wait a second "Unfortunately, your attempt to compensate for this with a long preinfusion is confusing matters and is probably the main reason for your having to exert considerable pressure on the pull."

i was thinking that a longer pre-infusion was making the pull easier, not harder? is that wrong?

Hi again!

About the grinder and grind/dose settings (but really about how to get a pull at the right temperature from your machine):

The Mazzer is a fine little grinder, which I will assume is in perfect working order and the burrs OK if you bought it from new and don't get through vast amounts of coffee.

It sounds like what you did originally was fine: it's standard advice to tell people to start with a "standard Italian dose" and then grind slightly coarser than whatever it takes to stall the machine.

From what has emerged in this thread, I suspect you may have been getting sour shots then because the machine wasn't at the right temperature (too cold), since you weren't bleeding off the false pressure (air pressure rather than steam pressure).

But there's also something else, which has to do with the difference between say a Pavoni Europiccola and your Pavoni Eurobar lever:

If you still get sour shots with the dose and grind set up as described above and bleeding off false pressure, try pulling a couple of blank shots first to heat up the group head thoroughly. Remember that on the Club, the grouphead (which is the same as the Europiccola and Professional) is not mounted on the boiler so it may well require this to come up to temperature. The grouphead should be uncomfortable to touch even briefly when you come to pull your shot, and your machine may always require a quick flush to do this for the first of any series of shots after it has been left standing or when it has first heated up in the day.

So: I'd advise starting from scratch again, like you did before, incorporating the bleeding of false pressure first and then if that doesn't work pulling one or two blank shots or "sink" shots through the machine (maybe using the purged grinds from your grinder if you are not a single-dosing person).

About preinfusion:

Preinfusion allows the grinds to absorb water largely undisturbed, which makes them swell and press up against one another, decreasing the spaces between them. It also uses the water from the tank to do this, leaving you with the full contents of the grouphead for your pull.

A shortish preinfusion can also feel a little hard to pull since it limits the water that can be infused to the contents of the grouphead (preinfusion allows the water to keep flowing from the water tank), meaning much of the water will have been absorbed by the coffee grinds, leaving less water in the grouphead to push through with the lever so you get a short short and quite strong resistance during the pull, but once you get beyond around 6 seconds (depending on a range of factors including the machine, pressure/temp. setting, beans, bean freshness, grind, basket size and dose) the grinds tend to swell and pack the filter basket, further increasing the resistance.

If your grind is not so coarse or your dose so low that you get drips from the portafilter after say 10 seconds (and from what you write you aren't), then there's a good chance your long preinfusion is making the pull harder, although also shifting the taste balance away from bright, as you desire. At least I suspect this is what is happening in your case. It certainly makes it more difficult to be sure what to recommend on grind and dose, which is what you want to concentrate on to obtain better shots.

If you experiment a little it will soon become clear, especially if you resist the temptation to change more than one factor at a time. For the time being, I urge you start again with the basics, concentrating only on getting the machine up to the right temperature.

And if you ever come to the UK for some mad reason, feel free to pop round. There's nothing like a hands-on session, even if on a different lever machine - to make some of this much clearer and above all to get the "feel" of what you need to do to get the shots you like.

hello,

i've been doing the dummy shot ever since i did get the machine.. only tried a couple times without, of course that didn't help matters.

i did get a home roaster, i bought a heartware precision from jeroen 'hv'. and i did get some excellent green beans to go with it. i also did get a single basket. i started at the basics again.

all this did improve my espresso, but there is still this same flaw. almost every single cup i made was a shock to the tongue, if you know what i mean. i will try to explain it in more detail: it's always acidic in a sharp way, not the refined and wonderful sourness you get from great espresso. there's some harshness, which might also be caused by bitterness, not sure about this as it seems more of an unpleasant feel than a taste.

on a basic setting, the cup is just too sour, not enjoyable, the crema way too light, about as light as sand. when i set the grinder finer so the pull becomes hard, the result gets better, but still a little too sour and harsh, rather blunt. the crema never get hazelnut, it isn't that reddish (and dark) it's more like a dark camel with brown touches at best, it seems, even at a very early stop on a tough pull, with undrinkable intense extract. maybe this could give you or others some clue?

