Pulsating flow on Andreja Premium - Page 2

[DC]

hi dsc,

Dan's right, time to take a step back, put the gadgets away and come back to it tomorrow. The most likely problem is the human-side of the operation , as side-channeling is a distribution/coffee issue, water taking the 'easiest' path through the puck, as illustrated by your puck-holes. I think I know where you get your coffee from so freshness isn't an issue

try this for preparation. A finer grind as suggested above, drop the chopstick step, and simply "fluff-up" the grounds with your stirring device (you're the one with the cork-and-needles device aren't you?) ensuring that you distribute as much around the basket as the centre thus avoiding over-loading the centre with coffee. Finish distributing by NSEW swiping with the chopstick, leveling off the coffee at the edge of the basket.

Then just one level straight-down tamp, same force you're using now (changing tamp pressure is relatively unimportant) on a flat surface. If the tamp is skewed this will cause problems, so knock out the coffee and re-dose. No knocking, nutating, second-tamp or twist. You might try a flat tamper for comparison, I never liked using convex ones. That should be enough to nail the problem. The simpler the process, the fewer the number of problems can creep in.

Which coffee are you using, out of interest?

EDIT

Also, to avoid cross-posting this with TMC, I can understand your thinking behind a concave tamper to reduce side-channeling, but it's really not necessary. I've always thought that convex tampers were flawed in that they result in an unevenly dense coffee bed (biased towards the center), and I've never had really good results with them. That may be a personal thing though.

In any case, you can achieve perfect shots with a flat tamper, so the issue remains your distribution. I'm convinced that you can solve this without any fancy toys

[dsc]

Hi Dave,

yesterday and today I tried the following:

- no tamps at all, which as I said makes a mess in the basket, but otherwise works quite well

- tamping with a crater like distribution, meaning that before the tamp the coffee 'fits' the shape of the convex base. This means coffee in the centre shouldn't be compressed more than the sides.

- tamping with a 57mm flat base, using NSEW and basically moving the tamper around the surface to make sure the edges are sealed

I tried getting rid of the BBQ stick, going back to it, using WDT with my needle tool, not using it on some shots, doing Stockfleths, modified Stockfleths, tapping, no tapping.

Results: early blonding on ALL of them:| I mean every single, except maybe the no tamp ones (blonding started a bit later). When I knock out the puck it's way more darker on the edges than in the centre which clearly shows that coffee on the sides is more extracted.

Coffee: Monmouth espresso blend.

Will order some SO's from HasBean today and hopefully get them on Tuesday. Will report back if anything's changed.

Anyway, I'm getting more and more annoyed with all this and it's seems less like fun and more like hard work, trying to figure out what the hell is going on.

Cheers,
dsc.

[DC]

give the Premium Espresso Blend from HasBean a go, it's a very forgiving blend (at least in my hands) and it's one I always fall back on.

whereabouts in the UK are you?

[dsc]

Hi Dave,

I've tried it and unfortunately I had the same problems with it as with this Monmouth blend. Will see how it goes this time. For the time being I decided to descale my Andreja, so now the boiler is 'soaking' in lemon juice (as in full of it)

I'm living south of London in a small town called Leatherhead.

Cheers,
dsc.

[CafSuperCharged]

Tom,

The photo you showed without tamping - my experience with Andreja is I have to keep some headroom. At 14 grams, after extraction the coffee just touches the beginning of the rim in the basket (for the spring that holds it in place.)

Also, it shows turbulence. I have had this a few times in the beginning, but would not remember how to reproduce this. The bubble you call side channeling might be that, however I have those occasionally, even when I cannot trace side channeling in the pour nor the puck when I take it apart.

Your temperature may be on the high side, still. Consult with the roaster about their machine they use, I would guess at least that is what they do to verify the cupping test. I found one Dave Schomer blend (Dolce) to be extremely finicky, but managed to get consistently good shots with Andreja from it.
Try measuring temperature during flushing at the PF exit - depending on the coffee I may go as deep as 88C.

IIRC your boiler was set at 1 Bar average (heating cycle). So is mine. This reduces boiler temperature. My - intuitive since I do not have all those sophisticated instruments nor the time nor the need because the coffees are so good - notion is I now need to flush longer than before, but it may be a memory error as I changed coffees.

My remark about the 0980 versus Andreja Premium difference was triggered by your machine having the Quick Mill logo on the meter dial, mine not.
Quick Mill is an Italian company located in one of the villages bordering Milano. Nice people. Definitely know what they are doing.

