so whats your idea on whats wrong here?

[dsc]

Hello everyone,

Recently Ive been having massive MDF grinder problems and couldnt grind fine enough for espresso. Finally I realised that the play on the thread of the upper burr carrier is the reason. Ive added the two pushers under the carrier that make the stepped regulation mechanism and without the play it all seems to work pretty well.

Anyway I made a short video of how my extraction looks like on the "repaired" grinder:

http://video.google.com/videoplay?docid=8416375597710299418

It seems to start well, slow drips, pretty even pour comming from the whole basket surface, rather than from the sides of the center. Its starts to flow with a thin tail. After a few seconds the cone gets a bit bigger, but still looks pretty good. But at around the 20s the cone gets smaller and it all starts to blond, do you have any ideas whats going on? I switch it off at this moment and the whole extraction took only around 20s. Some info to help you:

Machine: Gaggia Classic
Pressure: around 8,5 bar
Dose: 18,5g
Dose method: split dose, double tamp with 20kg, NFSW on the second one and polished
Distribution method: WDT with a home made tool
Puck after extraction: solid, knocks out of the PF in one piece, shower impression on top
Coffee: 10 days old Bali God Mountain (100% arabica)

I appreciate any ideas So all you Sherlocks out there, go, go, go!!

Cheers,
dsc.

[Curmudgeon]

Re: so whats your idea on whats wrong here?

The "rules" of espresso are only a guide. And they do give some latitude, for example that the pour can take somewhere between 18 to 26 seconds (or close to that depending on which book you read). But this is dependent on all that follows below.

You will get different behaviour from different SOs or blends, using different equipment, at different times

So it may well be that for that particular batch of that particular type of coffee, for the grind setting you set on your grinder for your own esp machine, that is all you are going to get out of it before it starts to blond.

It maybe there isnt anything else to it and there isnt anything wrong here.

Hope this is helpful.

[JavaB]

Re: so whats your idea on whats wrong here?

dsc,

Well my only comment is on your tamping.....

If (and it is not very often) I do a first tamp it is only to settle the grinds ( a bit more than the weight of Gregs tamper)...

The real tamp is one only - not NSEW (4 tamps) as that will generate "fault lines" down through the puck where the tamps overlap..... and can cause a little vertical channelling along these lines (and premature blonding)...

You need a fitted tamper - and one tamp only (I found it made a HUGE difference) and when you polish (if you must) - use only the weight of the tamper.... again to prevent disturbing the puck.....

My 2c worth.

[dsc]

Re: so whats your idea on whats wrong here?

Hi,

Thanks for the quick replies

Curmudgeon: it may be, but the thing is that I get fast blonding on any coffee I use. I can use 1 day old roasts and still get the same results, thats why it seems wierd. And Ive seen a lot of Classic extractions which gave a thin stream of coffee, without blonding or growing rapidly.

JavaB: I think I remember a thread here on the forums (and I think you were the author) that said tamping once is the best thing. The problem is that the "one tamp and one tamp only" works on the authors certain machine and its possible that it wont work on different ones. I tried two things today:

no split dosing: just pour the dose into the basket, distrubute and tamp NSEW. This gave almost the same results as double tamping with 20kg of force, wierd? shouldnt the double tamp (especially that I tamped quite hard the first time) give slower pours?

one tamp only: but this time I reduced the dose to 17g, a bit fast, the cone got bigger in the middle of the extraction, no signs of massive channeling, pretty good I guess.

I will experiment with the one tamp method and see how it works.

Cheers,
dsc.

[Thundergod]

Re: so whats your idea on whats wrong here?

dsc a single tamp is not a one machine strategy.

[JavaB]

Re: so whats your idea on whats wrong here?

no split dosing: just pour the dose into the basket, distrubute and tamp NSEW. This gave almost the same results as double tamping with 20kg of force, wierd? shouldnt the double tamp (especially that I tamped quite hard the first time) give slower pours?

dsc,

Yep, with two tamps you should get a much slower pour.... in fact when I tried it (some time ago) a double tamp produced a ristretto where the single tamp was the normal espresso.... same grind, same volume of coffee and same tamp force each time.... just two dose/tamps

Im guessing here, but the second, NSEW tamp, is probably breaking up the first tamp somewhat and you are getting channelling - but not the kind which gives little squirts from the bottomless PF in all directions - just a tendency for a bit more water to take certain paths (along the fracture lines rather than just at single points).... and overextracting along those paths - leading to earlier blonding.

The second full pressure tamp is also almost certainly leading to horizontal channelling between the two layers..... far better if you can just use one tamp.

[Dimal]

Re: so whats your idea on whats wrong here?

