusion, to properly master a coffee extraction with a coffee machine La Pavoni, you must remember the following things:
- The boiler pressure must be between 0.6 and 1 bar.
- Leave the machine on long enough for the machine to be hot (some talk about 20 minutes, but personally I leave it on for less time and I have good results).
- Grind his coffee, pack it…
- Open the steam valve for a few moments to let the fake steam escape
- Lift the lever to allow a little water to flow. This step allows you to heat the piston to the right temperature, remove the coffee residue from the previous extraction.
- Place the filter holder (if using a spout filter holder, it must be heated before, as is the cup).
- Lift the lever, do the prebrewing (I do 6 to 7 seconds of prebrewing)
- Lowering the lever by applying approximately 13.7 kg of force, extraction must be between 25 and 30 seconds (with prebrewing)
- Enjoy your coffee:)
Well worth a read. Got great insights and information from your blog. Thanks.
We purchased our machine about a month ago. The coffee tastes great but…
When we raise the handle it falls back down again, so absolutely no “pressure” or resistance.
Any ideas, anyone?
It has to come from coffee. If the coffee is too old, the water will pass without resistance. Also, it is necessary that the coffee is ground quite fine and in sufficient quantity. To give you an idea, I grind very fine 16 g of coffee per coffee. But often other people go up to 18g.
Really appreciate your thoughts. Our coffee is fresh and ground on an as-needed basis, to a fine grind.
Our issue is that the we have some resistance when raising the handle, none to hold it up, or when being lowered.
Do you think that this is because the machine is not working as it should?
Hi I have a brand new La pavoni Cellini Evolution and my boiler pressure gauge is Lower than 0.5 is that a normal thing? How do I raise it
no, it’s not normal. the pressure must be about 0.8 or 0.9 bar. I think your machine’s thermostat is out of order. the water is not hot enough to make coffee.
The pressure guage keeps going into red zone at speed so I turn off machine as am worried about the machine exploding. Is it dangerous to use. Also the water level in glass water level moving around rapidly with the pressure rising. Thank you