# How do we temperature surf with a Gaggia Classic? Does it matter with less shots?



## ShaunChris

Hi guys,

Just bought a used, descaled Gaggia Classic with the OPV 10 bar mod and a Silvia wand. No PID unfortunately. I've read that the Gaggia Classic has some problems with temperature surfing, so I went to read up and do my research, but I still have some questions:

1.) I've read that a common method to temp surf the Gaggia Classic is to switch on the machine for at least 30 minutes to preheat it. Thereafter, switch on the pump, and wait for the light to switch*off*. At this point of time, light = off means that the temperature is too low, so the heating elements will be kicking in.

Then wait until the light comes on, and immediately pull the shot. Does that sound reasonably like the correct thing to do?

2.) Does this matter if I'm only pulling one shot? I heard that PID-ing solves the temperature surfing problem - And that PID-ing solves *inter-shot* temperature stability, but not *intra-shot* stability. Considering most of the time, I will either be pulling a double espresso, or *two* double espressos, tops, is temperature surfing that important?

3.) Is there anything else I need to know about temp surfing? I only have a Hario Mini Mill and the Gaggia Classic, and don't really have much time in the mornings to stand around waiting for the lights to switch on or off, so if temperature surfing is not 100% required, then I wouldn't mind learning it, but I would most likely not do it 100% of the time because I'm in a rush most of the time. The 30 minute preheat warm up isn't a problem because I can set that up with an electronic programmable plug, but the waiting around might be.


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## jimgrant

Hi there, not sure about the temp surfing, I leave gaggia on for 10 mins pull some water into cup then dry the portafilter , then dose, purge some water through then insert portafilter and pull shot. Not sure you can control the temp greatly on this machine but still gets good coffee.


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## marcuswar

Its not about controlling the temperature so much as just starting from a known point every time which equates to more consistency between shots. Without using the temperature surf routine you will be puling shots at different starting temperatures dependant upon where the Gaggia is up to in it cycle. This leads to differences in taste between shots.

You can influence the temperature slightly by flicking the steam switch on for a few seconds once the Gaggia is at the top of heating cycle just before you pull the shot. By varying the number of seconds you leave the steam switch on you can vary the starting temperature of the shot.

When I used my Classic I always used temp surfing and would always flick the steam switch 6 seconds before pulling the shot as I found it gave me a better (less sour) shot.


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## jimgrant

Cheers for reply,will give it a try tomorrow.


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## urbanbumpkin

ShaunChris said:


> Hi guys,
> 
> Just bought a used, descaled Gaggia Classic with the OPV 10 bar mod and a Silvia wand. No PID unfortunately. I've read that the Gaggia Classic has some problems with temperature surfing, so I went to read up and do my research, but I still have some questions:
> 
> 1.) I've read that a common method to temp surf the Gaggia Classic is to switch on the machine for at least 30 minutes to preheat it. Thereafter, switch on the pump, and wait for the light to switch*off*. At this point of time, light = off means that the temperature is too low, so the heating elements will be kicking in.
> 
> Then wait until the light comes on, and immediately pull the shot. Does that sound reasonably like the correct thing to do?
> 
> 2.) Does this matter if I'm only pulling one shot? I heard that PID-ing solves the temperature surfing problem - And that PID-ing solves *inter-shot* temperature stability, but not *intra-shot* stability. Considering most of the time, I will either be pulling a double espresso, or *two* double espressos, tops, is temperature surfing that important?
> 
> 3.) Is there anything else I need to know about temp surfing? I only have a Hario Mini Mill and the Gaggia Classic, and don't really have much time in the mornings to stand around waiting for the lights to switch on or off, so if temperature surfing is not 100% required, then I wouldn't mind learning it, but I would most likely not do it 100% of the time because I'm in a rush most of the time. The 30 minute preheat warm up isn't a problem because I can set that up with an electronic programmable plug, but the waiting around might be.


Hi Shaun

I used to use option 1) flush about 1oz of water thought the group. Light will eventually go off. Lock PF, wait till light goes on pull shot immediately.

Seemed to work for me with the Classic.

I never did the steam thing but I didn't have a PID.


