# Targeting the correct grind



## destiny (Jun 4, 2015)

Hi,

So.. I've finally got some time to tinker a bit with my machine (Classic) and make a few necessary adjustments.

A bit of background than:

OPV mod now complete and set at ~10.3bar (may adjust again if necessary but couldn't dial it better), IMS screen and brass holder installed with machine given thorough clean and a set of new seals and gaskets everywhere.

I've been using Waitrose essential water since I had it.

My F5 is doing a great job as an on-demand grinder (no mods yet but my input is pretty much my output to 0.5g) but I am not quite sure if I am setting things correctly.

My adjustment collar has corrugations and this is what I currently use to dial/adjust by.

Double IMS basket, fresh beans at 14g and I get about 50g coffee in 22sec. I still get lovely thick crema, but the test is not quite there and it still feels like it's giving out a bit too much of a flow (judging by all the videos I've watched...).

When I do a bigger dose at ~17g, things start to improve but I tend to get more bitter and more sour shots.

A few questions about my grind - is it normal to get a few smal particles to get through the basket holes into the shot glasses?

Crema comes out fairly pale brown, but after standing for 20-30s before I manage to finish of the drink (milk and stuff) it gets darker.. is that normal again?

My puck still tends to be quite wet (even though I can get most of it in one lump) and sticks a bit to the basket, but a few times I did get it to be pretty dry I'd say.

I generally, don't get sour shots at 14g, but still can't get rid of the bitterness.. nor actually taste any sweetness.

Any suggestions how to improve?

Thanks!


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## Dylan (Dec 5, 2011)

I have never had particles, but I think it is a normal occurrence.

It depends on the bean, but pale brown crema can suggest an under extracted shot, and from your brew ratio that sounds likely. 16g is right on the bottom end of what the IMS basket is supposed to take. Try tamping your coffee and placing a 2p on the dry puck, lock this in and then remove it again, there should be a light indent on the puck, but not completely pressed in, this is roughly how much distance you want between your puck and shower screen.

Work on a 2/1 ratio. If you are using 18g then aim for 36g out over 25 seconds(ish) seconds. But this can vary a lot, I'm currently pulling 25g from 17g in 32 seconds.

I still dont taste sweetness in espresso, and barely in a flat white, doesn't matter if its me or a skilled barista making it. Everyone's palette is different.

Dont worry about wet pucks, at all.


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## destiny (Jun 4, 2015)

Dylan said:


> 16g is right on the bottom end of what the IMS basket is supposed to take. Try tamping your coffee and placing a 2p on the dry puck, lock this in and then remove it again, there should be a light indent on the puck, but not completely pressed in, this is roughly how much distance you want between your puck and shower screen.


Thanks Dylan, will give it a go tonight. That basket is meant to be 14-17g range so not sure if it will take more than 17? If let's say I'd dose 17g and have deep indent from the 2p coin, should I tamp harder or reduce the dose?


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## Dylan (Dec 5, 2011)

destiny said:


> Thanks Dylan, will give it a go tonight. That basket is meant to be 14-17g range so not sure if it will take more than 17? If let's say I'd dose 17g and have deep indent from the 2p coin, should I tamp harder or reduce the dose?


I thought the IMS double was 16-22, but if yours is 14-17 then just experiment with the coin test as a starting point and then the result in the cup. 18g will indeed almost certainly be too much for a 14-17g basket.

Edit: sorry to answer your question, reduce the dose


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## destiny (Jun 4, 2015)

So.. the results are in









17g seems like the perfect dose, 2p only leaves a little indent. A shot of approx 37g was done in 21sec.

Next one I had to do on the remains of my coffee so a 13.5g shot only and at 27g it was pulled in 10.5sec.

Both tasted ok, but I had a bit of a sour note in both.

New 1kg pack of coffee awaits but need to sort out my grinder first.

The flow was nice and slow on shot 1, but the 2nd one felt a bit rushed.


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## Mrboots2u (May 10, 2013)

Ok so the second shot was faster as you dosed less coffee than the first

less coffee to offer resistance , water went through quicker > sourer shot

the first shot was sour as was a bit quick i suspect

with the new coffee , if its different prepare to adjust the grind again

go for a shot 25-35 seconds and taste

and enjoy


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## MWJB (Feb 28, 2012)

Thy both seem a little quick to me. Try going finer.


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## destiny (Jun 4, 2015)

Well, I though Id need to go finer but it already seemed like very fine. Im barely a few deg out feom zero position on my collar.

Will most likely try tmrw and post the shots of the different grinds.


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## MWJB (Feb 28, 2012)

Pics of the grinds won't be as helpful as shot times vs shot taste.


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## robashton (May 9, 2015)

destiny said:


> I generally, don't get sour shots at 14g, but still can't get rid of the bitterness.. nor actually taste any sweetness.
> 
> Thanks!


