Water Flow vs. Water Pressure

May 27, 2020

Would you rather control your commercial espresso machine’s water flow or act on its water pressure? If you do not know yet, let’s see how variation on these parameters affects your cup of espresso.

There are two simple goals we want to achieve when making coffee: extracting the best aromas and repeatability. Extracting the perfect cup of espresso is not enough if we can’t replicate that same result.

To extract all potential positive aromas we need to act on pre-infusion, as it is the phase where water infuses the coffee cake, fills the extraction chamber, and extracts 80% of the aromas in the cup. So what we are looking for is the ideal extraction time and pre-infusion curve.

Regulating water flow means to adjust how many grams of water per second wet the coffee cake and fill the extraction chamber, giving you complete control over pre-infusion time, and allowing to create different coffee profiles by saving your water flow settings.

Controlling water pressure instead, means to act on the pump. Pressure builds gradually in the group head until water saturates the extraction chamber, as resistance increases. By acting on the pump, we are basically controlling the flow, but we can only manipulate pressure completely once the pre-infusion phase is almost over. This brings little difference in the final result and, most of all, makes it very difficult to replicate.

This is why in Dalla Corte we have chosen to develop a patented technology that would control water flow, the Digital Flow Regulator. Created in 2015 for one-group coffee machine Mina, and integrated on the upcoming multi-group espresso machine Zero, to give you, as usual, only the very best #zerolimits #makeitbetter 

Water Flow vs. Water Pressure