# Baby Class Shot Diagnosis



## clickhappy (Feb 1, 2012)

Hi, I have had a Gaggia Baby Class D for the last couple of years and am still struggling to make decent espresso.

I began with a Dualit grinder which even with the burr realignment mod couldn't grind finely enough so it wasn't long before I ordered a MC2 doserless espresso grinder, now I could pour correctly timed espresso/ristretto shots with decent crema but the taste was very sour. It turned out I had serious channeling issues although not completely resolved, have been minimised by carefully dosing, knocking and tamping. I then bought a bottomless PF to help the diagnosis which certainly helped me dial in my dosing technique and I can now regularly achieve lovely 30 sec tiger striped shots with good crema but I am still struggling to get rid of the sour taste.

I have attempted temperature surfing and have bought a thermocouple to help me figure out what was happening but am really struggling. I think I get around the correct temp with a cooling shot pulled from a warm machine, then waiting for 20 seconds after the light has come back on.

I think the machine may be delivering more pressure than is ideal but this model does not have an adjustable pressure valve.

I am using fresh beans from Has Bean (in my mug subscription) maybe i am using them too soon after roasting, within 1 week?

Thanks,

Tom


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## garydyke1 (Mar 9, 2011)

I find more palatable espresso from beans rested 10-18 days but your 7 days should be enough to tame the acidity.

What dose and yield are you using / obtaining in 30 seconds ?


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## clickhappy (Feb 1, 2012)

Thanks for the reply, I usually have around 17g dose although I have not weighed it in a while and between 1 and 2 oz yield


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## garydyke1 (Mar 9, 2011)

Dose versus yield will have a huge impact on the sour/sweet/bitter/acid flavour balance.

I recommend you fix (and weigh) dose to within at least 0.5g tollorance, perferably 0.1g.

Then work on extracting 25g, 27g, 29g, 31g tasting each one and noting which you like best.

The play around with extraction time to fine tune. Where abouts in brum are you?


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## mookielagoo (Dec 12, 2012)

clickhappy said:


> Thanks for the reply, I usually have around 17g dose although I have not weighed it in a while and between 1 and 2 oz yield


Hi Tom,

Gary is spot on about the relationship between dose and yield...I started out filling the basket without too much attention to dose weight (as that's what ive seen on web etc)...my shots were sour and unpleasant...so i started weighing the grind in a shot glass first and using a stop watch to see the extraction in play into x2 1oz glass shot glasses. I worked out that my IDEAL grind weight is 14g. (rightly or wrongly, Ive completely ignored the 'dry' vs 'wet' puck debate).

This morning, Ive just pulled a stunning double with the creamiest of heads on a 10-11g dose in 28 seconds!! (twas like angels singing in my mouth!!!)...I too have started using an MC2 and i'm loving it!!! my goodness, what difference it makes!!!...and I've also realized that the tamp pressure doesn't need to be too hard... a firm twist of the wrist is all that's needed using non pressurized baskets. Regards Mark


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## rmwkenefeck (Nov 25, 2012)

You might want to try using some more forgiving beans. Not sure exactly which you have but some from hasbean can be hard to get spot on. A lighter roast seems to be less forgiving in my hands - can be good when right though.


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## clickhappy (Feb 1, 2012)

Thanks Gary, I hadn't considered weighing the amount of espresso extracted.

I live in Harborne.


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## garydyke1 (Mar 9, 2011)

clickhappy said:


> Thanks Gary, I hadn't considered weighing the amount of espresso extracted.
> 
> I live in Harborne.


I'm in Quinton ! Less than 2 miles


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## clickhappy (Feb 1, 2012)

It's a small world. We're spoilt for good cafes here in Brum, 6-8, York, Urban Coffee Co, Brewsmiths to name a few.

Any favourites?


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## garydyke1 (Mar 9, 2011)

clickhappy said:


> It's a small world. We're spoilt for good cafes here in Brum, 6-8, York, Urban Coffee Co, Brewsmiths to name a few.
> 
> Any favourites?


Spoilt indeed. 6/8, yorks kitchen, brewsmiths and saint all faves


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## clickhappy (Feb 1, 2012)

I fixed my dose at 15g and 30 sec pour, only changing the grind settings:

- 50g extraction, a bit thin but not the flavour was ok,

- 40g less thin better flavour although a little channeling

- 30g undrinkable, very sour

All pucks were pretty wet and I did my best I keep the temperature the same.

OPV has not been adjusted (I don't think this model is adjustable)


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## RoloD (Oct 13, 2010)

Some HasBean beans are just sour - I've had plenty of undrinkable HasBean shots in cafés that are supposed to know what they are doing.

Try some different beans.


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## MWJB (Feb 28, 2012)

clickhappy said:


> I fixed my dose at 15g and 30 sec pour, only changing the grind settings:
> 
> - 50g extraction, a bit thin but not the flavour was ok,
> 
> ...


If the flavour was good at 40g from 15g dose, then you still need to grind finer to get that same degree of extraction at ~30g output. A smaller dose will also extract faster - maybe keep the grind the same & see if 14.5g dose &

It sounds like you are under-extracting, so the options are finer grind, smaller dose, more water put through the puck (which it would seem that you don't want due to the lack of body you'll get).


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## Wando64 (Feb 28, 2011)

Try beans from a different roaster. I personally do not like lighter roasted coffee such as that of Has Bean or (to a lesser extent) Square Mile. At the moment I am enjoying beans from Coffee Bean Shop, but there are other too. Some people are perfectly happy with lighter roasted beans. I am not one of them and I also find them (often) sour for espresso. I prefer chocolaty, creamy and nutty in my cup, not fruity and citrusy. (I think I might have invented a few new words there)


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