Barista Express extraction too fast

Beginner and pro baristas share tips and tricks.
bergerb

Postby bergerb » Nov 08, 2018, 6:16 am

Hello everyone,

I was hoping to post this a little bit later, but my last try to fix my espresso didn't work and now I need help :oops:

This text will be a little bit longer, so the short version is:
Too much coffee,
Too much pressure..

So my story begins about two years ago, as I found a thing called La Pavoni and I remembered that we had such a weird thing anywhere lying around.
So I started looking for this weird contraption and actually found this gorgeous espresso machine in our basement.

My first tries resulted in some terrible tasting, I dont think I can even call them espresso, cups of coffee.
So I learned more and more about espresso, started using fresh coffee, got a decent grinder (Eureka MCI Mignon), replaced my steam tip with a single hole one, ...
And then my espresso was actually drinkable, now I can produce very consistent shots with my La Pavoni.

And then I bought a Sage Barista Express because I wanted to have more consistency, and I thought this is the perfect opportunity to get good espresso in my office and I don't even have to buy a grinder, since the Barista Express has one built in.

And it was like learning again how espresso works. I got problems with a second shot, because I didn't dry the portafilter enough, so I got more resistance and my espresso got over extracted.

Another thing was adjusting the top burrs on the grinder to allow finer grounds, because I couldn't go any finer.

The thing I am currently working on is getting the recipe I use on my La Pavoni to work with the Barista Express.

On the La Pavoni I am using 10.5g of coffee, with a ratio of about 1:1.5 and a time of around 30 seconds. I have very dark beans and with some foam, it tastes sweet and absolutely not bitter.

Then I tried to match the recipe on my Barista Express, so around 16g in and aiming for around 25g in 30 seconds.

Firstly I thought the pressure gauge is just not right, but now I learned about rotary and vibration pumps and OPVs, and now I think my pressure is just too high.

Soo, I adjusted the OPV (turned it 2 times around, out, counter clockwise), got a little less pressure, It went from *red-line* to *green-line*. (image) Still too much, but as this dumb pressure gauge does not have any numbers, I can't even tell, how much it actually reads. But I am assuming the green line is on 13bar, which is way too much, I know. But I dont know how to fix it... I am assuming the middle of the "Espresso Range" should be 9 bar.
Image

I don't know if I should turn the OPV more, or get a portafilter pressure thingy, or overthink my recipe and just get a lighter roast... I don't want to give up yet.

The last thing that is weird: I do not get my 25g out. I get around 40g, which is a ratio of 1:2.5 and not my wanted 1:1.5. But the grinder is already struggling with my current setting and if I go much more finer, I think the burrs soon will start to touch..

Thanks for reading through this, I hope someone has any idea what is happening with my espresso :D

Just to make sure: The valve I adjusted:
Image

Best Regards
Benjamin

User avatar
slipchuck

Postby slipchuck » Nov 08, 2018, 9:17 am

You are experiencing what I found out: the grinder is the weak link. I had to buy a separate grinder which improved the espresso a lot


Randy
“There is nobody you can’t learn to like once you’ve heard their story.”

bergerb

Postby bergerb » Nov 08, 2018, 9:44 am

The weird thing is that I already got fine enough, but now it just does not want to work :roll:

I'll try to bring the Eureka MCI Mignon from my home

Benjamin

User avatar
spromance

Postby spromance » Nov 08, 2018, 10:13 am

bergerb wrote:The last thing that is weird: I do not get my 25g out. I get around 40g, which is a ratio of 1:2.5 and not my wanted 1:1.5. But the grinder is already struggling with my current setting and if I go much more finer, I think the burrs soon will start to touch..

To clarify, does this mean you are trying to increase the fineness of the grind in order to achieve a yield of 25g, but right now it's 'dispensing' 40g?

If that's your goal, that must mean you're hoping to let the double shot button run it's programmed volume through. It would be a lot easier to either:

1. start the pull with the double shot button, and then end the pull by clicking the button again (use a scale to know when you've hit 25g)...OR
2. reprogram the double shot button's volume so that it pulls closer to 25g when it runs the volume through (i.e. so you don't have to manually stop the shot).

Details on reprogramming are in the manual, but I believe it's as simple as Hit Program Button > Hit Double Shot Button to begin > Hit Double Shot Button to end > the machine saves that new volume as the default.

Point being: if you aren't monitoring your shot yield, and either manually stopping the shot to get your desired 25g, or reprogramming the machine to give you 25g out, you're barking up the wrong tree adjusting the OPV, and you'll never get it set low enough to achieve what you're hoping to achieve.

That's not to say the OPV shouldn't be adjusted from the factory...I've lowered mine far enough on my Infuser so that for my desired grind setting (and flow rate) it's in the middle of the 'espresso range' ...but that topic is a bit separate from what I think you're trying to achieve.

