# Homemade Temperature Gauge (Scase Style)



## Xpenno (Nov 12, 2012)

So I wanted to check the offset of my PID on my machine and have been thinking about the best way to achieve this without spending hundreds of pounds on a Scase.

Turns out that this is very achievable for next to no cash and even less skill









One thermocouple thing (eBay Link) or similar.

One standard basket (similar to whatever you use).

One Bottomless Portafilter which you've probably already got.

I'll post a couple of more detailed pics tomorrow but essentially you drill a small hole in the middle of the basket. Poke the thermocouple through and bend it at an angle so that it's at about 45 deg to vertical. Put the basket in the portafilter and plug the thermocouple in. That's it! Now just dose up as usual and brew a shot.

The reason that I decided to make it like this is because I believe that this is a better reflection of the puck temperature and not just the water coming from the group which would be the case when using a blanking plate and 9bar valve like the scase. Whether or not this is technically 'better' I don't know but it's certainly improved shots since making the change.

Here are a couple of pics I took whilst testing, I'll do some more detailed ones tomorrow.



















The temperature gauge was £20 all in, you can get it cheaper from overseas but I opted for a UK seller. It arrived next day! I already had the spare basket and the naked filter so all in all it was a bargain.

Hopefully useful to someone.

Cheers

Spence


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## coffeechap (Apr 5, 2012)

Nice job spence, love seeing home mods like this


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## Xpenno (Nov 12, 2012)

Ok I took a couple more pics..




























Also for this specific temperature monitor I used a 2mm drill bit to give me a nice tight fit.


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## The Systemic Kid (Nov 23, 2012)

Nice one Spence - what were the results temp-wise?


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## Xpenno (Nov 12, 2012)

Still more testing to do over the weekend but it looked to be about 6 degrees out! Which is good news as is been getting some quite thin tasteless shots, especially with lighter roosts, hence me wanting to test it. I did a quick calibration in the kettle and it all looks to be working OK.


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## hotmetal (Oct 31, 2013)

I love the simplicity of this! Plus it really is cheap and simple. Also an interesting point you raise about measuring the temperature of an actual shot as opposed to water.

I'm working on the assumption that the offset on the R58 is about 13-14° but if I ever get curious enough to actually want to check I'll remember this thread.


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## ronsil (Mar 8, 2012)

I like that meter. I use a Victor 86B multimeter but your one looks better.

The AVG/MAX/MIN reading could be very useful. Does this button on the one you linked to work? On one meter I saw that button had been crossed off the spec.


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## Xpenno (Nov 12, 2012)

Not tried it Ron. I'll check tomorrow and let you know.


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## Xpenno (Nov 12, 2012)

Hi Ron, just to confirm, the min\max\avg functions seem to work on the unit that I purchased


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## drude (Apr 22, 2013)

This is pretty cool. Be interesting to see how the results compare to a Scace. Does anyone on here have one and feel like spending another £15 to see if they were ripped off?


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## gman147 (Jul 7, 2012)

Ha! Good point Drude.

Love the efforts Spence, and if it's accurate you could be on to a winner there. Be interested to see it work with a blank also?


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## Spazbarista (Dec 6, 2011)

Just ordered one for £2.99 from HK


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## 4085 (Nov 23, 2012)

Bbbbbbbbbbbbbbbbb


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## drude (Apr 22, 2013)

The link is in the first post.


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## Xpenno (Nov 12, 2012)

Spazbarista said:


> Just ordered one for £2.99 from HK


Probably exactly the same thing, I prefer dealing with UK sellers and wanted it quick.


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## Xpenno (Nov 12, 2012)

gman147 said:


> Ha! Good point Drude.
> 
> Love the efforts Spence, and if it's accurate you could be on to a winner there. Be interested to see it work with a blank also?


Blanking plate makes no sense to me as you will only ever get a small amount of water in the plate and any new water will just be expelled via the opv hence you won't get a true reflection of the temp during a brew. The scase has a 9bar valve to simulate a puck. This doesn't take into account the energy required to raise the temp of the coffee to 94deg.