I replaced my PF by La Marzocco and found it better (you need to replace the gasket around the shower screen by a thinner one), but went back to the original QM double basket in the LM PF.

My question would also be how much caffè you actually extract in the cup, as this should be 50ml maybe, not significantly more.

Very important to me would seem the dispersion over the shower screen is even. There is this distribution disc above it - it it properly fixed?

As Dave S' signature says: happiness is a warm puck - and it should be a nice dry one that holds together with an even coloration.

Regards
Peter
Netherlands
Europe

[DC]

dsc,

I was asking just to see if you were close enough for me to offer some practical help, but obviously not

[Elbasso]

dsc

I've taken the liberty to use your photo of the soggy puck to start a spin-off topic about under-dosing and "puck turbulence". Hope this is okay.

The other topic can be found here: http://www.home-barista.com/forums/can-puck-turbulence-be-avoided-when-under-dosing-t6866.html

Cheers,

Elbasso

[dsc]

Hi guys,

Peter -
I tried no tamping today again and got a quite solid puck, with show screen impression, something completely different to that puck shown on the photo. Still it was darker on the edges than in the centre and the stream went blond quite fast, so I'm still getting side channeling.

I can't quite measure the temps on the output of the PF as I don't have a spare TC I can use for that. I might try to get one from work, although I'm not sure if they have any.

Were did you get you LM PF? I would love to switch to one and convert my current PF to a naked. I know EP has LM PFs but they charge a lot for shipping to Europe, so it would be great to find those PF's on the old continent.

The dispersion disk is in place and gives even water flow. Sometimes when the shower screen is wet water forms a single stream in the middle, because of surface tension, but when I wipe it dry with a cloth and turn the pump again 5-6 streams form again.

Dave -

I thought you might be asking to check whether I'm somewhere near, but unfortunately I'm not:|

Elbasso -

that's fine, no worries.

Cheers,
dsc.

[JonS]

Tom,

I have, in the past, had my fair share of horrific extractions on E61 machines which I've unhappily endured for prolonged periods. Things are much better now, partly due to a better grinder (Macap MXK vs Mazzer Mini) but also due to some other paths of investigation:

Certainly, my experience is not as vast as many on here, but, I've had somewhat conflicting results with so-called "under-dosing" of baskets on E61 machines. Sometimes it's been OK, others, rubbish, to the extent that I don't do it any more.

No, I always overfill and then do the Schomer NSEW finger distribution these days. My grind is fine, and my tamp is very light, mainly just to level and setup the appropriate headspace, which I decide really on the basis of ensuring I clear the shower screen on lock-in, and not really any more. I figure there's room behind the shower screen for a water cushion to form, and also, I figure, given how the water distribution works from the screw in the E61 group, there's also plenty of potential for turbulent flow to develop given too much room.

As a result of this, I have mixed feelings about the Synesso ridgeless double from the recent TMC group buy (yes, I'm the same JonS). Lovely basket though it is, it seems huge ! I have a very similar La Cimbali (I think) double which holds about 18g using my dosing method, and although I haven't actually weighed the dose with the synesso, the two baskets seem very similar in size. As you have found, with a number of coffees, the taste can suffer at this kind of dose level. Additionally, such a thick puck can cause real headaches for some grinders and really expose flaws in the distribution (from my experience)

However, I am very much a big fan of using different doses for different coffees and have had some fantastic results with 13g doses of quite a few of late. When I want to use a smaller dose, I use a smaller basket. I have this tiny double basket that came with my commercial machine, and, using my method, it loads with ~13g. Unfortunately, I have no idea what sort it is, but at some point I think I will try and find some more smaller baskets. My current next size up from this is ~16g (from memory) with an Iberital basket or a Faema basket, I forget which. This small dose scenario is important to me because my current grinder (Macap MXK) seems to have a real sweet spot in the grind fineness that favours a smaller dose. Sometimes with a coffee I hit a 13g dose which extracts beautifully but gives a smaller volume in a lesser time, and moving up a basket size without adjusting the grind moves it closer to the ideal. But I usually stop there, although I accept some coffees may need an even bigger size.

So, in terms of how this relates to you, I would see if you can find a smaller basket (maybe Scott @ HD or AlexV on TMC ?). Smaller than the Synesso, and smaller than the one from your machine. And try dosing it with less headspace and tune the extraction for the best taste, not worrying too much about the numbers. You may end up with smaller volumes and shorter times depending on the coffee, but it's worth having a play.

