Shot temperature

Cuir Beluga

Hi all. I'm not sure if I have a problem or not......

Matt pulled a shot earlier this morning and it seemed rather on the cool side. I pulled one and I thought it seemed cooler than normal, 40C.
Hubby suggested a backflush in case there was a blockage, pulled 2 more shots and they seemed normal in temperature. After backflushing the shot came in at 60C.
What sort of temperature would you consider in the normal range?

Thanks, Sue .

Dry_bean.

Around 70°C suits me Sue, are you allowing the machine sufficient time to warm up, normally 15 minutes minimum, 30 minutes is better.

GeekKopi

^^^ agree with above. Also what I do is I bleed any false pressure in the boiler by purging the wand while the machine is warming up. I find that on my vbm around 25 mins warm up is suffice for that e61 group to get to the right temp. I also leave my portafilter locked in the group head while its warming up so the entire path is warm. For my cups I warm them up with water from the hot water outlet. Nothing will cool a coffee quicker than a coldish cup. The cups act like heat sinks and will quickly take the heat from the coffee. I also pull my shots after the boiler element switches off at around 1.25 bar.

Cuir Beluga

Thanks both . I admit that more often than not I use it as soon as it is hot, around 6 minutes, and I haven't had any problems. This time around it had actually been on for some time which is why it threw me that the shot was cooler than normal. The group and everything is hot, steaming is fine, hot water is fine. We have given it a water backflush and have just ran some cafetto through it and it seems ok. I have turned it off and will see how it goes from cold, or almost cold, next cuppa. A silly question but if the flow is too slow would that cool the shot as well? I also had to fiddle with the grinder as I was almost choking the machine. Maybe I am just paranoid  ::).

Brett H

Absolutely Sue.  30 minutes to warm up with the cups on top to warm them too!

FreshCoffee2

Hi Sue, have now returned to the Developed World. Arhhh yes....paranoid !  ; Some background. If you are going to check the brew temp of an espresso machine you need to have a properly calibrated and fast reading instrument, and do it in the correct manner. For most people, that usually means, please dont use the milk thermometer! It does mean, using a specially set up group handle with facility for the calibrated thermocouple positioned inside the "group cup" of the group handle (ie the space where the coffee filter would otherwise live). There would also be an open/shut valve where the coffee outlets usually live, so that flow of hot water can be regulated (or not) through the group handle while the reading is taken. One form of that is a thing called  a "scace" device because it was marketed by someone called  Mr. Scace,  but he doesnt have a monopoly on that kind of gear and we were making them in house for our own workshop use likely before Mr Scace was even born..... ;D OR....there are some thermometers that can be fitted into the group itself and are on permanent display, but we dont use them and dont know how accurate they may be (however my peronal opinion would be that fitting one of those may actually cause paranoia as it allows you to watch *normal* temperarture fluctuations as they come and go, and obscess about whether there is something qrong with a machine or not....I prefer not to sell that stuff to people as it can just cause everyone to look for problems where there usually aren't any...). Others have already advised, to leave your machine on for a minimum time before making coffee. 6 minutes is not long enough, and you probably found that the coffee had a yellow crema. That is a tell tale of under extraction from the brew water being under temp. ADDITION: Further....at 6 minutes the water in the boiler has reached operating temperature and the pressurestat has switched off the element......BUT.....the group itself is still only luke warm. So if you make coffee then, the HOT water coming from the heat exchanger is actually COOLED by the under temp mass of the group (around 3 kg). Ergo: underextracted coffee from undertemp water. Despite that the element has switched off, the machine in toto is not ready to brew, until THE GROUP has also reached operating temperature.  That wouldnt occur until around say 20 minutes in reality, although you can "cheat" the machine into being ready sooner by intermittently flowing water through the group at regular intervals from the point at which the pressurestat first switched off  the element, until you can feel that the group has become too hot to touch. That is quicker than if you just leave the machine to heat passively at its own rate.... and is good for when you are in a hurry (I do it !). Phew..... If you use a well calibrated thermometer and you want a *rough* indication of the temperature of the brew water, note that if you simply stick the end of the (pre warmed, because these thermometers are slow to read and the coffee will be cooling while the needle is rising) thermometer in a (pre warmed) espresso cup while brewing coffee, you can expect to read a coffee temperature in the cup of roughly 70 degrees. That is quite normal. But as I mentioned earlier, its not a great idea to use a milk thermometer because they are not usually very well calibrated and they are slow, and who knows what the reading will show. Ultimately, may I conclude so: a) Machine not on for long enough before coffee was brewed or temp check was done, b) accuracy and type of instrument used suss? c) method of test suss? Nothing to be concerned about, this is a very common concern amongst new machine buyers  Hope that helps, A

Cuir Beluga

Thanks Brett, the cups are always roast toasty when I take them off . Welcome back Attilio and thank you, that all makes perfect sense to me, I must have more patience. You can add another to your list of conclusions D) operator suss  :pan.