Hi Tom,

I believe that until such time as you can acquire or manufacture a "fitted" tamper for your particular baskets, you are always going to be behind the 8-Ball in this area of barista skills. Do you have access to a lathe or know someone who could knock you up a decent tamper base? With your other very handy skills you could probably make a very nice handle to suit Im sure. Anyway, a fitted tamper just makes one important part of the process a lot easier to apply on a consistent basis and thats got to be a good thing.

Cheers Mate,
Mal.

[lucinda]

Re: so whats your idea on whats wrong here?

Tom, did you try upping your dose to 20g in the double basket? Anytime I use less than this I get much the same problems with early blonding etc.

I think I have said before to try upping the dose to 20g (not sure if it was you). I cannot remember the timing of my extractions but I dont think they are much more than 18-20 sec. With some beans even less.

I tamp twice - the first to settle the grounds the second, harder one to form the puck nicely.

[dsc]

Re: so whats your idea on whats wrong here?

Hello,

Well tried the single tamp and I have to say its worse than using two tamps. I got some squirts and faster blonding. I think Mal is right and Im probably getting side channeling because the tamper is smaller than the basket. In fact the tamper is 58mm but that stupid Gaggia double is a bit wider on top (around 59mm or more) so I get quite a lot of space in between.

Lucinda: I tried different doses and 18,5g is the max I can pack without touching the screen when locking the PF in. Probably 20g would be too much to lock the PF. Really only 18-20s max? even with that ammount of coffee? sounds a little bit strange.

I dont know anyone who could make me a better fitted tamper, so I thought about changing the basket Found the famous LM double ridgless basket and it should be available tommorow from one online store. Maybe the shipping costs wont be so high and I will finally have a good double basket with perfectly verticle sides

Cheers,
dsc.

[Fresh_Coffee]

Possibly nothing?

Gday dsc,

Ive just had a quick skim of this topic  and Im afraid I am not confident the answer to your enquiry lies in changing the filter or the coffee press.

Yes, it will change the type of pour but its not a "fix" its just using a larger filter which holds more coffee and therefore contains more oil, so the blonding wont occur quite so quickly. Its not really a fix for any problem just changing the end result due to a change in the working parameters.

Im also not convinced that buying a larger press (tamper) will do anything. You can use small tampers & as long as youre careful to tamp around the edges you can still have good success in espresso making / while you are waiting to get yourself a better tamper  .

The equipment / system in total (this includes the coffee) should be able to brew coffee well without owners having to resort to buying / using very much larger than standard filters (the gaggia filter is already a large commercial double) and having to use tampers that fit to within 2 microns of the diameter of the filter......you shouldnt "have" to go to these lengths.

Someone above said words to the effect that there may not actually be anything "wrong" and the effect may be a result of your coffee VS your grinder VS your machine, and I wouldnt necessarily discount that advice as it could be quite right

Regardz,
FC.

[Thundergod]

Re: so whats your idea on whats wrong here?

dsc I dont think the LM basket has vertical sides.

Ive got the double and it appears to me to be slightly wider at the top.

Mr Pullman should be able to confirm.

Its a nice basket though and Ive been using it to replace the standard Expobar double.
It holds just a little more coffee.

[Dimal]

Re: Possibly nothing?

Someone above said words to the effect that there may not actually be anything "wrong" and the effect may be a result of your coffee VS your grinder VS your machine, and I wouldnt necessarily discount that advice as it could be quite right

Wouldnt be your evil twin would it FC? :

Mal.

[gregpullman]

Re: so whats your idea on whats wrong here?

TG: Yes slightly wider at the top. The genuine LM has a ridge and the diameter comes in below that ridge.

dsc: If you decide to go down the path of getting a fitted tamper I should be able to help in that regard, which incidentally should be a whole lot cheaper than buying all the equipment to do it yourself! As FC said its not a silver bullet but it does allow you to minimise one variable, which is a lot of what coffee making is about - eliminating the many variables involved.

[dsc]

Re: so whats your idea on whats wrong here?

Ola,

Thanks for the suggestions and ideas. I will stick to my Gaggia basket and Torr tamper for now and see how it works with different coffees. As you say maybe everything is ok and this is how extractions work on my rig. Maybe I will be able to buy a better machine in the future and compare the effects to my past extractions. Or maybe its because of my grinder. Who knows

Greg: thanks a lot for your offer I will definitely go for it, I just need some more money

Cheers,
dsc.

[lucinda]

Re: so whats your idea on whats wrong here?

I think you need to go back to basics and start all over again.

With the grinder - maybe you have done too many mods without understanding what you are doing. I am not being nasty, just trying to offer what I think may be going wrong.

I have not modified my equipment except for pulling off the steam wand attachment. Other than that it was just a matter of pract ice practice practice and learning to use my machine and grinder.