Hello,

A head-scratcher of a La Pavoni problem. Any assistance would be lovely. Here's the deal: My coffee is too cold. It comes out undrinkably sour.

I'm pretty new at this espresso thing, but possessing an incurable masochistic streak and a desire to tinker with mechanical objects, I bought a Europiccola off of eBay. The machine arrived in pretty good shape. The seller said it had been bought by her grandmother, used a few times and stored in the attic, etc. etc. The usual story. Probably true.

When I first got the thing, I pulled a few blank shots and noted the distinct odor of rubber in the water and little black bits that didn't appear to be coffee suspended in it. Not good. I tried it with coffee and got a sour brew that was way too cold. There was a fair amount of crema. I figured the rubber smell meant some seals were failing, so I got a set and replaced everything except the gaskets connecting the sight glass tube to the boiler (I couldn't get my wrench in there) and the boiler-to-base and heating-element-to-boiler seals (I need a tamper-resistant Torx bit to get the base off--haven't found one yet). I followed the instructions at pavoniexpress.com.

The seal replacement went well, and the few random hissings and bubblings (particularly in the sight-glass tube) that I'd noticed before went away. But the espresso is still sour, still not hot enough.

I don't know where the problem is. Perhaps someone with a keener, more experienced eye can spot it.

Here are some details:

Machine: La Pavoni Europiccola, post millennium (one switch)
Coffee: stuff from a local roaster, pretty darn fresh
Grinder: Gaggia MDF; I've tried a few settings between 3 and 6.

When I turn on the machine, it takes about 10 minutes for the green light to go off. At that point, I can hear the water bubbling away in the boiler. There is some noise from the pressure-release valve, but there's no visible steam coming out of it, and the noise is not constant.

If I open the steam knob, I get a whistling gusher of steady, hot steam. I'm unable to make potable coffee, but I've at least made some great hot chocolate with the steam wand...

Technique: I've tried both the single and double filter basket. No discernible difference in temperature. I fill the machine to at least 3/4 full. I turn it on and wait for the green light to go out. I pull a blank shot with the portafilter and basket in place. I remove the portafilter and basket.

I fill the basket pretty well and tamp it down to about 1/4 inch below the rim. (Yes, I'm using the frustratingly small stock tamper.) I lock the portafilter in place and lift the handle. I can hear water coming into the group head. No coffee drips out when the handle is fully up, no matter how long I wait. (The manual suggested I'd start getting coffee after about 10 seconds.) As I push down on the lever, no coffee comes out until the lever is about halfway down. Then it starts coming. The resistance is not very great--I can push the lever with ease, but it certainly wouldn't go down if I didn't push. I don't have to lean on it or anything. Once the handle is all the way down, coffee continues to come out for a few more seconds. It usually starts pretty black and ends with a brown crema foam. The crema is OK--if I swirl the coffee around, it stays mostly put and coats the glass. The mouthfeel of the coffee is pretty thin, though. It is very sour; not terribly bitter.

The temperature of the coffee as it arrives in a pre-warmed cup is about 130 degrees F, measured by a digital probe thermometer.

If I leave the portafilter in place and pull another shot through the used grinds, the resulting temperature is around 160 degrees. If I take the filter out and just measure the temperature of the water as it leaves the grouphead, it is above 190 degrees, as best as I can tell.

But if I put new coffee in the basket and pull a shot, we're back down to 130 degrees, or maybe a bit more. It doesn't seem to help if I let the machine warm up longer, and the second and third shots aren't noticeable hotter than the first.

I'm truly puzzled.

Any thoughts?

Thanks.

First thought is :

As long as you go the extra mile to wait for the green light to go off and then release enough steam to make the light come back on. Then wait for it to come back to stable ( element not on)

If at this point you machine does not produce fill temp water out of the group head you are probably looking at one of two things:

1. A gunked up or mis-adjusted Pressurestat ( descaling might remedy) cheap to try any way.

or

2. A blown element - Yes - they can still heat water just not quickly or very hot- and if it is just starting to fail will struggle and can be quite noisy to boot.

So go to the hardware store and buy yourself a Torx bit - get the bottom cover off and prepare yourself to clean up the inside, adjust the PStat and install a new element gasket

OR

install the gasket with a new element after you clean up some..... Sorry.....

We are crossing our fingers for you!

when my light goes off, and even after I briefly bleed the steam wand to release "false pressure" (though I'm still not sure about that concept), my group head is still cool to the touch, and if I were to pull a shot at that point it too would be cool and sour.

after purging the steam wand and waiting for the light to go off, I then perform a series of six 80% pumps of the lever arm, stopping just short at the top of where the inlet hole would be uncovered by the piston and would let water flow through the shower screen.

this flushes the cold water that was dwelling in the group back into the boiler, dropping the temp of the boiler (and ergo the pressure in the boiler) and the heating element kicks back on. those pumps mentioned above also bring hot water into the group (i think), either way the group then warms pretty quickly to where you can't hold your finger on it.