Additionally, you may find that temperature is coming into play. I realised the other day that for a while I had been butchering Hasbean's Premium Espresso Blend by brewing it too hot. It's a relatively dark roast compared to what I've been normally doing with SOs roasted at home, and when brewed too hot it just seems to blond early compared with a lower temperature. The best shots I've had have been moussy and sweet and have poured well from lower temps, a complete contrast to what happens with the hotter shots.

Apologies for the long post. I feel your pain, and I hope any of this might help you out some !

Jon

EDIT: I forgot to say: Based on all the above, I reckon the concave tamper is probably fighting the symptoms rather than addressing the cause of extraction issues. Though I'm not trying to dissuade you from trying one !

[cannonfodder]

I had similar problems with my two group when I first got it. the fix, grind finer, dose a little less (14-15 grams in my case) and tamp light. When I say tamp lightly, I mean tamp lightly. I used two fingers. Just enough to settle the basket and make everything even. I also stopped tapping the portafilter between the first settling tamp and second compression tamp, I also gave up on the two tamps, I use one tamp. I also thump the portafilter on my tamping stand 3 times to settle the grounds in the basket before the tamp. That is a light downward thump using the weight of the portafilter. I hold it about an inch off the tamp stand and let it drop under its own weight. The idea is to settle the grounds on a below the rim dosed basket, not drive nails.

It sounds like a lot, so to summaries, grind finer, dose 14-15 grams, knock off the top of the mound with the back of your finger, three light thumps to let gravity settle the grounds, light tamp and brew. Readjust you grind if needed and repeat. I know you stated that the beans 'should be fresh' and they come from a local roaster, but could you define should be fresh? I assume the roaster puts a roast date on the bags, or do they use the big glass bean hoppers of death and scoop and weigh your coffee when you walk into the store?

[dsc]

Hi guys,

thanks for your posts, it's great to read all this and I still have hope it will get better soon:)

As for the basket, at the moment I dose 16.5g and tamp very lightly (the same as Dave, two fingers and that's it). It seems to fit the machine quite well, leaving enough space for the coffee to expand during the shot. I was experimenting with lower doses for quite a while and I always got a messy puck with a lot of holes in it. I wouldn't worry if it was only disturbed, not flat, but those holes show that I'm getting channeling.

As for the coffee I'm using now I got it from Monmouth and if I remember correctly it was roasted 3-4 days before I bought it. They have it in quite big (0.5m x 0.5m) containers degassing and it goes so fast there's no way they are keeping it even overnight.

Anyway new coffee (fresh, roasted today) should arrive tomorrow. Will update this topic with details as how it went.

Cheers,
dsc.

[Elbasso]

I can really, really, really recommend getting a bottomless PF. Or, as BobS says, chop your current one. I was 200% sure that my distribution was okay untill I started using a bottomless PF. It doesn't only give away the channels but also shows clearly when you're not exactly level in any direction. Speaking of which: did you check if your MACHINE is level?

Cheers,

Elbasso

[RegulatorJohnson]

it looks like its bubbling because the cone is touching the hole where the espresso needs to go out. no air can get in so the flow has to stop for a second for the air to go in so more espresso can come out.

the cone starts as drips form all over and the slow flow doesn't cover the hole in the PF.

the cone grows the flow increases and the sides of the cone touch the hole in the PF. this blocks the hole making it need to gulp air in to let espresso out.

the cone reduces the size the flow slows and moves to the left so it now doesn't come straight out of the hole like at the beginning of the shot.

jon

[dsc]

Hi again,

The machine is level, so uneven position of the machine cannot be the cause of the pulsating flow, but I believe Jon is right, which solves the whole problem. The flow does stop for a second when it becomes so big that it blocks the hole in the PF, which, as Jon stated is probably caused by not enough air. This is similar to a situation were you turn an open bottle completely upside down and the flow also stops and starts because it needs some air inside to keep flowing.

I got some new coffee yesterday (Kalosi Toraja), which was roasted on the 28th of April. It's currently 2 days old, so still fairly gassy, although fresh enough to eliminate any 'coffee not fresh enough that's why it's blonding' situations. So I tried doses of 14g and 14.5g, grinding to a double basket, tapping lightly downwards to settle the grounds and tamping very lightly. Result: starts nice as a single thin stream and than goes blond after only 7-10s. Examination of the puck shows channeling holes around the sides and when I knocked the puck out I could see the darker edges very clearly. I tried 3 shots today, one of them was quite good looking, although went blond after 15-17s. Did the other two and with the same dose and tamp force they were completely different, much faster, as if the coffee was lifted by the water and it was flowing underneath the cake, blonding almost instantly.

