# Espresso gushers



## PolarBearDave (Jul 24, 2012)

I've been having real trouble with the last two Hasbean In My Mug beans in my Silvia (Costa Rica Finca de Licho 2012 & El Salvador Finca La Fany Bourbon). Whatever I do, I nearly always seem to get a gusher. 30g in 15-20 seconds using an 19g dose in an 18g VST basket.

My grinder's a Vario which normally sits around 2 Macro D Micro. I've gone from here down to about 1 Macro H Micro but it makes next to no difference in the shot timing, even after grinding a few shots at the position. I've got an even distribution and solid tamp (By Knock VST tamper) so I don't think that's to blame.

I've checked my scales and they're fine. The Vario adjustment is working as you can hear it start to labour as you reach to fine end of the scale. The Silvia's pressure's set at ~9 bar. I also had some Monmouth beans kicking around which pull as expected at the same dose and grinder setting.

The only thing I can think to explain it is under dosing the basket, with the coffee not expanding to fill it properly so the grind doesn't affect the flowrate. However, I'm weighing the beans and it also looks about right in the basket. The puck at the end also looks alright - knocks out in one piece.

I'm somewhat at a loss of what the problem is, and wasting lots of beans in the process. Any help would be appreciated!

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## MikeHag (Mar 13, 2011)

Or equally could be overfilled and ground too fine, so the water punches thru. What happens if you do 18g with the same grind?


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## garydyke1 (Mar 9, 2011)

With the 18g VST I found 18.5g optimal for the licho, after a weeks settling reduced to 18g, quite a basket filling coffee. Mind you my e61 probably offers different headspace to yours. I'd try 17g or 17.5 with slightly Finer grind and see how you get on.


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## jimbow (Oct 13, 2011)

What Mike and Gary said. If you lock your prepared portafilter into the group and then take it straight out again (without running the shot), what does the surface of the puck look like?


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## PolarBearDave (Jul 24, 2012)

I tried an 18g dose of the Licho this morning in the 18g VST, ground finer than I ever normally would (1 Macro S Micro), but it still gushed out 32g in about 18 seconds.

To test again, I used a 2 week old bag of Monmouth espresso blend at what I would consider a normal grind - 19g at 2 Macro C Micro (never have to normally go beyond 2A and 2I). Despite being older and much coarser, this give a 32g shot in 25 seconds.

I checked the headspace of the dry puck with the 19g Monmouth shot, which filled the basket a few mm more than the Licho when tamped (judged by top of tamper position). I've a recessed shower screen screw, so I put a pound coin on the puck and locked it in. On removal, it had a very slight imprint of the coin which I believe is fine.

So I'm still somewhat at a loss. I've never had this problem before with any other beans, only these last two Hasbean bags.

I suppose different groupheads in combination with the VST baskets slide the centre of the +/- 1g dosing band up or down. I have struggled with down dosing previously in general, hence why 19g is my standard for this basket. Perhaps whatever way my grouphead is has slid the optimum fill upwards?

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## garydyke1 (Mar 9, 2011)

could you post a video of the espresso making routine and a 'gusher'?!


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## MikeHag (Mar 13, 2011)

What I was getting at was that grinding too fine could be contributing. Too much resistance. I'd be trying to reduce resistance thru a lower dose and/or coarser grind. But no guarantees :/


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## PolarBearDave (Jul 24, 2012)

I think I see what you're getting at.

I always thought to slow a shot down you needed to increase the resistance by either increasing the dose or grinding finer, or both. If you go too far, I expected the machine to choke and have nothing come out.

But what I think you're saying is, alternatively the puck might fracture with all the resistance, and the water gushes through the fractures?

I'll try going the other way by grinding coarser than normal and cutting the dose when I get home this evening to see what happens. If this doesn't help, I'll try Gary's suggestion of posting a video of my attempts to see if there's any clangers in my technique. Thanks for your help!

David


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## Milesy (Mar 8, 2012)

Are the beans too fresh? I now prefer my beans for Espresso two weeks after roasting. Anything fresher and I get a big gushy cone.

I also found neither the fine grind / light tamp, and course grind / heavy tamp worked for me. I have found a sweet middle spot for me.


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## Jez W (Jul 2, 2012)

I have also noticed that my Espresso gushes when using fresh beans - I always thought it was down to incorrect grind or tamping. Is this a common problem with Fresh beans and anyone know why?


