Exploding Coffee Puck

[acoggins Senior Member Find all posts View Profile Close acoggins]

Hi Everyone,

I cleaned my grinder the other day and am now having problems finding the right grind for it. In the process of churning through tons of coffee, Ive had a few pucks that tend to erm, explode.

What I mean by this is that I grind, dose, tamp and lock in the PF and hit the button, Immediately after the pre-infusion on my EM6910, the pf starts to edge right and would very quickly pop out if I didnt hold it in place and stop the shot.

When I pull the pf out, the puck is partly dry, but REALLY expanded, almost popping out of the basket. Whats going on?!

Does anyone know why this happens? My procedure is completely the same, Its only the grind that has changed.

Thanks,
-ACog (grumpy from lack of caffeine)

[jamver Senior Member Find all posts View Profile Close jamver]

Re: Exploding Coffee Puck

Try dosing down a little. It sounds like youre overdosing too much for the capabilities of the 6910.

[A_M Guest Find all posts View Profile Close A_M]

Re: Exploding Coffee Puck

Try dosing down a little.  It sounds like youre overdosing too much for the capabilities of the 6910.

I agree fully... I had the same thing happen to me today - Low on beans and could only get some Local supermarket stuff...

Thus mixed my last 250 with 250 of the crap.... Did not change my grind and forgot to adjust my tamp and fill level... Was steaming milk and hit the pour button (You can on a 6910) ... Opps the handle started to move....

Stooped the steaming of the milk ASP and Grabbed the PF Handel ... Sigh of relief.

Drink was OK.... And will last until the next batch of beans arrive Tuesday Midday...

Moral: Consider every thing twice and pour once.... Even then, something may still catch you out.

Remember, with a full PF lock it in and then remove... Just the slightest hint of the shower head or screw and then back the level off a bit....

[acoggins Senior Member Find all posts View Profile Close acoggins]

Re: Exploding Coffee Puck

*Sigh* I think Im back to square one with my grind/dose/tamp. Ive overfilled the PF a few times in recent days. I know just by looking that Ive overdone it, but foolishly I lock it in anyway.

I must say however, that this exploding puck didnt give me the impression it was overfilled.

[A_M Guest Find all posts View Profile Close A_M]

Re: Exploding Coffee Puck

Depending on the tamp, the grind and the beans (absorbency and swelling etc)... And in addition the amount of compression when forced into the Group head...

The results from water being forced into the mix, can have 100s of outcomes; of which a good coffee - is only ONE.

Thus it is a journey that we all undertake - Consistency.


As a Tea taster said in the paper the other day... Making coffee is way to complicated and too many factors outside of the product can affect the outcome. Hence he went from Coffee to TEA... His comment was that - with good tea leaves, it was easy to reproduce a quality drink regardless of the Equipment and Operator; unlike Coffee.

[Andy CoffeeSnobs Owner Find all posts View Profile Close Andy]

Re: Exploding Coffee Puck


AngerManagement... I would have thought the real moral was to not let your beans get low enough to cause supermarket coffee to appear!

ACog... if it isnt the dose, the seals are ok on the machine then I would expect that your grind is a little too fine and you are building too much pressure in the group handle*.

It should feel something like salt and pepper between your fingers not flour.



* PS: I have been told that Australians use group handles in group heads. Our American cousins use portapotties porta filters

[Ray_C Senior Member Find all posts View Profile Close Ray_C]

Re: Exploding Coffee Puck

If its the same thing that I once experienced with my long despatched sunbeam its probably a worn group head and handle assembly. Mine did exactly the same thing but by then I had had enough of the piece of crap and did the only respectable thing left to do.. lose it! The sunbeam that is...

The isomac I picked up off that other place is a far cry from the wanna be sunbeam ever was, there is just no going back and the pid is the bomb as little home machines go. all at less than half the price for a 6910...

Ray.

[A_M Guest Find all posts View Profile Close A_M]

Re: Exploding Coffee Puck

AngerManagement... I would have thought the real moral was to not let your beans get low enough to cause supermarket coffee to appear!

Ya well sometimes the Wife fails in her roll as Kitchen Moderator

However - rest assured that she has been disciplined and that it should not happen again. Good help is hard to find these days

I must say however, that this exploding puck didnt give me the impression it was overfilled.

1: Should not have to lock it in by force..
2: If not over filled, then as Andy said - Too fine will also cause excessive pressure to build up..

Have you performed a full clean ?

[acoggins Senior Member Find all posts View Profile Close acoggins]

Re: Exploding Coffee Puck

Well I think my group seal might also be wearing in. If I put the rubber disc in and do a back flush, the group handle (portafilter or whatever) moves slightly. The handle also locks off slightly to the right now.

I took the showerhead off, gave it a good scrub and inspected the seal. It all looks ok.

To complicate things, while trying to redial the grinder (and my dosing) in again, I ran out of my usual st ali BC blend which is the ACog house blend. I had to resort to using my first corretto roasted beans, which hadnt rested enough. So I was working with all variables changing.

I worked my way through 250 grams of that to finally achieve one beautiful shot this morning worthy of espresso p0rn stardom. Pitty the brazil bourbon bold didnt seem to cut through the milk. Nice as a ristretto though.

Yeah, tea might be easy, but oh so unrewarding.

[A_M Guest Find all posts View Profile Close A_M]

Re: Exploding Coffee Puck

To complicate things, while trying to redial the grinder (and my dosing) in again, I ran out of my usual st ali BC blend which is the ACog house blend. I had to resort to using my first corretto roasted beans, which hadnt rested enough. So I was working with all variables changing.

As TG always says - One thing at a time...

[acoggins Senior Member Find all posts View Profile Close acoggins]

Re: Exploding Coffee Puck

As TG always says - One thing at a time...

Absolutely. Bit hard not to when you run out of beans though. Youd know all about that wouldnt you AM? How was your supermarket coffee?

[A_M Guest Find all posts View Profile Close A_M]

Re: Exploding Coffee Puck

As TG always says - One thing at a time...  

Absolutely. Bit hard not to when you run out of beans though. Youd know all about that wouldnt you AM? How was your supermarket coffee?

Crap and I would have been better just enjoying the last 250g of the good stuff.

Note to self. DO not mix the good with the bad.

[Dimal Mal Find all posts View Profile Close Dimal]

Re: Exploding Coffee Puck

Crap and I would have been better just enjoying the last 250g of the good stuff.

Note to self. DO not mix the good with the bad.

Not like you to fall for a trap that catches young players "AM".... Mixing good with bad never raises the bar of the bad, just ruins the good

Mal.

[A_M Guest Find all posts View Profile Close A_M]

Re: Exploding Coffee Puck

/me  

Had a stuck Puck today as well...

Dosing / Grind and Bad beans...  I need to get back to work...

/me needs a life.

[Andy CoffeeSnobs Owner Find all posts View Profile Close Andy]

Re: Exploding Coffee Puck

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