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## Jari

ShaunChris said:


> Hi guys,
> 
> Just bought a used, descaled Gaggia Classic with the OPV 10 bar mod and a Silvia wand. No PID unfortunately. I've read that the Gaggia Classic has some problems with temperature surfing, so I went to read up and do my research, but I still have some questions:
> 
> 1.) I've read that a common method to temp surf the Gaggia Classic is to switch on the machine for at least 30 minutes to preheat it. Thereafter, switch on the pump, and wait for the light to switch*off*. At this point of time, light = off means that the temperature is too low, so the heating elements will be kicking in.
> 
> Then wait until the light comes on, and immediately pull the shot. Does that sound reasonably like the correct thing to do?
> 
> 2.) Does this matter if I'm only pulling one shot? I heard that PID-ing solves the temperature surfing problem - And that PID-ing solves *inter-shot* temperature stability, but not *intra-shot* stability. Considering most of the time, I will either be pulling a double espresso, or *two* double espressos, tops, is temperature surfing that important?
> 
> 3.) Is there anything else I need to know about temp surfing? I only have a Hario Mini Mill and the Gaggia Classic, and don't really have much time in the mornings to stand around waiting for the lights to switch on or off, so if temperature surfing is not 100% required, then I wouldn't mind learning it, but I would most likely not do it 100% of the time because I'm in a rush most of the time. The 30 minute preheat warm up isn't a problem because I can set that up with an electronic programmable plug, but the waiting around might be.


thread resurrection attempt. I'm in exactly this situation - very succinctly summarised by @ShaunChris btw - & was wondering if anyone can shed more light on the matter? am basically after tips for the dark art of temp surfing, so any suggestions gratefully received.


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## les24preludes

urbanbumpkin said:


> I used to use option 1) flush about 1oz of water thought the group. Light will eventually go off. Lock PF, wait till light goes on pull shot immediately.
> 
> .


I'm trying to get a routine together - agree with previous post that it's about getting the start temperature right. But when the light comes back on I find I wait more like 30 seconds or even more. Someone else said 25 seconds. I read the light comes on at 95* and goes off at 105*. Still trying to work this out, but it seems to me that it needs to be hotter. I'm going to get a thermocouple and do some measuring. Everyone says get a PID but I just pull single shots of around 30ml and it seems to me that if you get the start temperature right that's most of what's needed.


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## Kitkat

I run some water through so that the light goes off and then get my cup and scales underneath in time to press the button as soon as the light goes on again. My aim at this stage is merely to try and get the same temperature each time. So that would be pulling the shot when the temperature is at it's highest? I have heard that the hotter temperature results in more extraction and a shot with sweeter, fuller flavour. I haven't yet fully investigated the effect of temperature on flavour and am just trying to ensure consistency at this point. I let my Classic heat up for about half an hour before I use it.


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## urbanbumpkin

The classic does have a big temp swing. Might be worth getting a PID.


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## ashcroc

urbanbumpkin said:


> The classic does have a big temp swing. Might be worth getting a PID.


Having seen one in action, I couldn't agree more.


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## Monkey

How are the temperatures mentioned above being measured? Just curious. I like the idea of a PID but havent got round to it yet.


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## ashcroc

Monkey said:


> How are the temperatures mentioned above being measured? Just curious. I like the idea of a PID but havent got round to it yet.


Someone somewhere will have measured the temperatures the stock stats react at.


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## Monkey

ashcroc said:


> Someone somewhere will have measured the temperatures the stock stats react at.


I obviously missed the bit where it says "i read".


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## ashcroc

Monkey said:


> I obviously missed the bit where it says "i read".


That's easily done. 

The 20° swing is huge for coffee making purposes hence the need to temp surf or fit a PID to remove it. Some peeps have even gone as far as fitting a preheat coil too to try & combat the temp drop from the small boiler.


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## les24preludes

ashcroc said:


> Someone somewhere will have measured the temperatures the stock stats react at.


Can't remember the source but I read the red light comes on at 95* and goes out at 105*. So it seems to me that the cue to start the pour is the red light going out = 105*. Attached graph showing that boiler 105* gives 95* in the PF. See https://www.home-barista.com/tips/different-approach-to-gaggia-temperature-routine-t22059.html

My revised 'quick and dirty' routine is therefore:

- Turn machine on, purge and clean screen

- Fill PF with coffee

- Heat machine with PF in it

- Heat milk externally

- Wait for red light to come on, 95*

- Wait for red light to go off, 105* (? and wait 30 secs).

- Pull shot

The "wait 30 secs" comes from the YT tutorial with the Silvia, so not sure if this applies to the Classic with a smaller boiler.





 According to Gail the boiler is at 95* after 30 sec, but looks from the graph like we want the Classic boiler to be at 105* to allow for the inrush of cold water.


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## Liasis

Hmm, this may have swayed me as well to invest in a PID.


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## Beethovens_Beans

Great thread, thanks for all the info!