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## garydyke1 (Mar 9, 2011)

Sure beans can be too fresh for espresso

http://www.home-barista.com/coffees/making-espresso-with-ultra-fresh-coffee-vs-rested-coffee-t9833.html


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## PolarBearDave (Jul 24, 2012)

The Licho beans I'm trying with were roasted 17th Aug and opened 21st Aug - 12 days old now. I try to wait 4 days or so before opening, but depends if I've got any other coffee!

I normally start with a 19g dose in the 18g VST with a ~15kg tamp (although I'm sure this sneaks up). I then adjust the grind (simply finer for slower, coarser for faster) to get a decent 30g shot in ~25-30 secs which I use as a reference taste. From here, I try and think what changes need to be made.

I posted a video of one of the earlier gushers from the naked portatfilter - not a pretty sight!


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## garydyke1 (Mar 9, 2011)

Not a pretty shot indeed!

Have you been able to choke your machine with the Licho?


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## PolarBearDave (Jul 24, 2012)

No - that's what I've been struggling to do. I grind finer and finer and it doesn't slow down!

I think what Mike is saying that increasing the resistance so much can cause the puck to just split under the pressure with the water gushing through.

Going to try the opposite of coarsening the grind beyond my usual range to see what that does - not something I would have thought of!


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## Milesy (Mar 8, 2012)

You should be able to grind fine enough that you can choke the machine without even having to tamp? I can do that with my MC2 grinder and Gaggia. Literally just a tap on the counter to settle and then lock in and I can get a choke then work backwards with grind and tamp. And this is at standard 9bar(ish) pressure.


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## PolarBearDave (Jul 24, 2012)

Maybe that's where I'm going wrong. I'm still giving it a heavy tamp when grinding fine - one of the few variables I thought you could keep constant!

All good thoughts for trying this evening - thanks!


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## garydyke1 (Mar 9, 2011)

Just grind as fine as you can to choke the machine completely, then back off 1 click/setting at a time until you get a flow.

If you cant choke the machine then I'd blame the grinder ; beans and/or roast


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## PolarBearDave (Jul 24, 2012)

I finally managed to get the Finca La Fany to slow up by grinding really fine, back to the mid 1 Macro setting on the Vario (which I had tried previously with no success). Whilst it no longer gushes out, it tastes absolutely crap! Acidic, bitter, thin - no hint of sugar at all.

I think it must be down to using it just too early - 5-6 days past roast. Never noticed this so much as on the last 2 Hasbean IMM bags. I normally have to grind coarser the fresher the beans. Aww well - only have about 1 or 2 shots left in the bag. Will be waiting longer before trying to use the next In My Mug! Might be useful if Steve gave an indication of how long to let it rest in his video....

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## repeat (Nov 14, 2009)

I've heard the VST baskets are pretty tough to get used to from a tamp, distribution perspective. On another forum they were saying better results needed 18g or more in the basket. I have the Finca at home and its running fine with my SJ. I have a VST basket arriving today so I'll report back later if the basket affects anything. I would also do as suggested above, tamp reasonable (not too heavy), choke the machine and then back off.


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## garydyke1 (Mar 9, 2011)

PolarBearDave said:


> I finally managed to get the Finca La Fany to slow up by grinding really fine, back to the mid 1 Macro setting on the Vario (which I had tried previously with no success). Whilst it no longer gushes out, it tastes absolutely crap! Acidic, bitter, thin - no hint of sugar at all.
> 
> I think it must be down to using it just too early - 5-6 days past roast. Never noticed this so much as on the last 2 Hasbean IMM bags. I normally have to grind coarser the fresher the beans. Aww well - only have about 1 or 2 shots left in the bag. Will be waiting longer before trying to use the next In My Mug! Might be useful if Steve gave an indication of how long to let it rest in his video....
> 
> Sent from my iPad using Tapatalk HD


What extraction ratio and in what shot time? (Sounds like under extraction = ''Acidic, bitter, thin - no hint of sugar at all'')

...shots of La Fany in my experience have been incredibly sweet and toffee-caramel on the finish, not particularly acidic

Im sure if you email Steve he will provide advise on rest times.


