# Gaggia Cubika brew temp way off. Any way to fix it?



## Dylan (Dec 5, 2011)

Hello everyone.

This year has sent me down the past of getting that perfect espresso, what started as just wanting decent coffee at home has turned into a little bit of an obsession.

However I started off down this path with a Gaggia Cubika as I got it for a good second hand price. I have since picked up an Iberital MC2 grinder, bottemless portafilter and some other stuff in pursuit of a better espresso. But I still seemed to be getting a distinct sourness to my shot, and the crema would look lovely but dissipate quickly.

I have just been testing the temperature of the water coming from the brew head and I'm shocked to find it's topping out at 140°F/60°C, as I understand the correct temp is between 92°C-96°C so this seems to be the source of my sour shot!

I have taken the machine apart to see if there was an obvious way to increase the brew temp but I am not familiar with the components and could not see a way to do so.

I am beginning to think I may have to replace the machine, but I cannot do this for a few months, so if anyone could help me out I would much appreciate it!


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## Glenn (Jun 14, 2008)

That's an extremely low temperature and could lead to the taste issues you have identified.

I know that in the Gaggia Classics the thermostat can be replaced with a higher temperature one.

gaggiamanualservice (a CFUK Member) will be able to advise if the Cubika thermostat can also be replaced.

In the interim, have you tried switching to steam for 30 seconds then back off and pulling a shot? This will increase the temp but is a temporary solution with only a low chance of consistency.


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## Dylan (Dec 5, 2011)

I have tried that but the temp still doesn't seem to be anywhere near right. I have to note at this point that I'm using a milk thermometer placed in a bowl below the brew head and I'm beginning to think part of it is just temperature loss, but 30° of loss seems a lot. But the water is too hot to put your finger under the brew head as it drips out, but easily cool enough once in the bowl below, so there must be some loss.

This all feels terribly un-scientific, is there a better 'accepted' way of measuring the temp of the water?

I think I'm going to remove the drip plate and see if I can get a more accurate reading from the water as it comes out.


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## Dylan (Dec 5, 2011)

Tested the thermometer in kettle water and it got to 90° which I think is roughly right. I just tried turning on the steam heat until the brew head ejected steam then tested this temp, the water was spitting from the brew head, like it was nearly at boiling point and this read was 90°.

Considering water can only reach 100° is it better to have it a little too hot than far too cold?


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## MikeHag (Mar 13, 2011)

You're right. You can't rely on the method you've described to measure brew water temperature.

- the probe is too slow and too inaccurate (and not calibrated right?)

- there is cooling from the air, vessel, time, etc (maybe some kind of kinetic energy loss resulting from the drop distance between shower screen and vessel, but it's 23 years since my physics A Level!)

60C is low and your finger test kinda proves it's not true.

On ebay you can get a fast response digital thermometer with k type thermocouple wires for something like a tenner. Might sound techy but isn't at all and you can attach the wire under the shower screen to get a better reading.

If it turns out temp is ok, maybe your burrs are blunt. This leads to bad extraction, yellow sour shots due to some grounds being under extracted and some over extracted (too little or too much coffee solids washed out of the grinds) due to a large variance in grind size and quality... beans are crushed when they should be cut. Was your grinder bought from new?


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## Dylan (Dec 5, 2011)

Yea, Iv'e just been browsing fast response thermometers on ebay, I may have to invest.

I was also beginning to question my grind, it is a brand new MC2, but I had noticed the crema cone was a bit large to start with and I understand this to be a sign of a grind that is too coarse.

I'm going to experiment more with the grind tomorrow, I'll never sleep tonight if I continue now


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## MikeHag (Mar 13, 2011)

Aah ok. Grind finer. Sour = under extracted = too coarse (sometimes







)

Aim for the standard 2floz/60ml in 23-30 secs ish.

Maybe you already Know that tho


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## Dylan (Dec 5, 2011)

Yea, my shot was coming out in 25 sec-ish, so I wasn't too worried, but I'm trying to eliminate this sourness now, so some experimenting is on the cards!

I also need a scale to be sure I'm getting the right amount of coffee in the filterbasket.

One thing that has confused me after buying a bottomless portafilter is that is seems to hold much more coffee than the one supplied with the machine, if the correct dosage is 14g for a double basket why would they hold different amounts? Also the longest setting on the MC2 does not seem to make enough ground coffee to fill the bottomless filter. I going to pop to the shops tomorrow and get a pocket scale to see if I'm getting the right amount of grinds from the MC2.

I also read that the walls of the filterbasket should be straight, which they are not in the Gaggia supplied basket. :/

Thanks for the advice so far, hopefully I'll end up with that perfect espresso!


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## MikeHag (Mar 13, 2011)

14g in a standard gaggia double basket is a red herring. You can get a few g more in easily... 18-19g is common. You can't rely on the basket to regulate the dose... at least not at first... and scales will help a lot with diagnosing problems.

It used to be that the happy donkey bottomless PF came with a triple basket, which can hold around 22-24g so maybe that's what you've got... although I'd read that these days they send just doubles.

Pocket scales from Has Bean are about £13 last time I looked. Great tool.

Sorry to keep suggesting new tools! Not necessary but help. But experimenting, as you plan to do, is best of all







Good luck. Ask more and will try to help if needed.


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## Dylan (Dec 5, 2011)

My girlfriend asked me if I thought I was getting fat when I bought bathroom scales last week. She wasn't particularly impressed when I told her it was so I could get my tamp pressure correct.

The right tools help you get the job done, seems to be the way I see it. Just picked up a pocket scale for £9 inc delivery from mymemory.co.uk. Now to convince my girlfriend I'm not selling drugs.

Oh and maybe it did come with a tripple basket, it does seem substantially larger, I may email the site to check, it doesn't say on the purchase page.


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## MikeHag (Mar 13, 2011)

At least she didn't ask if you thought SHE was getting fat







#dangerousground


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## Dylan (Dec 5, 2011)

MikeHag said:


> At least she didn't ask if you thought SHE was getting fat
> 
> 
> 
> ...


Hahaha, you make a good point.

After experimenting with the grind and grounds amount (just by eye, no scales yet) this morning I have come out with a much better shot. The crema is darker and thicker and lasts longer and there is a much more distinct nutty-ness to the aroma and taste. There is still a sourness to the shot but this almost vanishes when made into a coffee drink.

I still think the temperature is off, I will find out for sure when my thermometer arrives from ebay (99p by the way, crazy chinese) and there may be a new machine in order for next year, but I'm getting a decent shot now that is a pleasure to drink









p.s. on a side note, I never realised how cool the recommended milk temp is, heated it up to the red spot on my thermometer yesterday and was surprised to have it just above warm. Iv'e always drunk my latte's not hot enough to burn your tongue but hot enough to warm your belly


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## MikeHag (Mar 13, 2011)

Suggest sticking probein a tub of iced water for 5 mins to ensure it reads zero. If not just turn the knut under the dial.


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## gaggiamanualservice.com (Dec 22, 2009)

hi, max temp you will probably get from cubika is 75 to 80 degree, the size of boiler inhibits due to sucking cold in as you brew. changing for new stats will up the temp definately

mark


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## Dylan (Dec 5, 2011)

Hi there, thanks for that, confirms my need for a new machine! lol.

What does "changing for new stats" mean? Am I being a total Noob here?


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