# New Lelit Bianca Water Temp Accuracy (Bad)



## Mattjkilo (Apr 13, 2019)

Recently bought a new Lelit Bianca and I was curious as to how accurate the water temperature from the group head was compared to PID setting.

In short it didn't go well. In a plastic cup that had been pre-warmed with kettle water (100C) the temperature from the group head was measuring at 83C. The PID was set to 93. Huge difference!

Is something wrong here? Thermometer is accurate to with 0.5C.


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## Mrboots2u (May 10, 2013)

Mattjkilo said:


> Recently bought a new Lelit Bianca and I was curious as to how accurate the water temperature from the group head was compared to PID setting.
> 
> In short it didn't go well. In a plastic cup that had been pre-warmed with kettle water (100C) the temperature from the group head was measuring at 83C. The PID was set to 93. Huge difference!
> 
> Is something wrong here? Thermometer is accurate to with 0.5C.


 it will not be 93 c from any machine , measured this way. nor should it be

if you want to measure temp, you need a scace like device.

there is nothing wrong with your machine.


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## Rob1 (Apr 9, 2015)

No there's nothing wrong. You measured the temp of the water in the cup not the group head itself right? As in "the temperature from the group head" means 'the temperature of the water that had come from the group head and was in the cup'?

You'll lose a lot of heat at it drops out of the group and lands in the cup and then the cup with further absorb heat.


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## lake_m (Feb 4, 2017)

Most PID machines have an offset. This increases the boiler temp by a set amount so that the temperature at the group head actually measures what the boiler temperature is set to. It's normally factory set so no need to fiddle with it.


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## MediumRoastSteam (Jul 7, 2015)

Disappointing to see how some users have to first say that there's something wrong with their machine because the methodology and rationale used to problem solve is assumed to be right. Why not ask differently, always assuming there's a gap in their methodology and knowledge first?


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## Michael87 (Sep 20, 2019)

lake_m said:


> Most PID machines have an offset. This increases the boiler temp by a set amount so that the temperature at the group head actually measures what the boiler temperature is set to. It's normally factory set so no need to fiddle with it.


 Wouldn't the offset be applied to the temperature displayed too? Eg 93degC on the screen with 10degC offset means the boiler is at 103degC and the group is approximately 93?

So that wouldn't explain why the water in the cup is 83degC.


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## lake_m (Feb 4, 2017)

Depends what your actual off-set is set to. Mine for example on the La Spaziale was set to +5*C. Which meant the boiler was actual aiming for 98*c to get 93*c at the group. My LM also has an off-set but I haven't even looked at it. It may be worth checking to see if there has been one set at the factory, because if it's set to zero then there will likely be a drop from what the set point of the boiler is. But as others have said unless you have a Scace or something similar you'll not get an accurate reading using a cup.


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## ajohn (Sep 23, 2017)

A review on a machine by one of the engineers that designs them mentioned that they aim for around 80C in the cup. It's also loosely speaking the temperature the portafilter should get to if left in machine with a heated grouphead to warm up.

Both are a bit subjective because of ambient temperature so don't get too excited if they are off these figures. The main aim is to get the coffee grounds brewed at a sensible temperature. Measuring that needs some rather specialised equipment.

John

-


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## Nikko (Aug 20, 2014)

An approximate way to check the temperature is to increase the set point to a degree or two above 100C, then run some water which should flash to steam. The e61 loses 10 to 15C so the offset needs to take that into account


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## Mattjkilo (Apr 13, 2019)

MediumRoastSteam said:


> Disappointing to see how some users have to first say that there's something wrong with their machine because the methodology and rationale used to problem solve is assumed to be right. Why not ask differently, always assuming there's a gap in their methodology and knowledge first?


 You seem to be mistaken good sir - I have asked the question "is something wrong here?" not made a statement.

My methodology had actually made an effort to take into account temp fall by over heating the very vessel the water was landing into.

It's actually more disappointing that 'some users' make more of an effort to denigrate others rather than providing constructive support/feedback.


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## Mattjkilo (Apr 13, 2019)

lake_m said:


> Depends what your actual off-set is set to. Mine for example on the La Spaziale was set to +5*C. Which meant the boiler was actual aiming for 98*c to get 93*c at the group. My LM also has an off-set but I haven't even looked at it. It may be worth checking to see if there has been one set at the factory, because if it's set to zero then there will likely be a drop from what the set point of the boiler is. But as others have said unless you have a Scace or something similar you'll not get an accurate reading using a cup.


 Really helpful thankyou!


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## Mattjkilo (Apr 13, 2019)

ajohn said:


> A review on a machine by one of the engineers that designs them mentioned that they aim for around 80C in the cup. It's also loosely speaking the temperature the portafilter should get to if left in machine with a heated grouphead to warm up.
> 
> Both are a bit subjective because of ambient temperature so don't get too excited if they are off these figures. The main aim is to get the coffee grounds brewed at a sensible temperature. Measuring that needs some rather specialised equipment.
> 
> ...


 Got it, thanks John. Most helpful.


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## DavecUK (Aug 6, 2013)

I extensively reviewed the prototype for Lelit and Bella Barista. This included 5 days of temperature testing on my equipment. I believe Lelit made my settings the default, certainly the BB user guide has my recommended settings. The brew temp is very accurate over a wide range...at the correct flow rates.


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## Mattjkilo (Apr 13, 2019)

DavecUK said:


> I extensively reviewed the prototype for Lelit and Bella Barista. This included 5 days of temperature testing on my equipment. I believe Lelit made my settings the default, certainly the BB user guide has my recommended settings. The brew temp is very accurate over a wide range...at the correct flow rates.