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## Milesy (Mar 8, 2012)

repeat said:


> I've heard the VST baskets are pretty tough to get used to from a tamp, distribution perspective. On another forum they were saying better results needed 18g or more in the basket. I have the Finca at home and its running fine with my SJ. I have a VST basket arriving today so I'll report back later if the basket affects anything. I would also do as suggested above, tamp reasonable (not too heavy), choke the machine and then back off.


I dose 18g exactly into a 18g VST (ridgeless) basket and tamp using my made by knock VST tamper. One single tamp. No tapping or retamping. One tamp. Lock in. 30g cofee in about 35 seconds as it currently stands. Using beans that have rested a little I am getting absolutely perfect extractions almost every time now. The extraction time is not a big point for me. I go by taste now and with my current bean I like it as it is. Since the new basket and tamper I am reproducing the same almost every time now.


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## jimrobo (Aug 5, 2011)

I had all sorts of issues when I had the mignon and used an 18g vst. Most of those went when I upgraded my grinder but occasionally I get beans that do something similar to you. I go a slightly higher dose and tamp really light. Almost just a polish rather than a tamp.


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## garydyke1 (Mar 9, 2011)

Milesy said:


> I dose 18g exactly into a 18g VST (ridgeless) basket and tamp using my made by knock VST tamper. One single tamp. No tapping or retamping. One tamp. Lock in. 30g cofee in about 35 seconds as it currently stands. Using beans that have rested a little I am getting absolutely perfect extractions almost every time now.* The extraction time is not a big point for me*. I go by taste now and with my current bean I like it as it is. Since the new basket and tamper I am reproducing the same almost every time now.


This is generally a good approach however the OCD in me must suggest this experiment for anyone thinking of playing with extraction time as a variable:

Try obtaining 30g from 18g in 25 seconds & then 30g from 18g in 35 seconds (keeping everything else the same) - you'll be suprised the difference . Certainly some characteristics will be apparent in both shots but equally the balance of the shot (and mouthfeel) will be chalk and cheese.


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## ronsil (Mar 8, 2012)

garydyke1 said:


> Try obtaining 30g from 18g in 25 seconds & then 30g from 18g in 35 seconds (keeping everything else the same)


Absolutely agree with this one as well - Start with an optimum 25 seconds & vary this time up/down to find the taste you prefer.


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## repeat (Nov 14, 2009)

repeat said:


> I've heard the VST baskets are pretty tough to get used to from a tamp, distribution perspective. On another forum they were saying better results needed 18g or more in the basket. I have the Finca at home and its running fine with my SJ. I have a VST basket arriving today so I'll report back later if the basket affects anything. I would also do as suggested above, tamp reasonable (not too heavy), choke the machine and then back off.


Tested tonight using 18g VST ridgeless basket. Pour if anything was better. Produced more crema. Changed only the basket after making a double in the original basket. Tasted very similar.


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## Milesy (Mar 8, 2012)

garydyke1 said:


> This is generally a good approach however the OCD in me must suggest this experiment for anyone thinking of playing with extraction time as a variable:
> 
> Try obtaining 30g from 18g in 25 seconds & then 30g from 18g in 35 seconds (keeping everything else the same) - you'll be suprised the difference . Certainly some characteristics will be apparent in both shots but equally the balance of the shot (and mouthfeel) will be chalk and cheese.


Sorry I was just musing my own technique for myself not directing the OP obviously









At present I much like the 35 seconds pour than the 25 seconds. Richer and better mouthfeel for me (with this bean and roast anyway).


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## PolarBearDave (Jul 24, 2012)

Normal service is resumed. After finishing the Finco La Fany, I bought some London Coffee Roasters Espresso Blend yesterday with which I can choke the machine half way through the 2 Macro setting (where I was getting uncontrolled gushers before), and more importantly tastes good when I back it off. I don't know, maybe my little Vario does something funny with fresh. lighter roasts? Going to wait a week before trying the Kenyan Karatina.....


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## Danm (Jan 26, 2012)

On some square mile beans i brought recently on macro 1 micro 1 best i could manage was 18secs.

Not all beans are made equal. Bean density, roast etc all go into determining factors of how you dial-in .

Also, on the vario i don't think you can reliably use someone else's setting as they are calibrated slightly differently.

I am never out of macro 1 for espresso with micro around halfway...


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## PolarBearDave (Jul 24, 2012)

Yes indeed I agree.

