# Is my tamper too small.



## Milesy (Mar 8, 2012)

I just measured my tamper and it is 54 and my basket is 58. After I tamp there is a lot of grounds on the side Walls. I don't bang the PF but rather use the tamper to gently push the grounds off all round before polishing.

How much is this likely to affect my puck and pour? My channelling issues are still hit and miss.


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## chimpsinties (Jun 13, 2011)

It will make it almost impossible for you to get a decent puck. What machine have you got and what tamper is it? Please tell me you're not using the crappy plastic one that came with the machine? You NEED a 58mm tamper that fits your basket snugly. Ideally you want to be going for a single tamp followed by a light twisting polish


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## Milesy (Mar 8, 2012)

I got it from a coffee supplies store. They gave it when I got my bottomless PF from them and said it was perfect size. I have just noticed though that it really isnt.


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## chimpsinties (Jun 13, 2011)

"a coffee supplies store" - Do you fancy naming and shaming said store? Haha!


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## jimbow (Oct 13, 2011)

What people consider to be the 'perfect' size can differ rather a lot. For some people, 4mm is an acceptable tolerance but for others, who are measuring their tamper's diameter to the nearest 0.1 or even 0.05 millimetre, this will simply not be good enough.

There are different schools of thought regarding how much difference the fit of the tamper within the basket actually makes. I remember reading some writing on Home Barista where Andy Schecter was claiming a measured percentage difference in extraction yield from a perfectly fitting tamper.


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## Milesy (Mar 8, 2012)

Thanks. My pour starts good now. Beads evenly and then quickly goes to a single stream with striping all round. It then starts getting blonde at just one side of the basket. Always the right for some reason. Then the cone starts to gush and drop down far and then it swings from side to side. Any ideas on what to look at here?


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## chimpsinties (Jun 13, 2011)

Are you distributing the grinds? When my grinder was clumping I would put about 1/3 in the basket then distribute with a pin, then tap to settle, then repeat that again twice until it was full. Only then would I tamp. Also it's important to tamp straight down in one fluid motion with a very light polish. Don't be tamping then tamping again and again. You're asking for a broken puck that way.

What are you using to grind?


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## Milesy (Mar 8, 2012)

P.s the beans are a week from roasting. Would this influence it?


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## Milesy (Mar 8, 2012)

I measured exactly 18g of grounds after grinding. (MC2 grinder). Used the WDT. Levelled off (This blend takes up slightly more room with 18g so I used the leveller back and forward gently compressing the grounds down until level. A straight level off would maybe be 17g with these beans. I do a straight tamp. This time I also tamped all four directions as the tamper is smaller, however it made no difference from the single tamp and polish.

Also how much do I need to worry about the loose grounds on the side wall after tamping?


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## chimpsinties (Jun 13, 2011)

It really depends how loose we're talking. Any chance of a picture?


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## Milesy (Mar 8, 2012)

Here you go.


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## chimpsinties (Jun 13, 2011)

That doesn't look too bad tbh.

When you said 4mm too small I thought it was going to be a massive gap. It would be a bit small for my liking but I think you can work with it.

Have you tried up dosing a bit? It looks like you've got abou 17g in there at the moment. Try with 18g or 19g and see if that improves things.

I'll try and remember to take a picture of mine tomorrow for you.


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## Milesy (Mar 8, 2012)

I can't get 18g of these fresher beans in without physically compressing the grounds down when levelling. 17g is what I get with stir and level. I did manage to get 19g in it before by pushing the grinds in. When I removed the PF the puck was still stuck on the showerscreen by itself.


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## jimbow (Oct 13, 2011)

Try using a lower dose, one that allows you to simply tamp once. There are quite a lot of grounds up the side of the basket so a very gentle NESW with the tamper might help remove them.

An imprint of the shower screen in the puck is okay after the shot because the ground coffee will have expanded during the shot but you should not get an imprint before the shot (putting the portafilter into the group and then removing it to inspect the top of the puck). There should be a small amount of head room between the top of the puck and the shower screen to allow the ground coffee to expand as it becomes wet during the shot and to allow a steady ramp up of the brew water pressure above the puck.


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## Milesy (Mar 8, 2012)

When I tried 16g and even worse at 15g I find it hard to get a consistent pull (harder that already is). I either get a complete choke or a complete gusher with very little variation in my technique.


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## chimpsinties (Jun 13, 2011)

This is what I find also. If I go 17g or below. I tried it this morning with 17g and although it wasn't a gusher it was still a bit quick. I got 2.5floz in 19sec.

I prefer to cram 19g in the basket by whatever means (this is what I was talking about before about filling it in 3rds and distributing and tapping the PF in between to settle the grinds so they fill all the gaps that way you can fit more in). Even if this does mean the screw from the shower screen touches the puck it makes the best coffee in my opinion.