GeekKopi

on 1433569027:

Thanks Brett, the cups are always roast toasty when I take them off . Welcome back Attilio and thank you, that all makes perfect sense to me, I must have more patience. You can add another to your list of conclusions D) operator suss  :pan.

Hi Sue I invested in a wifi power switch. I put my machine to the ON position and plug the power lead into one of these. It turns my machine on 30 mins before I wake up. Basically it's a switch, electronic timer (programmable for on and off times) but the beauty is I can switch the machine on/off remotely through my phone (iPhone or android). So if I'm out and I want a coffee for when I get home I can turn it on through my phone so when I get home the machine is warm. I can't live without it. It's the ARLEC WIFI POWER SWITCH. $38 from Bunnings.

Cuir Beluga

Thanks GeekKopi, I'll get hubby to grab one next time he does a Bunnings run. Think I might get one for my leccie blanket too :D. Just to go right off topic is there any sign of your offspring making her way into this world yet?

Brett H

Wonderful post Fresh Coffee...welcome back!

GeekKopi

on 1433586550:

Thanks GeekKopi, I'll get hubby to grab one next time he does a Bunnings run. Think I might get one for my leccie blanket too :D. Just to go right off topic is there any sign of your offspring making her way into this world yet?

Not just yet Sue. But we will be booked in for a c-sec due to the little one being breeched. We had the ECV yesterday with no luck of her turning. I'd say she will arrive in 1.5 to 2 weeks time.

Cuir Beluga

It's getting close then, it is so exciting . Get your sleep while you can. I had 2 c-sections, my first was induced but he wouldn't come out so it was an emergency c-section. My second was a planned one as they said I had almost no chance of getting him out if I couldn't get the first one out because the second one was quite a bit bigger. I did ask if they would let me have a try naturally and they said yes but that it would probably end in a c-section so I went with their recommendations. Thankfully I did, he was 10lb 15oz :D.

Koffee_Kosmo

My answer won't be as long as FCs But may take the liberty to expand and FC may want to confirm ? Coffee machine makers generally calibrate the heat band from 89 to 92 degrees at the boiler The boiler transfers heat by both contact & radiation to the the rest of the machine and also the heat exchanger - A coil of pipe inside the boiler supplied with fresh tank water via the pump The reason the temperature band chosen is because it also correlates to the best temperature to suit roasted beans to second crack This is an important correlation and synergy Unless your machine has an electrically heated group head you need to allow time for all components to reach a good operating temperature Hope my answer helps KK

GeekKopi

on 1433592042:

The reason the temperature band chosen is because it also correlates to the best temperature to suit roasted beans to second crack This is an important correlation and synergy  KK

That's good info KK and explains why I read that some operators calibrate their temp for certain beans so they can obtain better extractions. I've seen some videos on the new rancilio classe 11 temp profiling machine which allows the temp to be varied during the extraction process. Seems like great technology to close the gap between barista and roaster.

Brett H

And then you have machines that vary the pressure also during extraction.  With all these variables one wonders if the end product of some of these machines is not actually coffee!  i.e. load coffee grinds here, press lol the buttons, out comes Fanta!  Oh the notes, notes, notes....  >:D

Cuir Beluga

Thanks KK and very interesting re the second crack temp correlating with the boiler temp. band. Thanks Brett and GeekKopi  .

GeekKopi

on 1433627311:

And then you have machines that vary the pressure also during extraction.  With all these variables one wonders if the end product of some of these machines is not actually coffee!  i.e. load coffee grinds here, press lol the buttons, out comes Fanta!  Oh the notes, notes, notes....  >:D

you crack me up. Lol.

FreshCoffee2

on 1433592042:

Coffee machine makers generally calibrate the heat band from 89 to 92 degrees at the boiler Unless your machine has an electrically heated group head you need to allow time for all components to reach a good operating temperature Hope my answer helps  KK

Yes it does ! The only thing I would note is the brew water temp band is roughly 89 to 92 degrees at the group rather than at the boiler. At the boiler, depending on where the temp is taken, however somewhere at the top, the temp will be somewhere in the vicinity of 105, for roughly a correlation of say 90 degrees at the group on Sue's machine (depending on which part of the heat cycle the machine is actually at, at any particular time...). That is for machines that we have set up together with the manufacturer, for this market. Machines set up for the Italian market usually run hotter bnecause of the different coffee used over there, and may be running another 5 degrees or more at the top of the boiler, for something also correspondingly hotter at the group. That is for robusta type blends per the italian market. If you do that here, you burn the hell out of our conversely arabica based coffees.....    When I was still working in the business, I was using PID controlled BFC machines in my Cupping Lab for quality control. While they are designed to deliver a more precise temperature control at the group, and are quickly and easily changed for different coffees, I have never felt the need to use one at home for personal use. If I dont get an optimum coffee out of my HX machine at home, I am fully aware its more likely the nut behind the group handle operating machine and grinder, than anything to do with the well designed HX machine that I happen to be using..... 

