- How to read my pump pressure? Use a blind filter, turn ON the pump a read pressure gauge?

- How about the gauge, is it reliable?

- If I want to adjust the pump, what are the step by step things to do?

- Does pump pressure have influence on taste when compare to dose/grind? Is it negligible ???

Thank you

A1. Yes and yes.
A2. Yes.
A3. See below for rotary pump instructions:

HB wrote:Assuming your machine's pump is like Procon rotary pumps, you should find a pressure adjusting screw similar to the one shown below:


From Procon exploded view; also see Adjusting espresso machine's rotary pump brew pressure?

Counter-clockwise = more water passes from outlet to inlet through the bypass valve = lower pressure. Clockwise = less water passes from outlet to inlet = higher pressure. Barring more specific instructions from the manufacturer, the inlet pressure should be regulated to approx. 2 bar.

PS: See Water pressure and the effect(s) it may have on rotary pump for more details and the FAQs and Favorites for related topics under Rotary Pumps.

A4. See below for my take on it.

HB wrote:Lower brew pressure increases your margin of error. I recommend adjusting it to around 9 bar. But don't take my word for it, try it yourself. To really get an idea of what's affected, bracket the results with a good delta between each set. For example, try the brew pressure at 7 bar, 9 bar, and 11 bar for a few days each and then narrow in on the one you prefer. Typically the lower pressure settings will channel less, but crema production will suffer and the taste may go flat. At higher pressures, crema production peaks, but the risk of channeling increases and the taste may go bitter/acrid.

Are most "HomeBarista" satisfied with pump pressure factory setting or it is common to adjust pressure?

Any ROCKET R58 owner adjusting the pump pressure?

thank you

Most rotary pumps setups have a bypass valve that is sensitive to inlet pressure; some have a "balanced" bypass valve that delivers approximately the same discharge pressure independent of inlet pressure. Since the brew pressure is typically dependent on the inlet pressure, the brew pressure of most espresso machines with rotary pumps must be adjusted once installed. On the other hand, the brew pressure setting of espresso machines that run from a reservoir might be correct out of the box, but again, that's more luck than planning.

I think most people experiment with pump pressure. Small changes can yield a big difference in mouthfeel, sweetness and body. Unfortunately every coffee behaves differently so while blend x may be wonderful at 7.8 bars every other coffee may be hollow and boring. Most of us use many different blends so you have to compromise and set on a pressure that works good for most but is not perfect for any.

Once you get to the point you can pull the same shot over and over, then you can play with making small changes in pump pressure and observing what kind of change it makes. Higher pressures bring out more body but will also extract more astringent compounds while lower pressures will yield a lighter body but with more sweetness. The trick is hitting the mid point for a balanced up.

reading answers on this post, I guess it need adjustment.

reasons:

1- most of the time, i can see channeling on naked PF (I'm using COMPAK K10!)

2- small grind adjustment impact the taste really fast.

NOTE: when pulling shot, gauge read 9.5 bars

Thank you

then you can play with making small changes in pump

to adjust pump, do I run pump with blind filter and adjust the screw with pump running until desired pressure?

9.5 should be fine while pulling shot. I make small adjustments at a time-then recheck with blind filter. No need to adjust while running. Make your change then test.

cannonfodder wrote:Most of us use many different blends so you have to compromise and set on a pressure that works good for most but is not perfect for any.

Or get a machine with pressure/flow profiling. Then it's easy to adjust for different blends (and roasts, grinds, etc).

From 9.5 Bars, I had adjust the pump to 8.5 Bars. (reading from the R58 machine gauge)

If the gauge is not accurate and my 9.5 Bars reading is actually 10 Bars, this might explain what I'm suspecting, pump delivering to much pressure!

I did a few drink today and I have notice it take more time for blonding. I can say there is a improvement in taste and I'm on the right way... I'm use to a ratio of 66 to 100% on most blend (at 9.5 Bars factory setting) when I see blonding. Now it look it will be posible to pull a shoot at 50% brewing ration pretty easily.

I had enough drink for now and will tell you more in the next days.

NOTE: I did not notice any reduction of crema lowering pump pressure