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## Milesy (Mar 8, 2012)

I will try tonight. My new VST basket and tamper (matched) will be with me tomorrow as well.

I take it I need to forget about the WDT then?


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## jimbow (Oct 13, 2011)

chimpsinties said:


> This is what I find also. If I go 17g or below. I tried it this morning with 17g and although it wasn't a gusher it was still a bit quick. I got 2.5floz in 19sec.
> 
> I prefer to cram 19g in the basket by whatever means (this is what I was talking about before about filling it in 3rds and distributing and tapping the PF in between to settle the grinds so they fill all the gaps that way you can fit more in). Even if this does mean the screw from the shower screen touches the puck it makes the best coffee in my opinion.


I must admit, I seem to recall I used to have similar experiences, that lower doses in the standard basket used to frequently lead to channelling. I am afraid I cannot remember now exactly how I fixed it but I think it might have been in my distribution and tamping technique and/or grinder. Which grinder are you both using?


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## chimpsinties (Jun 13, 2011)

jimbow said:


> I must admit, I seem to recall I used to have similar experiences, that lower doses in the standard basket used to frequently lead to channelling. I am afraid I cannot remember now exactly how I fixed it but I think it might have been in my distribution and tamping technique and/or grinder. Which grinder are you both using?


Don't worry about me. I have no problems with my shots. You can see all my equipment in my sig. I'm just trying to help the guy out by passing on my experiences and what helped for me.


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## jimbow (Oct 13, 2011)

Sounds good







I was just trying to remember how I fixed my channeling issues and was wondering if the Dualit grinder I was using at the time was the cause. Thinking back though I think I actually fixed my issue through a change to the way I dosed, distributed and tamped.


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## Milesy (Mar 8, 2012)

I dosed to 19g there but I do get a small screw indent when locking in. Gusher.

Secnd attempt. Turned the worm drive just 4 turns more to finer. Took 20 seconds to get a stream started and had nice striping. It blonded after about another 20 seconds. I only achieved about 1oz of liquids. It tasted not bad though. The bitterness from the gushers were gone. It was a little sour but in a pleasant way but maybe missing some sweetness.

1. Only four turns seems a very little to go from gush to drip drip drip.

2. Is it possible it was actually variation in my distribution and tamping?

3. This 1oz was acceptable. Drank it where as the others were sinked. I would like maybe 1.5oz here at least. Can I bring it sweeter as well as increasing the volume sightly more with my current dose? Which is max.

I have a 18g VST basket coming tomorrow as well as a tamper to match the basket closely.

Many thanks again


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## jimbow (Oct 13, 2011)

I am not that familiar with the MC2 but 4 turns of the worm drive sounds probably about right for the difference you described. On most grinders the band for espresso grind tends to be very narrow with the difference between great and awful often being just fractions apart.

The 18g VST basket will certainly help with the sweetness. To make it sweeter you will need to grind finer but with that dose in your current basket this will lead to an even shorter shot. To make it sweeter whilst increasing the volume with the current basket you will definitely need to reduce the dose.


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## Milesy (Mar 8, 2012)

Thanks. I wont waste any more beans tonight until I get kitted out and home tomorrow.









To think I bought this Gaggia Classic and thought I was ready to go. Where does it end haha


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## chimpsinties (Jun 13, 2011)

jimbow said:


> To make it sweeter whilst increasing the volume with the current basket you will definitely need to reduce the dose.


Are you sure about this? I think the sweetness comes at the start of a shot, decreasing the dose will not help get more coffee while keeping the sweetness surely?


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## jimbow (Oct 13, 2011)

The sour taste that Milesy is currently experiencing suggests that the coffee is under-extracted and to get more of the caramel flavours and balance out the shot he will need to increase the extraction yield of the coffee. There are two main ways to achieve this: by grinding finer or by decreasing the quantity of ground coffee in relation to the brew water. In order to grind any finer in the current basket the dose will need to be reduced to compensate for the increased resistance in the basket from the finer grind. Moving to a VST basket might alleviate this requirement because the VST basket inherently has less resistance (the resistance is designed specifically for 17-19g of ground coffee)


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## chimpsinties (Jun 13, 2011)

Milesy said:


> I dosed to 19g there but I do get a small screw indent when locking in. Gusher.


By the way. When you did I can only assume you took the PF off to check and then put it back on to make the shot. If you'd just put the PF on and tried it without taking it off to check (or do it again with 19g and don't take it off to check in the first place) then it probably would have been ok. Taking the PF off messes up the seal the puck makes with the group head so it's no wonder you got a gusher.

Today I tried a 17g with finer does in the 18g VST basket. I got a 2oz in 25s weighing about 38g and I'd say it was one of the more sour shots I've had recently.