I personally think it's more accurate but I'm happy to be proven wrong.

The temp gauge itself is accurate as I tested it in my kettle.


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## Obnic (Jan 14, 2014)

I've ordered kit. Will build next week. Thanks Xpenno. Will be interested to compare offsets for various Vesuvii. DaveC reckoned 13 I think. I believe mine is nearer 10. You seem to get 6.


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## DavecUK (Aug 6, 2013)

Obnic said:


> I've ordered kit. Will build next week. Thanks Xpenno. Will be interested to compare offsets for various Vesuvii. DaveC reckoned 13 I think. I believe mine is nearer 10. You seem to get 6.


The offset is 13, not 10 and certainly not 6!

I have my own scace type device I made about 1 year before a scace came out,...the one thing I learnt when making it nearly 8 years ago, is you got to be very careful how you measure temperature!


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## Xpenno (Nov 12, 2012)

Obnic said:


> I've ordered kit. Will build next week. Thanks Xpenno. Will be interested to compare offsets for various Vesuvii. DaveC reckoned 13 I think. I believe mine is nearer 10. You seem to get 6.


I've not had time this weekend to do the in-depth measurements that I wanted to. Should have time this week to make sure that the settings I'm currently using work and I'll post the results when I have them. I just like being able to measure and test these things myself, after the very quick tests that I did my offset it at 17 instead of 13 that it was at previously and the PID is set to brew at 94deg, my shots this weekend have been out of this world, I'm so happy with the results that I've actually started using the pressure profiling properly today to make some shots. Is it "right" I don't know or care at the moment


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## DavecUK (Aug 6, 2013)

Xpenno said:


> I've not had time this weekend to do the in-depth measurements that I wanted to. Should have time this week to make sure that the settings I'm currently using work and I'll post the results when I have them. I just like being able to measure and test these things myself, after the very quick tests that I did my offset it at 17 instead of 13 that it was at previously and the PID is set to brew at 94deg, my shots this weekend have been out of this world, I'm so happy with the results that I've actually started using the pressure profiling properly today to make some shots. Is it "right" I don't know or care at the moment


OK well as I "care" in the sense of other people with the same machine. The offset of 13C is correct. If you own a Vesuvius and set the offset to 17C (not 13C), then at a displayed temp of 94, you will have brew water at pretty much 98C. This in itself is not a problem, if you like your brew water temperature to be 98C. it also gives you the option to consider cooler brew temps and slightly darker coffees, where a high brew temp would make them taste quite poor.


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## "coffee 4/1" (Sep 1, 2014)

i gave it a go, try anything twice, something went wonky the coffee traveled through the inner temperature cable out the multimeter haha, never had a cup there


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## Xpenno (Nov 12, 2012)

\ said:


> i gave it a go, try anything twice, something went wonky the coffee traveled through the inner temperature cable out the multimeter haha, never had a cup there


Lol, I wrapped the lead around my Portafilter handle after this happened to me the first time luckily just with water.


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## "coffee 4/1" (Sep 1, 2014)

laugh, you was waiting that.


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## Xpenno (Nov 12, 2012)

Let me just clear something up, I didn't start this thread to discuss my settings/findings, I'm not trying to start a Vesuvius PID Offset Revolution. This thread is about building a device that can be used to do something similar to a scase and possibly save yourself £300. How you decide to use said device or the results that you get with it is completely up to you.


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## "coffee 4/1" (Sep 1, 2014)

hold up just trying it mate,i work round it to get a result.


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## emin-j (Dec 10, 2011)

Would this work by putting the sensor cable up the spout of normal portafilter?


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## Xpenno (Nov 12, 2012)

emin-j said:


> Would this work by putting the sensor cable up the spout of normal portafilter?


Depends what you are trying to measure but the cable fits up inside my portafilter. I did a quick measure using my standard portafilter today and it's a bit warmer inside that the bottomless. Currently running the offset at 15.5. Still more time required to refine the testing process, need a straight few hours to get stuck in. Maybe Saturday....