Figure out how to achieve your desired yield (25g). Either manual stopping or reprogramming the button's volume.
Use taste to guide your grind adjustments finer/coarser.
Then, if you're still unhappy with your results, begin to consider whether the pressure differences from the Express and your La Pavoni can be overcome (by continuing to lower your OPV)...or, if you just need to settle on pulling shots differently on each machine.

Hope that helps.

bergerb

Postby bergerb » Nov 08, 2018, 10:40 am

Hi,

I am monitoring the yield and also manually stopping the extraction, when I reach about 25 seconds. But if I stop at 25g, my extraction time is far too less -> I have to go finer and thats where my problem lies, the Barista Express Grinder seems to not want to go finer :D

I'll try another grinder, maybe that helps :roll:

I actually at some point got to the 25g, which brings up the question if my coffee now is old. But it got roasted about a week ago so idk..
And as I got the extraction right, it still tasted bitter, and the gauge showed a too high pressure, so I thought - OPV Adjustment.

How far do you think I can go with the OPV?

Benjamin

User avatar
spromance

Postby spromance » Nov 08, 2018, 1:09 pm

Ahhh, thanks, got it. I see now why your trying to lower brew pressure to compensate for the lack of headroom on the grinder, makes sense.

I'm pretty surprised though that a coffee as dark as you describe can't shatter finely enough on the finest grinder setting to choke the machine at a 16g dose. Have you tried dosing, tamping, then using the Breville razor to trim that dose, then weighed to see how much that is? I'm not doubting your abilities to dose, pull shots, etc, but if your coffee is only 7 days old, either:

a) perhaps you could try an even higher dose (I'd be curious if using the razor reduced your dose below 16g or if it still allows space for say an 18g dose)
b) the grinder is truly, really poor quality.

I'm not saying it couldn't be the grinder, but I'd assume even with its limitations, that dark roasts would be the most trouble-free (versus, say if you were trying to use a really light roast). If it truly is incapable, that's pretty sad for Express owners!

...Regarding your question on the OPV, I don't have anything too objective to offer, but I will say I've been able to lower mine far enough that I chose later to go tighten it a bit (to raise pressure, since I ended up thinking I had gone too low). The biggest priority is just making sure you don't adjust it so far that leaks could happen*. Otherwise, if you're up for it, it's probably worth playing around as much as you can till you find the 'sweeter/sweetest' spot.

*you're probably well aware already, but in my mind, as long as the black clip that slides off the threaded adjustment can fully reseat, and the tubing can slide on far enough to be zip-tied down, you should be fairly safe from leaks.

bergerb

Postby bergerb » Nov 08, 2018, 1:22 pm

That would be a side-effect (i think :)) yes, but I initially thought about it because the pressure gauge is showing too much pressure.

I'll check how much is supposed to go in with the razor tomorrow.

I always thought that light roasts are easier to brew, because they extract nicer flavors at higher ratios (like 1:2 or 1:3, which would be achieved with a coarser grind)?

Anyway, thanks a lot for your help :D

Benjamin

EDIT: tried the razor and it looks like I can put more in it :)

This is 16.13g
Image

But I am getting closer.. today I got about 30g with about the right pressure (needle was almost straight up).. the machine just stopped early (I think because the OPV is letting water escape and the machine thinks it already has dispensed 40g)

Deebo

Postby Deebo » Nov 10, 2018, 12:10 pm

I own this machine and am quite familiar with its capabilities. I was having a little trouble following the exact issue, but generally speaking, to pull a decent shot on this machine, my dose was 17-18g, a HARD tamp, then pushing the pressure into over-extracted range, which slowly falls back into the normal range as the shot develops... there's your $500 pressure profiling machine. I would generally have it dialed in so after that ramp up, it would hit right in between your two lines, then slowly fall back into the upper end of their "normal" range, which is quite wide.

I also recommend overriding the volumetrics and just stopping the shot when you reach your desired weight, if not doing so already.

I do agree that the grinder is the weak link, but you can get some decent shots out of it. The Sette would be a nice compliment to this machine if you ever do look to upgrade.
Think it, but don't overthink it...

bergerb

Postby bergerb » Nov 10, 2018, 4:35 pm

Does the pressure fall down a bit by itself? I have to say that it can't be much on my machine, it stays about the same pressure through the shot.

And I will try to put more coffee in and tamp a little harder :D

Benjamin

bergerb

Postby bergerb » Yesterday, 3:54 am

Today I got some very freshly roasted coffee and I got the ratio I wanted. 17 in, 25 out. The pressure is still too high, I tried screwing out the OPV some more, but ended up just turning it a half turn (so now I am at -2,5 turns), because it got pretty wiggly and I don't want it to leak.

The pressure now is in the "Espresso Range" - just below the green line.

My conclusion is that (at least on my machine) the OPV is simply not made for such low ratios

Btw @spromance: You can actually put the clip on the valve if you completely unscrew it, because the threads of the screw are smaller than the gear that holds the screw in place :D