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## Anth.Caffe.Ginevra.UK (Mar 16, 2012)

I was once told by a very experienced barista who still competes in UKBC that he knew somebody who owned a tamper exactly the same size as the pf. He would keep the tamper in a cool place and flush hot water from the machine through the pf meaning it slightly expanded with the heat. This then gave him an unbelievable close fit when tamping.

I suppose you could go on forever in the quest for perfection. Sky is the limit!

Also there is the "staub tamp"...I practice this whenever I am using somebody's set up where there is an obvious gap.

But of course, I am no expert, more an enthusiast!!

Good luck.


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## Milesy (Mar 8, 2012)

Thanks everyone. My 18g VST basket came, and I also got my matching tamper from the link on the VST thread: http://www.madebyknock.com/buy.html the chap was passing through Glasgow at a conference today and actually came to my office to give me it. It is a very nice weight and balance, well made and fits the VST absolutely perfect. No grinds on the side Walls at all.

I done a 18g dose as I would like a little wiggle room for ageing beans. It started off slowly and dripping but at some point something happens and the small steam seems to channel and a big ugly swirling cone appears. When it is dripping I think it is over extracting and the crema is very dark, when the big cone appears the crema goes very light indicating under extraction?

Can you over extract with choking and then under extract in the same pour?

Is it possible the puck at some point is being disturbed and then allowing the gushing after what was a slow pour?

Thanks again


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## jimbow (Oct 13, 2011)

Some speed up during the pour is normal and the stream will turn blond naturally at some point. However, from your description it does sound like there could be some channelling. After the shot, what does the top of the puck look like, are there small holes in the surface or around the edge?

There a 3 main categories of flavour compounds in coffee (this is in fact a gross simplification but suits for the purpose of this explanation). These flavour compounds dissolve at different rates with the sour/acidic tasting compounds dissolving most quickly, the caramel/sweet tasting compounds dissolving relatively slowly and the bitter/burnt tasting compounds dissolving most slowly of all. A properly extracted espresso (neither under or over extracted) should taste very sweet with crisp, delicate acidity. If the coffee is under extracted then not enough of the caramel flavour compounds will have been dissolved to balance out the sour tasting ones and the espresso will taste tart and overly acidic. If the espresso is over extracted it will taste bitter where the bitter tasting flavour compounds have been dissolved.

I would suggest examining your dosing, distribution and tamping technique - Are you breaking up any clumps from your grinder and then carefully distributing the grinds evenly through the filter basket prior to tamping? What is your tamp like, are you doing multiple tamps or just a very simple, straight tamp?


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## chimpsinties (Jun 13, 2011)

As promised here is a pic.

This is 18g (of a very dark Brazilian roast) in my 18g VST using my 58mm Rocket tamper. That's just one nice clean tamp down and a slight light twist to polish.










Producing this which ended up as 2floz in 26 secs.


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## Milesy (Mar 8, 2012)

Thanks folks.

After the shot it seems like the puck is sitting at an angle and if you press it it seems like there is a layer separated at the top.

After some checking it seems I have been running at less than 9 bar as well.

Just now I grind into into cup at exact measurement, stir it up, then spoon it using a measuring spoon into the basket. Stir it up with a small safety pin. I then tamp just once now with my matching tamper. A small polish and that's all.


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## Milesy (Mar 8, 2012)

Ok the pressure is fixed to 9bar now (measuring and adjusting return flow back to tank from OPV)

Done my usual technique. Pulled a shot. Started very well and beaded all over the basket equally and started nice for about ten seconds. I then got spritzers right at the very edge and it blonded on one side only. The right side. Left side was still extracting nicely. All in I think it over extracted. It tasted very nice and chocolately but the aftertaste is a bit burnt and ashy. I think my grind is too fine as there were grounds in my cup afterwards.


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## jimbow (Oct 13, 2011)

It sounds like the brew water is finding a path of lesser resistance through the puck on the right hand side and so more of the brew water is running through that path compared to the rest of the puck. This is extracting more solids from the coffee in that localised area of the puck possibly even extracting too much (over extraction).

Try to aim for an even extraction of the whole coffee puck by distributing the ground coffee in the basket and then tamping once, straight down.


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## Milesy (Mar 8, 2012)

Thanis. That's what I am doing but I don't know if there is a bias I am putting on the left hand side for some reason.

After distribution what is the opinion of tapping on the work top to settle the grinds into place? After distribution through strirring they are fluffed up and I am not convinced they are equally distributed.


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## chimpsinties (Jun 13, 2011)

Why not try turning your portafilter around 180 degrees and tamp it next time. If you weak spot moves from right to the left then you know it's your technique and you can work on it.

Video yourself doing it? you might see that where you thought you were straight you're actually a bit bent (if you know what I mean)


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## Milesy (Mar 8, 2012)

Yeah I think you are right. I am using my right arm but with my elbow to the right of the PF. I think I will also try left handed and a few other ways.


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