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## Firochromis (Oct 26, 2014)

This is a great idea. I just ordered the item. Thank you Xpenno


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## ronsil (Mar 8, 2012)

Can confirm the idea is excellent. I purchased the same instrument from Amazon.

However I have found it to be inaccurate. Held in a kettle in rapidly boiling water it never goes above 97C indicating a 3C error,

The instructions show how to calibrate but are in 'poor' English. Have tried half dozen times but find I have to go back to 'Factory Reset' because the 'instructions' lose me


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## Nikko (Aug 20, 2014)

The boiling temperature of water depends on atmosperic pressure. If the pressure was 0.913 bar, then water would have boiled at 97C


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## ronsil (Mar 8, 2012)

However I also have a 'certified' thermometer which indicated 100C in the same boiling water.


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## Krax (Oct 26, 2014)

I have seen very expensive test equipment damaged in industry for the very same reason. Moisture is forced up the inside of the outer protective sheath. The trick is either to split the sheath at a low point prior to the multimeter (and beware the drips), or use a simple twisted pair thermocouple without the outer sheath. Hope this helps.


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## "coffee 4/1" (Sep 1, 2014)

if at first you don't succeed, give up! but there's always one, cheers krax.


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## Drewster (Dec 1, 2013)

Nikko said:


> The boiling temperature of water depends on atmosperic pressure. If the pressure was 0.913 bar, then water would have boiled at 97C


Errrrrrr would that be at about 900m above sea level?

Does ronsil live near the top of Great Gable.


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## Obnic (Jan 14, 2014)

Tested mine today in boiling kettle showed 98.6c. Met office shows low pressure over UK today with c1000mb isobar over london. Not sure what to think?


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## DavecUK (Aug 6, 2013)

Obnic said:


> Tested mine today in boiling kettle showed 98.6c. Met office shows low pressure over UK today with c1000mb isobar over london. Not sure what to think?


Think about what I said...the offset of 13C is correct.


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## Obnic (Jan 14, 2014)

DavecUK said:


> Think about what I said...the offset of 13C is correct.


Humour me Dave. I'm certainly not as expert as you. You seem adamant that the offset will be the same for all machines which I find a bit counter intuitive for something that is virtually coach built.

Add to this my own experience of some pretty awfully under-extracted shots that seemed to improve with higher temperature; and my experience that your recommended brew boiler PID settings caused consistent overshooting according to the temp readout on my display (now fixed). All of this led me to the theory that apparent and actual temperature are not in line.

So here I am (since I can't borrow a SCACE) practicing that honourable forum art of amateur fettling.

Let me tax your patience once again - teach me.


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## Obnic (Jan 14, 2014)

Obnic said:


> Tested mine today in boiling kettle showed 98.6c. Met office shows low pressure over UK today with c1000mb isobar over london. Not sure what to think?


Received a good pointer - the kettle was not boiling distiller water but rather tap water with c250ppm hardness. May account for difference.


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## garydyke1 (Mar 9, 2011)

even if water boils below 100c. 93c is still 93c lol


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## jeebsy (May 5, 2013)

Obnic said:


> Humour me Dave. I'm certainly not as expert as you. You seem adamant that the offset will be the same for all machines which I find a bit counter intuitive for something that is virtually coach built.
> 
> Add to this my own experience of some pretty awfully under-extracted shots that seemed to improve with higher temperature; and my experience that your recommended brew boiler PID settings caused consistent overshooting according to the temp readout on my display (now fixed). All of this led me to the theory that apparent and actual temperature are not in line.
> 
> ...


x2 - if it's the same for all machines why is it user adjustable?


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## DavecUK (Aug 6, 2013)

jeebsy said:


> x2 - if it's the same for all machines why is it user adjustable?