I've not seen anybody else point this out - but if you're gushing coffee through at the rate you are you'll likely have a combination of over and under extracted coffee which will usually either be perceived very strongly as "bitterness". I used to mix sourness and bitterness up a lot back when I first started drinking spro because the strong flavours make it much harder to perceive the difference. Relying on taste alone (without tasting a shots pushed to either side of a generic target) can be a bit difficult under those circumstances.

I'll not step in with my own solutions/recommendations as everybody has already done that - if you manage to do as these folk say happiness wil result.


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## Dylan (Dec 5, 2011)

As above, tighten up the grind, but just a tad and see if you can get your shot to pull in the 25-35 second range.

You can also try a harder tamp, but there are varying opinions to how much this this will affect the result.


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## robashton (May 9, 2015)

Dylan said:


> You can also try a harder tamp, but there are varying opinions to how much this this will affect the result.


And scientific research pointing out that it matters very little: http://socraticcoffee.com/2015/07/the-impact-of-tamping-pressure-on-espresso-extraction/

(Assuming obviously that you've got an even tamp action and you're not breaking the puck in other ways)


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## Dylan (Dec 5, 2011)

robashton said:


> And scientific research pointing out that it matters very little: http://socraticcoffee.com/2015/07/the-impact-of-tamping-pressure-on-espresso-extraction/
> 
> (Assuming obviously that you've got an even tamp action and you're not breaking the puck in other ways)


Cant get much more scientific that that!

I have read in other posts, and it is my own observation that the first drops can take a little longer to appear with a hard tamp, but the general consensus is in line with that link in that tamping pressure is not what is used to be made out to be.

Also, I think quite a few use significantly less than a 5kg tamp.


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## destiny (Jun 4, 2015)

Right, my F5 is now geared up to single dosing, but that took a bit of time so only got time to pull and try a few shots today..

16.6g ground, 35.8g out in 34.2sec, shot was sour but no bitterness

I've backed off the grind a bit and did

17.3g ground, 35.1g out in 22.2sec, same as above, but tasted a bit better I think

last was 17g in, 35.2g out in 20s. Crema had very sour taste, still no bitterness and comperable to no 2..

I think the flow is nice on any combination..


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## GCGlasgow (Jul 27, 2014)

Maybe try just changing one variable at a time e.g keep same grind amount in and time, change amount out then play with other variables


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## risky (May 11, 2015)

destiny said:


> Right, my F5 is now geared up to single dosing, but that took a bit of time so only got time to pull and try a few shots today..
> 
> 16.6g ground, 35.8g out in 34.2sec, shot was sour but no bitterness
> 
> ...


As GC said, you need to lock that dose down. Say, 17g and do not change it. Always 17g, all the time. One less variable.

Also, regarding the crema, it always tastes horrible.

What is the coffee you're using? At 17g > 35g it could well be underextracted which is causing the sourness. Leave your grind the same and see how 17g > 40g tastes?


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## MWJB (Feb 28, 2012)

destiny said:


> Right, my F5 is now geared up to single dosing, but that took a bit of time so only got time to pull and try a few shots today..
> 
> 16.6g ground, 35.8g out in 34.2sec, shot was sour but no bitterness
> 
> ...


You're grinding coarser again? Rather short shot times. You were still sour at 34sec, so why not try a shade finer still than that?

The flow can't look any better than the shot tastes.


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## destiny (Jun 4, 2015)

My balance has a bit of a lag and I time the shots manually on my phone so even on the last one when I thought I'd manage to stop in time, I've gone over


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## MWJB (Feb 28, 2012)

Stop by weight/ratio, not time. Record time.


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## destiny (Jun 4, 2015)

MWJB said:


> Stop by weight/ratio, not time. Record time.


That's what I'm doing but I usually press the stop button on the stopwatch too


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## risky (May 11, 2015)

MWJB said:


> You're grinding coarser again? Rather short shot times. You were still sour at 34sec, so why not try a shade finer still than that?
> 
> The flow can't look any better than the shot tastes.


I'm curious because we're recommending different solutions.

17g > 35g > 34s and there is sourness.

My normal solution would be to push the yield, say aim for 40g out and reassess (this is due to watching Mr. Perger's barista hustle on this topic in which he says get the yield right, then change the grind)

You're recommending increasing time by grinding finer but going for the same yield?

I'm just curious as to people's reasons for which way is better. Admittedly, before I watched said barista hustle I hadn't really considered yield as a variable. I always aimed for 17 > 34 and adjusted grind to change the shot time and therefore flavour.


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## Mrboots2u (May 10, 2013)

Your both trying to increase the extraction yield to get to sweetness . Just using water through the the coffee or increasing strength ( finer grind > longer shot time )

Changing different variables to get there

One will be stronger and have possibly more mouthfeel

One will more than likely weaker , less mouthfeel and Strength


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