btw. the amount of crema is usually fine though, about 10mm, very decent tenacity.

best,
gido.

i did a temperature check.

i pre-heated a glass with boiling water. dumped the water, pulled some water directly from the grouphead into the glass, put the thermometer in there to pre-heat it as well. dumped the water again, pulled new water and put the thermometer in again, all as fast as possible to avoid cooling down. the reading was 87.5 degrees celsius = 189.5 fahrenheit.

i just read in the article about 'the professional barista's handbook' that 'it is fair to say almost all professionals prefer temperatures in the range of 185°F-204°F.' correct me if i am wrong, but this isn't pointing towards a temperature flaw, or could it still be?

btw. i always keep the portafilter attached to the grouphead as much as possible, to avoid cooling down.

all the best,
gido.

Hi Gido,

the temp sounds OK and great to hear you have already been practising a good routine there. It's easy to affirm that temp is OK because you have given us a figure.

Not so elsewhere. I'm really trying to help here, not criticise, but that is the weight of the dose you are using at the moment and how many pulls are using per shot/what is your shot volume or weight? All this information would help us diagnose why things are still not to your satisfaction. Otherwise, without being there with you it will be almost impossible. And unfortunately you have introduced two new variables in to the mix: the type of beans and the roast settings you are using on your roaster. Actually, make that three, because you haven't let us know how long you are resting your beans for before pulling a shot. But air roasters do tend to produce a brighter taste profile.

You describe your crema colour in detail, but that can be influenced by many things: the grind, pressure and temperature of your shot, for example, but is essentially also a result of the type of beans you are using, and how they are roasted.

Repeating myself, I'd say you really need to try and get as many of these variables out of the way as you can. Get some middle of the road sweet beans from a reliable and very consistent roaster, like Union, who do several suitable Brazilians or blends. Start off with the all the basic settings, from the grind setting on your Mazzer through to the dose.

Pay a lot attention to getting an even distribution before you tamp (I suspect a lot of the problem may be here). Then let us know how it goes. With new changes being introduced at every post it's really very difficult for anyone to give you helpful advice. If you want to spend some money, get some digital scales that measure in 0.1g increments and maybe a bottomless portafilter. Those are the two tools that will most help you get better results. I suspect the fault is not in your machine.

Cheers

Mike

hi,

let me sum it up,

dose: varies heavy, i've tried it all. best results around 7 grams for a single shot, depending on the beans a bit. (i've noticed they vary in mass)

volume: i tried different things, mostly i get around 30ml (1 ounce) or just a little less for a single.

pulls: about 1 whole pull for a single, sometimes a little less. i have tried half a pull less, and i have tried half a pull more; no great results in these directions so far.

simply double these values for double shots, except that i have tried using less coffee for double shots, too. around 12 grams (dependent on the beans) seems the best. with my single shot basket, 6 grams is impossible, you can't tamp it properly because the coffee (when compressed) won't top the tapered bottom of this basket.

(please note, with the double basket, single shots where best between 6 and 7 grams. that was before i started making doubles, and then later trying singles again with the new single basket i did get. this amount won't fit in the pavoni single basket, the level of the coffee will be too low to tamp properly. 7 grams is the minimum, but sometimes this will still induce channeling through the sides, 7.5 grams is safe)

i weight every dose with my iweight i101 scale. it's a good quality scale, it measures in steps of 0.005 grams, and i know how to use it. for coffee, i am satisfied with a difference of less than 0.02 grams. so, 7.015 grams is counting as 7 grams. that's alright, no? i have weighted before and after tampering (the result after is usually very slightly less, usually about 0.005 till 0.0010 gram, sticking on the tamper, falling from the side, and such).

about the coffee and roaster, i have got a perfect example how to roast from hv, my espresso improved with his coffee and roaster, so i think this is not the problem. while things improved a bit, the flaw of harshness remained the same.

i first let the freshly home roasted beans de-gass for a few hours, then store them sealed off in the dark. the i start using them after three days (thus the fourth) and finish them in a day or two, maximum three.

i have tried many different types of coffee and they all had the same outcome, the same flaw of biting sharpness, harshness, that i have accounted to acidic stuff in the espresso (btw, i am not so sure about that anymore, i guess it would be good to know what molecules actually cause this problem). i tasted some of these exact same coffees as made by others, and they were fine. i think it can't be the coffee itself.