It's a built in parameter on most PIDs, because depending on the design of the machine it can vary. As all Vesuvius have the same boilers, group, thermosyphon size etc.. then the differences from one vesuvius to another will be small. There could be a thermometry difference internally, which might make your machine up 1C greater or lesser than 13....but I wouldn't think any more. The reason you might be having problems with the shots could be that you are used to very hot brew temps and with the specific coffees you drink, then you expect a certain taste and look of extraction. Light roast coffees will never look as good with the extraction and have a specific taste, this can be changed, in some cases quite markedly by much higher brew temps. It's not uncommon to find HX users develop a taste for the 97C extraction.

As I said, this is perfectly OK if that's what you like to drink, it's not like there is any shame in it. My only "teaching" if you like, was to be aware of the temps your using and then perhaps look to slightly darker coffees at lower temps...See how you like those, because of course darker roasted coffees at very high brew temps, don't taste good at all. In a roundabout way, I'm trying to say look upon this as an opportunity. Or you can simply take the blue pill.

Oh your water if not distilled then the impurities usually raise the boiling point (e.g. making the difference even bigger).....although the effect is going to be marginal.


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## emin-j (Dec 10, 2011)

A couple of questions xpenno,

My meter arrived today ?

Looking at your photos the temp probe would be buried in the coffee puck is that correct ?

Was it your plan to know the temperature of the puck or the brew water ? If the brew water then the probe would need to be above the level of the coffee ?


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## Xpenno (Nov 12, 2012)

emin-j said:


> A couple of questions xpenno,
> 
> My meter arrived today ?
> 
> ...


Temp of the puck was my intention. If you had a saucepan of boiling water and you chucked in some cold pasta it would stop boiling as the pasta absorbs the energy from the water. My thinking was that if coffee extracts best at 94c (yes I know that this is not a fixed number, just using as an example) then surely the coffee with water should be 94c during the reaction not just the water going into the cold coffee.

Not sure mine probe/meter are still playing ball tbh, in the kettle it's not going above 97 now, was pretty much bang on before. Hmm, might have been better spending a little more than £15 but never mind.


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## jeebsy (May 5, 2013)

Xpenno said:


> My thinking was that if coffee extracts best at 94c (yes I know that this is not a fixed number, just using as an example) then surely the coffee with water should be 94c during the reaction not just the water going into the cold coffee.


Do we know if the puck should actually be 93/94 or could it be the 94 was the ideal water temp and the puck would actually be lower?


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## Xpenno (Nov 12, 2012)

jeebsy said:


> Do we know if the puck should actually be 93/94 or could it be the 94 was the ideal water temp and the puck would actually be lower?


No idea mate, that's what I was hoping to find out


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## emin-j (Dec 10, 2011)

Thanks for your reply xpenno, I would like to know in the first instance what the temperature of the water is above the coffee after waiting say 30 seconds after the cooling flush or how long it takes to reach the ideal temp.

I tested my meter tonight placing the probe in the kettle and when the kettle knocked off the meter was reading 99° .


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## Xpenno (Nov 12, 2012)

emin-j said:


> Thanks for your reply xpenno, I would like to know in the first instance what the temperature of the water is above the coffee after waiting say 30 seconds after the cooling flush or how long it takes to reach the ideal temp.
> 
> I tested my meter tonight placing the probe in the kettle and when the kettle knocked off the meter was reading 99° .


Exactly, it's a tool and you can use it however you want


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## Obnic (Jan 14, 2014)

Xpenno said:


> Hmm, might have been better spending a little more than £15 but never mind.


ha ha. Yes. Similar experience here. Still was worth a go. May boil some deionised water just to see if I can get 100c.

Didn't some chap on here say the answer's 13 anyway....


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## Xpenno (Nov 12, 2012)

Obnic said:


> ha ha. Yes. Similar experience here. Still was worth a go. May boil some deionised water just to see if I can get 100c.
> 
> Didn't some chap on here say the answer's 13 anyway....


Dunno, must have missed that









I'd love to know more about the device and process used to get to 13. I absolutely believe that Dave gets 13 I have no reason not to believe that my machine wont work perfectly set to 13. My mind is inquisitive and I like to see what's going on and try to understand for myself. Sometimes someone simply telling you what's right doesn't do cut it.