I suppose it's my lack of experience of the range of beans out there. Seems I need to learn how to deal with beans like this that need to be ground towards the finer end.

Whilst the Varios may be calibrated differently, would the difference between 2 settings on the same machine be comparable? E.g. previously I would generally end up dialled in somewhere between 2A and 2M - 13 micro steps in the range. Now seems like this is going to be expanded....

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## garydyke1 (Mar 9, 2011)

PolarBearDave said:


> Normal service is resumed. After finishing the Finco La Fany, I bought some London Coffee Roasters Espresso Blend yesterday with which I can choke the machine half way through the 2 Macro setting (where I was getting uncontrolled gushers before), and more importantly tastes good when I back it off. I don't know, maybe my little Vario does something funny with fresh. lighter roasts? Going to wait a week before trying the Kenyan Karatina.....


Not sure how suitable the Karatina will be as espresso, typically these coffees are extremely bright (nb the roast colour isnt that light in this instance)


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## chimpsinties (Jun 13, 2011)

I've had similar experiences with my Vario where for one coffee I'll be at 2E then suddenly when I change coffee I've got to throw it over to something like 1E to get anything right out of it. That's just one of the downsides of using different coffees every time. If you stuck to one type there's be much less dialing between bags (although you may still need small adjustments as they age etc)


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## Beemer (Jun 19, 2012)

David,

I had exactly the same symptoms two weeks ago. I had been adjusting my Mazzer closer and closer to zero to try to slow down the pour to get 25 seconds. It was then that I read about puck channelling and other punch through symptoms that could be the cause. Water always takes the path of least resistance so if there is any weakness in a too fine heavily tamped puck then that weakness will resulting channelling. I then opened up the grind substantially and WOW! the next pour was sweet (as I like it). I had been convinced that grinding finer was the answer but it turned out I was wrong.

Ian


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## chimpsinties (Jun 13, 2011)

Don't forget grinding finer should also come with tamping with less force.


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## PolarBearDave (Jul 24, 2012)

Yes, I think this is the conclusion I came to just as I ran out of the beans! I had always believed that grinding finer and tamping harder was the answer to slow things down. Now finding backing off the tamping pressure at the finer end as suggested helps - thought this was one thing you could keep constant with all the 30lbs calibration mats/tampers etc!

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## mm27760 (Jul 13, 2012)

I have found this an interesting thread, I use a Compak K6.

I have set my grinder pretty fine so I actually get some grinds in the coffee.

I changed the burrs about a month ago so I know they are in good condition.

I tried stepping the grinder round to produce less fine grounds but the rate was then 2 quick, shots were coming out a 8 seconds.

I stepped it back to the previous position and it was back to 25 seconds shots.

Is this what other people finder the coarser the grind the quicker the shot or this another coarser grind where it will come back to a 25 second shot.


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## jimbow (Oct 13, 2011)

Generally speaking, yes, the coarser the grind, the faster the pour rate. However, the grind is actually just one of several variables that affects the pour rate. For a given filter basket, these other variables include dose (quantity of ground coffee in the filter basket), tamp pressure and pump pressure (on the machine). Usually, one would keep the pump pressure and tamp pressure consistent and vary the grind, and occasionally the dose (when required), to control the flow rate.


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## PolarBearDave (Jul 24, 2012)

As Jimbow says, generally the finer the grind (keeping the other variables constant) the slower the flow. However, this thread was about where this didn't appear to work - the flow was always too quick, even with a very fine grind. in this case, I found making the grind slightly coarser and tamping less hard gave a better result. However, this might not always be what happens.

I suppose it just illustrates that it is not always as simple as grind finer and tamp harder to slow down a shot.


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## RobD (May 2, 2012)

i had a similar problem with some Old Brown Javan, with courser grind would pour way to fast and under extract or with only a slightly finer grind was slow to start then would blond really quickly about half way through a 3oz pour, but all the time keeping the tamp the same

in the end i found i had to grind a little finer than normal but tamp about half as much force with just a light polish and it was nearly there just as i ran out of beans, i think that the grind - tamp balance is something that may only come with experimenting & experience, but tis quite rewarding when you get it right.


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## chimpsinties (Jun 13, 2011)

I bet over tamping is usually the problem when grinding fine. It basically makes the puck impenetrable which eventually cracks and forms a gusher or just doesn't let any through at all.


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