To sum it up: I have no idea what to do, it just seems there's no freaking way to pull a nice 25s espresso with this machine. Annoyed, pissed off and pretty much thinking of throwing this machine out the window.

Cheers,
dsc.

[JonS]

Tom, really, try and get yourself a smaller double basket so you can keep the dose small, but without the enlarged headspace that the more "standard" baskets will give, for the doses you are using. Irrespective of what ought to be possible with the scenarios you're trying, it's just not working with your exact setup.

If I had a spare basket, I'd lend it you, but I've only got the one I use full-time in preference to everything else.

Don't lose hope, I'm pretty sure you can get some good shots with balanced doses, but you might have to go round the houses a bit first.

Jon

[HB]

It's currently 2 days old, so still fairly gassy, although fresh enough to eliminate any 'coffee not fresh enough that's why it's blonding' situations.

Actually overly fresh coffee practically always goes blond more quickly and produces thinner espressos.

We have this experience on Fridays at Counter Culture's espresso lab. They have classes on Wednesday/Thursday, so usually we have "leftovers" that are rested. When there is no leftovers, we interlopers go begging to the roasters and consider ourselves lucky if the coffee has had one day of rest. The result is much as you describe: Thin, sharp, blonds quickly ("baking soda" is a common taste defect). The super fresh coffees are also very hard to dial in... the grind setting has to be perfect, distribution has to be perfect, or it's channel city.

[dsc]

Hello everyone,

today I had some spare time, so I decided to test out different doses, keeping the distribution pretty much the same. I also played with tamp force and stuck a 0.3mm wire in the gicleur to turn the flow a bit down, foolishly hoping it would reduce channeling. So here we go:

Dose: 14g
Tamp: <5kg (light, tamper pressed with two fingers)
Effect: disturbed puck and huge holes, side channeling + centre channeling as well. Sink shot.

Dose: 14g
Tamp: 30kg
Effect: definite side channeling, puck sort of rose up and huge holes around perimeter. Looks like the water went under the puck, giving a nasty 10s blond gusher.

Dose: 16g
Tamp: <5kg (light, tamper pressed with two fingers)
Effect: nicer puck, solid, still visible holes around the sides, blonding very visible, again a quite fast blond gusher.

Dose: 17g
Tamp: =~5kg (light, tamper pressed with more than two fingers)
Effect: shower screen imprint, STILL visible holes around the sides, blonding less visible, thinner stream.

With 17g and a light tamp it was quite hard to get the PF to lock in without disturbing it against the screen, but doable.

I know the coffee is still quite fresh, but I'm constantly getting visible side channeling, no matter what dose, tamp force etc. This is getting a bit ridiculous, seriously.

I will wait until the coffee is a week old and try again with those doses. I'm 95% sure I'm going to get side channeling anyway, so I guess 'coffee not fresh enough' is not the issue here (although I agree it may blond faster, but wouldn't give those damn holes).

Just to make this post a bit less depressing, I drilled a small hole in the PF to let air in when I pull a shot. This means I get no more pulsating shots. Thanks again Jon!:)

JonS: I'm currently trying to get a used PF with a shallow basket from Italy (a friend of mine is going), and I will convert it to an NPF. Still even with this deeper basket, putting taste aside, larger doses should work with no channeling

Cheers,
dsc.

[BobS]

Well, next dumb question from me - have you tried using the Major? Just to see if it makes
a difference in the channeling?

Bob

[DC]

sorry to ask a daft question so late in the discussion, but your tamper is a perfect fit for the basket isn't it?

[dsc]

Hi,

Bob -
I haven't tried my Mazzer yet as the burrs are dull and I'm waiting for a replacement. Still I'm sure the Macap is good enough to produce a high quality grind.

Dave -
Yes it's a perfect fit, leaving maybe 0.3-0.5mm of space. I have also tried using a 57mm tamper (flat) and it's pretty much the same or worse.

Today I wanted to finish off the rest of the Monmouth blend, so I prepared a shot, using 16g, tamping hard and not tapping at all. I choked the machine, so I turned the grinder to a coarser setting and tried again, getting a pretty nice shot. I was surprised to see almost no side channeling holes in the puck after the extraction. Who knows maybe I found a cause of all this trouble? Will try tomorrow with the fresh coffee.

Cheers,
dsc.