Dave, I'd love to know more about your procedure and the device used please give share some info with us?


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## TheEspressoNistic (Nov 11, 2014)

To the OP, Is that the Vesuvius??

Nice setup!

Anyways, how does the pressure profilling affect the brew quality...

And also, I've never modded a pf... to that extent, the only mod i did was the "bottoms off" mod and the pf gauge mod (for adjusting OPV)


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## ronsil (Mar 8, 2012)

I liked the look of the meter & purchased one from Amazon, £18.

As soon as I saw how inaccurate it was for the purpose I returned it for a full refund.

I'm back with my Victor 86B that I have used for roasting & logging in the past.

Also after inserting the TC through a tight fitting hole made in a PF Basket & then filling with coffee, under pressure the TC wire can & did blow out of the hole. Still finding bits of debris everywhere on the Vesuvius.

With a good meter the idea is useful to check water delivery temperature out of the group head.


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## Jim bean (Aug 16, 2014)

Nice simple idea mine exploded out the the bottom after a couple of uses too I think it would be a good idea to secure the thermocouple with a spot of heat resistant epoxy

using a teflon coated thermocouple would also stop the water leaching up the sheath

the meter calibration instruction aren't the easiest to follow

press and hold power and c/f/k button

wait for USE2 to disappear

meter will display temp with T1 and wireless symbol in top corner this is for setting temp to 0c

use ice test

use HOLD for temp +

use T1/T2 button on the left for temp -

press T1/T2 button on the right to set

meter will display temp again now with T2 and wireless symbol in top corner this is setting temp to 100c

use boiling water test

use HOLD for temp +

use T1/T2 button on the left for temp -

use T1/T2 button on the right to set

that's it calibrated

cheers James


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## ronsil (Mar 8, 2012)

Translation will be appreciated by those who still have the meter. Many thanks


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## emin-j (Dec 10, 2011)

Blimey exploding thermocouples Bat man ?

I've seen on the net portafilters filled with tin foil rather than coffee to take the temperature of the brew water so to my thinking there wouldn't be the same pressure in the portafilter so maybe avoid explosions etc ? but what affect would this lower pressure have on the meter reading if any .


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## chinery (Apr 14, 2014)

I am by no means qualified to be making bold statements, I'm just repeating what I've heard elsewhere... but I was under the impression that 93/94 degrees is supposed to be the water temp. The colder coffee will bring that down.

In brewed coffee competitions you get people saying they aim for ~80 degrees, measuring the 'slurry' of coffee and water, not the water in the kettle. Of course in an espresso machine you will lose far less temperature.

Still, having a reference point is extremely useful. I might try to rig this up and just use it without the coffee. Even if it's off by a few degrees, it will still give me a point of comparison.


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## Xpenno (Nov 12, 2012)

chinery said:


> I am by no means qualified to be making bold statements, I'm just repeating what I've heard elsewhere... but I was under the impression that 93/94 degrees is supposed to be the water temp. The colder coffee will bring that down.
> 
> In brewed coffee competitions you get people saying they aim for ~80 degrees, measuring the 'slurry' of coffee and water, not the water in the kettle. Of course in an espresso machine you will lose far less temperature.
> 
> Still, having a reference point is extremely useful. I might try to rig this up and just use it without the coffee. Even if it's off by a few degrees, it will still give me a point of comparison.


Thanks for sharing this info, it is certainly a question that it would be good to have a definitive answer on but as you say knowing what temp you are actually running and then adjusting to taste is probably as good as it gets.


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## Obnic (Jan 14, 2014)

Re exploding thermocouples - I used a bit of marine sealant adhesive on the inside of the PF to both seal the wire sleeving and to hold the thermocouple in place. I'm using a single dose basket and it's holding together.

Re measurement - coffee absorbs a lot of heat so, after a few tries, I set a profile to just run at 9bar after some preinfusion and let it run to see what the peak temperature was. In the event I measured 93.5C against a target 95C showing on the Vesuvius display.