 Thanks Dave, I shall check when back from work. From your experience does water temp (in cup) vary much from the 93. I appreciate variables exist but in a cup that was hotter than 93 I assumed it would be close (not 83) unless I'm otherwise mistaken?


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## lake_m (Feb 4, 2017)

I checked my set up a couple of years ago with this cheap K-type thermocouple fed through into portafilter. I used a rubber stopper with enough of a gap to let some flow through to mimic a genuine flow. if you're hell bent on checking, this will give you more accuracy than a cup.


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## DavecUK (Aug 6, 2013)

Mattjkilo said:


> Thanks Dave, I shall check when back from work. From your experience does water temp (in cup) vary much from the 93. I appreciate variables exist but in a cup that was hotter than 93 I assumed it would be close (not 83) unless I'm otherwise mistaken?


 Your mistaken, *if your machine is set as in the Bella Barista user guide* then it will be fine


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## MediumRoastSteam (Jul 7, 2015)

Mattjkilo said:


> You seem to be mistaken good sir - I have asked the question "is something wrong here?" not made a statement.
> 
> My methodology had actually made an effort to take into account temp fall by over heating the very vessel the water was landing into.
> 
> It's actually more disappointing that 'some users' make more of an effort to denigrate others rather than providing constructive support/feedback.


No worries. Bad start of the day for me I suppose. Apologies. I was mainly focusing on the title of the thread, which by reading it implies that the temp accuracy on the machine is bad. On a paragraph, you also say "It didn't go well".

Regardless, when I had a fancy espresso machine the offset was 15C. They means that, for the temperature in the group to be 94C, the temp in the boiler would need to be 109C.

If the temp if he water coming out of the group is 83C your shots should be incredibly sour (not to be confused with bitter). Are they? How do they taste?

And, if you then increase the temperature by 10C - to be 93C "in the cup" (presumably 103 in the display) using your methodology what do you get? If the current temp is 93C in the display and yielding good tasting shots, I'd expect to see steam / flashing boiler water coming out of the group and your shots to taste bitter/burnt.

Good luck and let us know how it goes.


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## Mattjkilo (Apr 13, 2019)

MediumRoastSteam said:


> No worries. Bad start of the day for me I suppose. Apologies. I was mainly focusing on the title of the thread, which by reading it implies that the temp accuracy on the machine is bad. On a paragraph, you also say "It didn't go well".
> 
> Regardless, when I had a fancy espresso machine the offset was 15C. They means that, for the temperature in the group to be 94C, the temp in the boiler would need to be 109C.
> 
> ...


 To be truthful you raised a valid point! I'll take extra care in future! ?

ps - I'm already re-appraising my approach and will gladly report!


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## Rob1 (Apr 9, 2015)

Mattjkilo said:


> To be truthful you raised a valid point! I'll take extra care in future! ?
> 
> ps - I'm already re-appraising my approach and will gladly report!


 Have you measured the temp of your cup? Because I'll be amazed if you managed to get it above 93c by pouring water into it from a kettle and then emptying it before pulling water from the group. The water will cool rapidly as it leaves the kettle and then continue to cool in the cup...and then when the cup is empty there's a huge surface area for further loss.

The water falls from the group in droplets and cools rapidly. Typically it'll be low to mid 80s in the cup for a set temp at the group of 90-95c. You can get a thermometer that goes into the hex bolt on the group to measure the water temperature as it is pushed out of the group if you want but they are really meant for HX machines rather than PID DBs.


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## Mattjkilo (Apr 13, 2019)

Rob1 said:


> Have you measured the temp of your cup? Because I'll be amazed if you managed to get it above 93c by pouring water into it from a kettle and then emptying it before pulling water from the group. The water will cool rapidly as it leaves the kettle and then continue to cool in the cup...and then when the cup is empty there's a huge surface area for further loss.
> 
> The water falls from the group in droplets and cools rapidly. Typically it'll be low to mid 80s in the cup for a set temp at the group of 90-95c. You can get a thermometer that goes into the hex bolt on the group to measure the water temperature as it is pushed out of the group if you want but they are really meant for HX machines rather than PID DBs.


 I went through 4 iterations of heating the cup with 100C water (each time re-boiling the water) and used a cup with a high thermal mass also. I had left the digital thermometer (instant read from Thermapen) in the cup between heating cycles also to ensure this hadn't accounted for any heat loss also. I didn't go for a 5th as the temp of the water had remained stable enough to assume the cup was hotter than 93.

I had taken into account the heat loss due to droplets but assumed it wouldn't be as high as originally found. Perhaps this assumption was the one which was ill founded!


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## MediumRoastSteam (Jul 7, 2015)

Mattjkilo said:


> I went through 4 iterations of heating the cup with 100C water (each time re-boiling the water) and used a cup with a high thermal mass also. I had left the digital thermometer (instant read from Thermapen) in the cup between heating cycles also to ensure this hadn't accounted for any heat loss also.
> I had taken into account the heat loss due to droplets but assumed it wouldn't be as high as originally found. Perhaps this assumption was the one which was ill founded!


What if you do your test with water from the kettle as soon as it clicks off instead of water from your coffee machine? What reading do you get? That will give you an indication of heat lost to the vessel and should help calibrate your experiment.


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## Mrboots2u (May 10, 2013)

DavecUK said:


> Your mistaken, *if your machine is set as in the Bella Barista user guide* then it will be fine


 this..


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## PPapa (Oct 24, 2015)

DavecUK said:


> I extensively reviewed the prototype for Lelit and Bella Barista. This included 5 days of temperature testing on my equipment.


Could you share the equipment and test procedure being used?


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