Koffee_Kosmo

on 1433632923:

Thanks KK and very interesting re the second crack temp correlating with the boiler temp. band. Thanks Brett and GeekKopi  .

Based on the above information I posted Water temp that is to cool produces a sour tasting coffee Water temp that is to hot produces a burnt tasting coffee Also a lighter roast that hasn't degassed properly will taste grassy when made on an espresso machine Different roast levels allowes the coffee to be brewed by different methods For example - Lighter medium roasts are better suited to syphon and or boiled type coffees like Greek/Turkish KK

Cuir Beluga

Some of this is getting to technical for me and it is going over my head. I have read every word though  . Paranoia question for today....... Is it normal for the pump to cut in and out while the machine is sitting there idle? Hubby says something about that is how boilers work and I am verging on pulling my hair out. Maybe it is time to pull the Icona out  ;D.

Koffee_Kosmo

on 1433649316:

Some of this is getting to technical for me and it is going over my head. I have read every word though  . Paranoia question for today....... Is it normal for the pump to cut in and out while the machine is sitting there idle? Hubby says something about that is how boilers work and I am verging on pulling my hair out. Maybe it is time to pull the Icona out  ;D.

The pump will come on to fill the boiler when the sensor is activated for low water level It should not do it that often unless you have a leak Some times one does not turn off the steam or water wand tight enough and may leak drip by drip to lower the boiler level , thus activating the pump KK

Cuir Beluga

Thanks KK, I am wondering if maybe I left the steam on a bit or something. Perhaps I'm just not cut out for all of this  :head:.

Dry_bean.

Don't get hung up on the technicalities Sue, some of the stuff gets pretty geeky, all you need to understand are the basics, pretty much like a car, most of us have an understanding for what is normal when we drive, we know not to drive on a flat tyre, and react by taking it to a mechanic when we see a warning light or hear an unusual noise. Re the pump, KK is correct, it's not normal for it to cut in and out unless water/steam has been used, you should only hear the pump run when pulling a shot, or after drawing water from the hot water wand, if your sure the taps have been turned of and the pump continues to cut in and out intermittently I would suggest getting the machine checked over, I presume it's still under warranty. As far as I'm concerned most of us buy espresso machines to enable us to make and enjoy very good coffee at home, not spend every waking minute obsessing about our technique or whether the machine is set up exactly as it should be. Once your machine is set up correctly it should provide years of trouble free service, all you should need to do are routine maintenance jobs i.e. keep it topped up with water, back flush regularly and replace the group head seal now and again. Forget the tech talk and concentrate on enjoying the coffee your producing.  

GeekKopi

Hi Sue as others have said, the pump should only turn on while pulling a shot, or after enough water has been drawn out of the boiler (usually after steaming or using hot water wand) for a refill. Also, sometimes when the machine is turned on the pump will engage to top the water in the boiler. Just monitor it closely over the next couple days and if there is something happening out of the ordinary call up the shop you bought it from and let them know. Getting back to temp, just let the machine warm up for 30 mins with the portafilter locked in the group head then prepare your coffee and enjoy. simples.... If you need any help feel free to PM me and I can provide my number and we can talk on the phone. glad to help out.

Cuir Beluga

Will do Db, it is all a learning curve I guess. I am sure it must have been the tap or steam left slightly open. I left it on while hubby and I went out and Matt said the pump never came on. I just had a boo hoo woe is me moment  :P. Thank you GeekKopi for your kind offer. We'll see how it goes. I just had a cracking cappuccino not long ago so I am thinking it is all in my head rather than fact  ::).

Brett H

I sometimes hear my pump come to life while the machine is idling.  Its no big deal unless it's frequent in which case you have a leak.  Check under the machine for water and around the seam and hot water taps/joints for water or steam vapour.  If none, don't stress! 

FreshCoffee2

Hi Sue, its all part of the learning curve dont worry....nothing wrong. Give yourself say...about a month from first purchase, and you will have gotten well used to the workings and machinations of your new heat exchanger (HX) machine.  It works and behaves in an entriely different manner to your previous machine (and so it should, for incomparably better all round "performance"). Take care, A

Cuir Beluga

Thanks Brett, if it continued I would get hubby to have a look for leaks, there is nothing on the cupboard top and I am not tall enough to see inside  ^-^. Thank you Attilio, I thought I had it down pat but clearly this isn't the case. Oh well, it is all part of it . Thanks again.