Somewhat irritatingly I had an offset setting of 11.5C which would lend credence to DaveC's 13C recommendation. Only problem is that I have no idea whether the meter is measuring temperature accurately. How on earth does one reliably and accurately calibrate the thermocouple?


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## Xpenno (Nov 12, 2012)

TheEspressoNistic said:


> To the OP, Is that the Vesuvius??
> 
> Nice setup!
> 
> ...


Yes it is mate, awesome machine 









Pressure greatly affects the taste of the resulting shot in my tests.


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## garydyke1 (Mar 9, 2011)

jeebsy said:


> Do we know if the puck should actually be 93/94 or could it be the 94 was the ideal water temp and the puck would actually be lower?


SCACE doesnt use a bed of coffee. Its to measure water temp exiting the group, e.g UKBC machines SCACE'd to 93.5C. The temperature usually starts lowish then increases then settles and stays constant, its the constant end temp you're looking for.

It you're measuring puck temp at which point of the extraction are you measuring ? This will vary based on dose and coffee bed depth.

Measure the water and nowt else


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## DavecUK (Aug 6, 2013)

Read this, I posted it for boots. I cover temperature testing on in the 2nd of my posts.

http://vesuvius.freeforums.org/post406.html#p406


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## Xpenno (Nov 12, 2012)

garydyke1 said:


> SCACE doesnt use a bed of coffee. Its to measure water temp exiting the group, e.g UKBC machines SCACE'd to 93.5C. The temperature usually starts lowish then increases then settles and stays constant, its the constant end temp you're looking for.
> 
> It you're measuring puck temp at which point of the extraction are you measuring ? This will vary based on dose and coffee bed depth.
> 
> Measure the water and nowt else


Thanks for the info, exactly what I was looking for!


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## chinery (Apr 14, 2014)

Just an FYI to anyone else thinking of buying one... I ordered one off the eBay link in the original post, there are some for a few quid cheaper on eBay but they all seem to quote 10+ days for delivery. Not in a particular rush but happy to pay an extra £2-3. However I got a message today saying that they weren't happy with the quality so are waiting on their supplier or some nonsense? I assume they just ran out of UK stock and are just planning to fulfil orders when the new shipment arrives.

Anyway I asked for a refund and bought one off amazon instead.

I have one of those Bonavita kettles that shows the temperature, which I trust to be accurate enough. So when it arrives I'll stick the probe in there and see what the disparity is, and report back.


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## emin-j (Dec 10, 2011)

Had a play with mine yesterday and was quite an interesting exercise , I drilled a hole in the side of the basket so the probe would be close to the top of the puck and sealed around the hole with blu tac

I was then able to fill the basket as normal and tamp then just lift the probe to the surface of the puck.

After a 30 min warm up I removed the portafilter and did a cooling flush as I normally do then placed the portafilter back in position and set my timer for 30 seconds then at the beep pulled the shot









No exploding thermocouples !

The water did run much quicker than a normal shot probably escaping through the hole I drilled but I was able to see a steady temperature for a couple of seconds of 94° at 45 seconds after a cooling flush it showed 95.2° . As the meter showed 99° at boiling point in the kettle I suppose I could add 1° to those figures but I am happy with the results as it gives me something to work with, thanks xpenno:good:

Ps the reading showing on the meter was with the machine warming up.


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## Xpenno (Nov 12, 2012)

emin-j said:


> Had a play with mine yesterday and was quite an interesting exercise , I drilled a hole in the side of the basket so the probe would be close to the top of the puck and sealed around the hole with blu tac
> 
> I was then able to fill the basket as normal and tamp then just lift the probe to the surface of the puck.
> 
> ...


Good stuff









I found that after calibrating with boiling water (as per the instructions posted earlier in this thread) I was hitting the sort of figures I was expect and have returned the offset back to 13 as per Dave's results. Not sure about how to calibrate the 0c reading as I have no reason to believe that ice from the freezer would be at 0 and would probably quite a bit lower, still, the upper range seems good. Should be a useful little tool going forward


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