Just got an Expobar for Christmas as an upgrade from my gaggia New Baby that I've had for a couple years. I'm running a Baratza Preciso grinder, dosing 14g for a double with a 30lb tamp, beans are about 2wks post roast, and I'm getting 2oz in 29 seconds consistently. My problem is according to the brew pressure gauge I'm only getting 7 bar pressure and it's taking a long time for the espresso to start flowing. I don't have a bottomless portafilter yet for this machine so I don't have any more info yet on quality of the shot. I ran a back flush with the blank basket and got 10.5 bar pressure build up. Do I need adjust the brew pressure? Any help would be appreciated. Thanks.

I see no issue with times and grinds, how does it taste? If it seem bitter, I would boost the grounds 16-18 gr, I would get fresher beans. My espresso may take from 5-8 seconds before reaching the cup.

Taste was pretty balanced at 14g. I overdosed to 16g, it took 17 seconds to hit the cup and 39 seconds to 2.5 oz with minimal blonding at the end. The brew pressure indicator through the process displayed 6bar for most of the extraction then without removing the portafilter and letting the machine sit while I steamed milk the gauge ramped up to 9.5bar. Once I removed the portafilter it dropped back down to 1.5bar. Taste of the overdose was more bitter than the previous. I'm confused on why it doesn't ramp up to 9bar and stay there during extraction, could it really be the beans and grind? Thanks.

Toddo_san wrote:Taste was pretty balanced at 14g. I overdosed to 16g, it took 17 seconds to hit the cup and 39 seconds to 2.5 oz with minimal blonding at the end. The brew pressure indicator through the process displayed 6bar for most of the extraction...

You need to make the grinder setting coarser and raise the brew pressure. As a good starting point, you should adjust the brew pressure to around 9 bar against a blind basket. See How can I adjust the brew pressure of a vibe pump espresso machine? and Is it really necessary to adjust vibe pump brew pressure? and if you really are interested, I still don't get it: Why adjust the OPV?

Toddo_san wrote:...while I steamed milk the gauge ramped up to 9.5bar.

This point of confusion comes up a lot; I'll be lazy and copy/paste my previous reply:

HB wrote:The brew pressure gauge reading is relevant when the pump is running, but otherwise isn't useful. I elaborated on this point in Brew pressure rising during warm up:

As water heats, it expands; since a boiler/heat exchanger is a closed system, the pressure rises. It's nothing to worry about since the expansion valve opens to relieve pressure as required. The expansion valve is typically set to open around 12 bar for rotary pump espresso machines since they have their own bypass valve to regulate brew pressure. For vibratory pump espresso machines, the expansion valve (traditionally called an over-pressure valve in this context) is set to open at the desired maximum brew pressure, usually around 9 bar.

In a nutshell, the brew gauge reading should fall to 0 when you lift the lever and then rise to the pump's set point. When idle, the reading is the pressure in the heat exchanger due to water expansion.

I got the exact same set for Christmas this year. I also have similar issues.

I started with a 14 g dose and then increased it to 16 g dose with better results. When I start brewing I'm showing 2 bar which will ramp up to 9 bar and sit there, for the most part, through out the process. What I can't seem to figure out is why it takes 10-13 seconds for coffee to start flowing. Everything I've seen leads me to believe 7 seconds is normal. More coarse grind does not seem to make a difference on when the flow starts. It does make a difference pressure and quality of coffee stream (gusher)

With my current gind setting (I think 4C on my precisio) in my very amateur opinion looks about right once the flow starts. Nice color and crema. I just don't see any flow until about the 12 sec mark. I would like to get a 9 bar 30 second shot that starts the flow around 7 seconds

I am a new member to this forum. This is my first post but have been lurking on this forum for a long time. I have learned so much here. Thank you.

Jdk737 wrote: What I can't seem to figure out is why it takes 10-13 seconds for coffee to start flowing. Everything I've seen leads me to believe 7 seconds is normal.

That seems in a normal range for shot flow start for a vibe pump that has to come up to pressure paired with E61 preinfusion chamber. Rotary pumps come up to full pressure almost instantly and hence flow starts faster.

It seems my machine might not be getting up to temp. After a long idle I flush I get the same water shower from the group as I do after a 30 second idle. No steam, no big drain out the back either. I don't have an Eric's thermometer, but I ran the flush following a 5 minute idle into a double wall glass cup and measured only 165 deg. Shouldn't it be closer to 200? I then pulled a double after a 5 minute idle with no flush and measured only 150 deg in the cup. Extraction took 30 seconds from lever up to lever down. Thoughts?

Also, used newer beans roasted on the 18th. 16.2 g and about the same 30lb tamp.

Shots all tasted sour so I tried dialing the grind and dose further. After running through nearly a bag of coffee I tried a 19 g dose with a finer grind (3A on Preciso) and the pressure finally hit 9bar then dropped to 8 bar through extraction. Took 50 seconds from lever up to lever down, and 36 seconds from start of flow until 2 oz (stopped based on blonding). 5 minute idle with no HX flush. Still only 160 deg in the cup and STILL tasted sour. It seems to me from what I've read this should have been really bitter.

Going to return the Office Lever. It must be defective as I'm even getting 180 deg in the cup on my Gaggia New Baby.