treston
New member
I have seen some commercial machines promoting "pulse brewing" as though it is advantageous to the coffee. It seems to me to simply be a cheap alternative to proper flow control.
Some machines have their water gravity fed to a sprayhead (rather than pumped or flow controlled), these machines always have the same head of pressure so when fully open they allow out say 3 litres in 60 seconds. They usually operate on 30 second cycles. So if you want 4 litres over 4 minutes, it will open 10 seconds and close for 20 seconds, allowing out 500ml in that 30sec cycle, so allowing 1 litre per minute, and 4 litres over the 4 minutes.
Now is there any advantage to the coffee by having this pulsing, or would a lowered continuous flow rate (1 litre per minute) result in a better coffee?
i.e. it seems to me that flow control would be the better (more expensive) option, and this pulsing is just a cheap way of regulating flow rate.
Some machines have their water gravity fed to a sprayhead (rather than pumped or flow controlled), these machines always have the same head of pressure so when fully open they allow out say 3 litres in 60 seconds. They usually operate on 30 second cycles. So if you want 4 litres over 4 minutes, it will open 10 seconds and close for 20 seconds, allowing out 500ml in that 30sec cycle, so allowing 1 litre per minute, and 4 litres over the 4 minutes.
Now is there any advantage to the coffee by having this pulsing, or would a lowered continuous flow rate (1 litre per minute) result in a better coffee?
i.e. it seems to me that flow control would be the better (more expensive) option, and this pulsing is just a cheap way of regulating flow rate.