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## les24preludes

Just updating my procedure. Based on the graph above, the boiler must be at 105*, at the least, to get 95* in the grinds. The thermostat is rated 107* so that sounds right. I don't preheat the machine - I don't really see what that achieves. I let it heat up until the red light comes on - that's pretty quick. I then play around with the steam switch until the right amount of steam comes out on a brief pour (no PF attached). Visually speaking, there should be a modest amount of steam, but not clouds of steam. If you go too far on the steam switch you get a tell-tale noise of boiling water - that's much too far. But you do need go go a bit beyond the red light. I'm guessing 5 to 10 seconds but still a matter of trial and error. The taste will give you a good idea. This whole procedure is pretty quick, and as far as I can see just as effective as preheating the machine, which gave me no benefits I could see.

Anyway, I'm now getting my best shots, so the above seems to be pretty close. It's all in the kind of steam coming out of the group. Get that right and you're golden.


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## timmyjj21

Preheating can be useful, considering that temperature is measured on the Classic only as the boiler surface temperature right between the element. The boiler may be hot, but the water inside isn't necessarily at the correct temperature with such a short warmup time. The boiler head and the portafilter also need time to equilebrate.

Flicking the steam switch or running through water may speed up the heating time, but may not work well for another Classic user...hence the dark arts of temperature surfing (Just buy a PID!)


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## les24preludes

timmyjj21 said:


> Preheating can be useful, considering that temperature is measured on the Classic only as the boiler surface temperature right between the element. The boiler may be hot, but the water inside isn't necessarily at the correct temperature with such a short warmup time. The boiler head and the portafilter also need time to equilebrate.
> 
> Flicking the steam switch or running through water may speed up the heating time, but may not work well for another Classic user...hence the dark arts of temperature surfing (Just buy a PID!)


The temperature of the water inside the boiler can be judged by the steam coming out of the group - that's the point. The boiler gets hot not by 'warm up' but by flicking the steam switch on, which heats quickly. As far as I can see, all we need to know is the temperature of the water coming out of the group, however it is derived. I agree that there may be some sense in warming the PF but I'm getting my best shots without any need for that. I've taken the twin spouts off my PF so there's just the one hole, so less metal to interfere with the temperature. I realise that there are plenty of routines used by Classic owners. What I'm suggesting is a routine for judging temperature - by the amount of steam on a very quick purge - that's quick and works well. The purge doesn't cool down the water in the boiler - it's too quick for that. It's just a visual indicator.


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## jj-x-ray

Interesting....I'm still unsure of the correct surfing method. I leave my classic on for 20 odd mins, then remove the pf and purge some water into my cup to warm it up. The boiler light goes off, then I reattach the pf full of coffee and pull the shot as soon as the boiler light comes back on.

Never though about playing with the steam switch....


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## les24preludes

jj-x-ray said:


> Interesting....I'm still unsure of the correct surfing method. I leave my classic on for 20 odd mins, then remove the pf and purge some water into my cup to warm it up. The boiler light goes off, then I reattach the pf full of coffee and pull the shot as soon as the boiler light comes back on.
> 
> Never though about playing with the steam switch....


I've only had my Classic for 2 months, so no expert, but in that time I've come to the conclusion that too hot is better than too cold. Without the steam switch I wasn't quite getting it hot enough a lot of the time, so lacklustre pours. When i see a little steam coming out of the group I get fuller, sweeter, hotter pours. So I'd say the steam switch is your friend here and puts you in control.


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## jj-x-ray

I'll have a try this weekend


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## ashcroc

les24preludes said:


> I've only had my Classic for 2 months, so no expert, but in that time I've come to the conclusion that too hot is better than too cold. Without the steam switch I wasn't quite getting it hot enough a lot of the time, so lacklustre pours. When i see a little steam coming out of the group I get fuller, sweeter, hotter pours. So I'd say the steam switch is your friend here and puts you in control.


It could be your brew stat has degraded over time so it shuts off at too low a temp. Replacing it won't stop the need to temp surf (unless you replace it with a PID) soit's uestionable if it's worth doing since you've already found a workaround you're happy with.


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## les24preludes

ashcroc said:


> It could be your brew stat has degraded over time so it shuts off at too low a temp. Replacing it won't stop the need to temp surf (unless you replace it with a PID) soit's uestionable if it's worth doing since you've already found a workaround you're happy with.


Who knows - the thermostat may or may not be accurate as you say. When the red light first comes on there's no visible steam out of the group.

But as you say, I've found a routine that's working very well. Best shots yet. It seems to me that whatever the workings of the thermostat, you still need a little steam coming out of the group so you always have a visual indication of the temperature to help you calculate. You can get used to visual indicators, as you do when watching the brown mouse tails turn yellow in the pour.


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