Gushing On Second Stage Of Shot

[dman777]

Sometimes when I pull a shot, the initial black stage will be slow and steady as it should be. But then when the stream becomes lighter(just starting to blond) it suddenly starts gushing.

This isnt all the time...just once in awhile.

This is on a Silvia and Compak K3 grinder. Beans are high quality and are always less than 2 weeks after roasting. Ive been pulling shots for about 3 months now.

What am I doing in my technique that would cause this sudden gushing in the second stage when the stream becomes lite?

[Barry O'Speedwagon]

Re: Gushing On Second Stage Of Shot

Maybe the beans are embarassed? Perhaps re-assure them as to their worth.

[iaindb]

Re: Gushing On Second Stage Of Shot

Thanks for the morning laugh Barry - lucky I wasnt sipping a coffee at the same time or it would be on the screen by now... Im just going to go and coo to my beans before I make a coffee ;D

Seriously dman, I used to get this quite a bit with a Breville combo (average grinder) with a narrow basket. Now I have a K3T and 58mm basket I see it much less, although it still happens from time to time. I put it down to the grind, basket size, and technique. OK I understand thats just about everything on your table, let me elaborate:

1. How do you store the beans? If they are top notch and <2 weeks, do you leave them in the hopper overnight? Do you clean out the grinder before the next shot?

2. Youre dose / tamp technique might need looking at - do you bang the pf to settle the grinds before tamping? Do you tamp twice? Are you absolutely sure youre tamping evenly? Are you grinding fine and tamping light? Are you overdosing?

It sounds like youre getting chanelling. This can happen for various reasons which is why I ask all the questions. A naked pf would help prove this, but I think its obvious from what youve described.

Consistency is the key - you need to know how to (almost) exactly reproduce the variables you did last time (like amount of coffee, temp, tamp pressure, etc). Its usually when you dont reproduce something exactly the same that problems happen.

HTH!

[dman777]

Re: Gushing On Second Stage Of Shot

Hi, lol....thanks. I have to state the beans because alot of people will question the quality and suspect that is the problem in which case its $not$.

I think it maybe the way I am tamping. Is it still channeling if the first stage comes smooth and even in a timely manner, but the next stage is gushing?

[David8]

Re: Gushing On Second Stage Of Shot

I think it maybe the way I am tamping. Is it still channeling if the first stage comes smooth and even in a timely manner, but the next stage is gushing?

As far as I know, yeah. The water initially encounters the correct amount of resistance, and you get a nice looking shot. Then all of a sudden it finds a weaker point, makes the channel, and all the water follows this channel.

And it all hits the fan... :P

David

[iaindb]

Re: Gushing On Second Stage Of Shot

Is it still channeling if the first stage comes smooth and even in a timely manner, but the next stage is gushing?

absolutely could be - chanelling can (and often does, unless youre an absolute newbie or have bad equipment) develop mid-shot.

[Fresh_Coffee]

Re: Gushing On Second Stage Of Shot

Stop analysing and worrying and enjoy the coffee

It will only ever be somewhere in Grind / Dose / Tamp. Change only one variable at a time, and see how you go.

And I am afraid it actually could be the coffee in that, it could be light on for density and thats just the way it is.....so you could try another blend or origin and see how that goes.

None of this stuff is black and white.

[iaindb]

Re: Gushing On Second Stage Of Shot

I assumed it tasted bad/different, and I assumed it wasnt a blend or origin issue because it only happens sometimes Consistency is good!

[Barry O'Speedwagon]

Re: Gushing On Second Stage Of Shot

Thanks for the morning laugh Barry - lucky I wasnt sipping a coffee at the same time or it would be on the screen by now... Im just going to go and coo to my beans before I make a coffee

No worries...I was feeling a bit flippant....I was actually going to post something serious but thought this is too hard. FWIW this happens to me every now and then (particularly if Im not paying attention to what Im doing) but usually tastes fine to me.

[Potis]

Re: Gushing On Second Stage Of Shot

For what its worth, I used to get some gushing after a brief smooth pull, which I put down to channelling, then I ground the beans slightly finer and the problem virtually stopped. Went from pulling a 15-20 second espresso to 28-32 seconds... far better.