i've started 'grooming' the coffee in the basket with a little cake fork, very gently making it more level, without producing clumps. a bit like using a rake. it does not seem to matter very much. i already tried to get the coffee in as evenly as possibly directly from the grinder (a bit tricky with a mazzer, but i have developed a feeling for it; the harder you pull, the more to the left the coffee will be dropped)

i clean the machine after each shot. a pull to wash the coffee sticking to the grouphead away, the brush to the sides and behind of the grouphead to get the remains there away, then finish cleaning it with a cloth.

i do put the portafilter back on the grouphead after this, so it will get up to temperature.

did i cover everything here? let me know if i missed anything.

some additional points,

it seems that when i need to use a rather great amount of force, unless the machine really almost blocks completely, the espresso will often turn out better than with an easy or normal pull. a rather fine grind will almost always produce better espresso than a slightly coarse one. too fine will suffocate the machine, too coarse will taste awful and very sour, with very light crema.

i've tried temperature surfing today, keep everything the same but the number on the pressure stat. i've noticed that at 7.5 bar (with the machine turned off, it will heat up just below 8 bar) that the sharpness was significantly less, but the coffee tasted almost like drip coffee, not like espresso. a bit too sour (but not sharp) and rather watery, no body, hardly crema. then i tried the other way around, as high as possible. that was just above 9.5 bar. results, a lot of body, crema, much more bitterness and, unfortunately, that harsh sharpness again. so then i tried in the middle, 8.5 bar. it turned out, not as i hoped.. in fact it was a bit like the worst of both worlds.

best,
gido.

Hi Gido!

Looks like it's just the two of us in here

First off, congratulations on being so methodical and detailed in your posting. it allows me to make a few final suggestions that may be useful. It would still be useful to know what type of beans you are roasting and to what sort of a profile. Different beans can be more acidic than others, and it seems that this is the harsh taste you dislike.

My first suggestion would be to simply rest the beans for a few days longer than your current 2-3 days. This would mellow them out further.

My second suggestion would be to focus on your distribution and tamping. The reason I say this is your comment on the shot pulled at 0.75 bars (I assume, rather than 7.5). The fact that you got a very thin shot, suggests channeling, and possibly (also from your other comments) that you could take the grind just a tiny bit finer.

On the distribution front, you rightly comment on the Mazzer's tendency to throw to the left. This is generally a problem when the Mazzer is not used as intended, which is to say with a fullish doser set up to deliver a single dose when you pull the lever. In my experience, thwacking the doser and dosing out a scattering of grinds per thwack does not improve the distribution. if you are single-dosing a weighed dose, try setting the doser up so that it delivers at least a half dose when you pull round the filled quadrant below the bur chamber mouth (the one that fills first). Grind your dose through the grinder and then brush out the burr chamber mouth and maybe spin the burrs for a second or before brushing through again, so that all your dose is out. Then click the doser round without thwacking to deliver this filled doser chamber into your portafilter before emptying the remaining grinds without thwacking madly, brushing or whatever you prefer to clear the doser screws and adjuster nut etc of grinds.

The cake fork is likely to cause more harm than good, since it moves quite a large volume of grinds from one area of the filter basket to another. The WDT avoids this by using a dissecting needle.

Buying a bottomless portafilter wil help you diagnose your distribution. It is a very effective tool for improving one's barista skills.

You may also find it interesting to satisfy your curiosity by trying a typically creamy and mild, low-acidity bean, like a Monsooned malabar roasted by good artisan roaster such as those mentioned earlier.

I hope this helps.

May the coffee gods smile on you

Mike

Marshall wrote:Jeroen Vriesendorp ("HV" to his old alt.coffee friends) is an encyclopedia of all things coffee. His list of European roaster links might be a good place to start, since he keeps on top of the local coffee scene. http://home.planet.nl/~rjeroenv/links.html#8a1

I'm a little surprised, this looks like a list of all coffee roasters and shops that have web links (and that the author knows about) while I expected something more in terms of the thread 'our favourite roasters'. Dallmayr, Douwe Egberts? yes it is coffee but...