I then perform one flush through the shower screen with portafilter in place of about two ounces. then I wait a couple minutes. then i remove the portafilter and grind/dose/tamp.

then i pull the shot, and it's hot, crema-laden, and darn good. if I pull a second shot shortly thereafter, i think it's even a little better, generally (well documented in europiccola-land), probably because things are a bit hotter at that point.

basically my whole routine is trying to get the group and the portafilter up to temp, balanced against my impatience to do so (probably why the second shot is better).

i bet those things would help immensely. if not, you may want to think about defective heating elements, etc. but i doubt that's the problem if you're getting good steam. i just don't think you're experienced enough yet at the dance of temperature management of the group--takes some time.

good luck, let us know what happens...

I'm going to go with pressurestat as well. I just had one fail and I got steam and temp but not enough. It was a slow enough failure for me not to notice but when I got the new one in I could really tell what I'd been missing.

Check the water temp coming out of the PF (just open the handle and let it run). Should be 185F or so. It doesn't sound like you're getting nearly that.

I've watched professionals bang out good shots on my machine all night long doing no more than you are. There's really not much more to making a shot beyond what you're doing. Check that pressurestat.

Thanks Greg, Derek & mayhew.

I will try all those suggestions (starting with the easiest--six 80% pumps!), then move on to the pressurestat. (I've already descaled with white vinegar; I suppose I could do it again with a specialized descaling agent...) Finding the tamper-resistant Torx bit here in Belgium could require some work, but I'll report back.

Question on the pressurestat issue: Do my symptoms suggest a broken pressurestat, or one that needs to be adjusted?

If broken, is it as simple as buying a new one and installing it? I see espressoparts.co.uk has them for 15 pounds, so not a bank-breaker. But of course I'd rather not buy something I don't need.

If adjustment, is there a guide for how to do this on a Europiccola? I see this (http://www.home-barista.com/levers/removing-base-and-adjusting-boiler-pressure-on-pavoni-t907.html) for a Pro, but that makes use of the Pro's pressure gauge to know when the stat is adjusted right. How might I do this on a gauge-less Europiccola?

I really appreciate the help--I'm lucky to be able to benefit from all your experience!

While I am no expert I think the 6 pumps have minimal effect. In fact, I wonder if simply waiting as long as the 6 pumps take would give the same result and the pumping just gives you something to do.

Take the bottom off of your machine and look at the p-stat. It should have a white paint line on the body and dial that line up. (search this forum for pressurestat or look at pavoniexpress.com) If they do line up then the odds are slim that it needs to be adjusted. If they don't, you might be in luck!

If it is broken, yes, it's as simple as installing a new one. I think you'll have the easiest time doing that by removing the base, so start looking for Torx bits BTW, the former head tech of Whole Latte Love has opened a repair shop here in town. He actually recommends vinegar for Pavoni's as an excellent descaling agent, as there's no aluminium in the machine to pit.

That's a great deal in a pressurestat. They're $65 in America.

It does occur to ask you what the room temp is like when you fire up your machine. I have noticed that my machine runs a bit cold on the mornings it's around freezing outside (which probably equates to 60F room temp in my kitchen).

I definitely get colder shots in that situation, despite the machine being in tip top shape.

Some more results and measurements:

Room temp is cool--about 63 to 64 F.

I tried the six-pump method. Here's what happened:

-Filled machine to nearly top of sight glass.
-Turned on to let heat up.
-Green light went out after about seven minutes.
-Bled "false pressure" by opening the steam wand. Bits of water then steam came out. Closed wand. Green light came back on.
-Green light went out. At this point the group is warm to the touch, not hot.
-I do the six 80% pumps. Group is now hot--can't hold my finger on for even a second. Green light comes back on.
-After a few seconds, green light goes out.
-With empty portafilter in, I run about 2oz water into preheated cups. Water temp is between 173 and 175 F.
-I remove PF and grind/dose/tamp
-I put filled PF back on. I notice green light comes on for a few seconds and goes off. In fact, green light has cycled on and off once or twice while I'm grinding.
-I wait a minute and lift handle all the way. After about 10 secs, I do get coffee flowing out. I bring handle down slowly--not a ton of resistance. As before, there is decent crema.
-Coffee temp is 134 to 138 F in a pre-warmed cup. Warmer than before, but not hot enough. Taste is still sour.

I repeat the above (starting from bleeding false pressure) for a second shot. Temp is better--about 142 to 145 in the cup. Still not hot enough, still sour.

Two more items:
-I am using the double filter basket.
-I have a European machine (230V).

My guess is that, at this point, I'm looking at a pressurestat or element problem. (If there's anything in my technique that could be causing the problem, or could be improved, I'm all ears...) My search for the Torx bit continues...

Thanks to all. I'll report back when I can get the base off.

Before you start buying tools and parts, have you tried grinding finer? A proper grind and tamp should give quite a bit of resistance for a proper pull (around 18kg if you have a bathroom scale handy). The reason I suggest it is because an underextracted shot will taste sour, as you are experiencing.

From your descriptions, it seems like everything is working fine. An easy way to test the pressurestat is to time how long it takes to steam 8 ounces of water to 165 degrees. Someone else on the site with a newer Pavoni can probably tell you if you are in the ballpark.

Just something else to try - good luck!

-Brad

Brad: I've tried going finer without much luck, but I'll try going finer still.

Re 18kg of pressure: Do you mean the pressure I apply to the handle when pulling, or the pressure I apply to the tamper when tamping?

Re timing the steam wand: What temperature should the water before I start steaming? This seems like a good and useful test if I have some comparison figures.

Thanks.