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Thread: Espresso temperatures

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    Espresso temperatures

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    In my quest to get on well with Miss Silvia, I would like to determine what is the "good" espresso water temperature.

    Using a dial type drink thermometer (the type used for milk frothing measurements), I measured the water coming out from Slivie after she has been on for about an hour or more, both from the Portafilter and from the frothing wand - but not in steam mode. In both cases I extracted a full cup volume, to minimise temperature losses due to warming the cup itself. I also held the tip of the thermometer away from the wall of the cup, to get a true measurement of the central part of the hot water.

    In both cases my thermometer showed about 72 deg C, which I thought was too low, hence this post.

    So;

    Question 1: What temperature do others get? Please specify machine and temperature, when expressing water without coffee, and then with coffee (short black, of course).

    Question 2: What is the "recommended" ideal temperature? I thought that the water hitting the coffee grind is meant to be 92 deg C, which should be therefore what comes out when there is no coffee loaded or from the wand. Even allowing for some cooling, I would have thought that 72 was too low.

    Question 3: Can the solenoid pressure be adjusted on Miss Silvia? I am suspicious, that mine has too high a pressure, resulting in the water passing through the coffee grinds too quickly ( and not hot enough), and giving poor quality of extraction.

    Thanks for your input...

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    Re: Espresso temperatures

    Hello Paul,

    just quickly and not precicely as you requested:

    "Well priced" dial type thermometers are often "out" so I dont really use them for this purpose. I use a reasonable quality digital thermometer. I push a foam takeaway cup up into the group ring area, poke a hole just above the bottom and just big enough to get the thermometer probe into the cup, and push it in.

    Activate the group and read the temperature at whatever part of the pour you wish to measure but remember you only need to pour out very little say no more than 60 ml. (Theoretically 30ml for the brew and another 30 mll to account for water that would have remained in the puk)Aim to read somewhere around 90 to 92 degrees C. but the spec is around 88 to 93 degrees depending on whose "bible" you read. Loss in temp is quick so dont just stick the thermometer in a cup on the drip tray, and dont use a cup that will absorb heat from the water.

    We generally expect a reading in the mid to low seventies for the actual brewed espresso temperature in the cup, the temp loss is great, this would be considered normal and is why everything should be prewarmed. Temperature loss is your enemy.

    The group solenoid is not an adjustable item, it is no more than an electric tap that simply opens or shuts off the flow of water when electrically energised.

    You are probably referring to pump pressure and whilst many will tell you to adjust or modify so you can adjust the pump pressure, I have never seen a silvia that I couldnt brew a decent espresso out of as set by the factory. Yes it may be improved, but what I am getting at is that it is unlikely that any standard factury setting will result in your machine not working properly except if it has actually "broken down" in some way.

    Flow and pressure are not necessarily related and adjusting pressure up or down will not I think increase or reduce flow. The flow from your machine is governed by the designed set up of the pump, and the backpressure to that resulting from the fineness of grind supplied, the size of the dose supplied, and the pressure of the tamp supplied (by you, in the filter).

    Looking specifically at the last sentence of question 3, I would be concerned that you may be barking up the wrong tree in chasing machine problems that may not be present. It is very possible this may be due to operator technque. Do you live near any coffesnobs or anyone for that matter, that could quickly check your machine (not with instruments) and simply advise whether it is working properly and doing what it should?

    Hope this helps.

    Regardz,
    FC.

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    Re: Espresso temperatures

    Quote Originally Posted by pszilard link=1166132606/0#0 date=1166132606
    In my quest to get on well with Miss Silvia, I would like to determine what is the "good" espresso water temperature.

    Using a dial type drink thermometer (the type used for milk frothing measurements), I measured the water coming out from Slivie after she has been on for about an hour or more, both from the Portafilter and from the frothing wand - but not in steam mode. In both cases I extracted a full cup volume, to minimise temperature losses due to warming the cup itself. I also held the tip of the thermometer away from the wall of the cup, to get a true measurement of the central part of the hot water.

    In both cases my thermometer showed about 72 deg C, which I thought was too low, hence this post.
    Hi pszilard....

    Those type of thermometers just wont "cut it" when it comes to measuring anything other than the temp of a large volume of milk/ water...

    Because of the large mass of metal, they "steal" too much heat from the liquid under test and give a low reading (they also have to be immersed quite deeply in the liquid..... and you should not be measuring any greater volume than 60ml. (cold water replaces the hot in the boiler and reduced the temp).

    You need to beg, borrow or buy a multimeter with a thermocouple probe.... these have a small bead at the end which you can place into the pf - through the spout - or you can also use a foam cup - but only "extract" 60ml for your measurement.

    Question 1: What temperature do others get? Please specify machine and temperature, when expressing water without coffee, and then with coffee (short black, of course).
    You will need to get the correct type of measuring device to get valid comparisons.

    Question 2: What is the "recommended" ideal temperature? I thought that the water hitting the coffee grind is meant to be 92 deg C, which should be therefore what comes out when there is no coffee loaded or from the wand. Even allowing for some cooling, I would have thought that 72 was too low.
    The temp should be about 92-93 deg C ... although some like to brew as low as 88 deg C.... Id recommend 92-93.

    Question 3: Can the solenoid pressure be adjusted on Miss Silvia? I am suspicious, that mine has too high a pressure, resulting in the water passing through the coffee grinds too quickly ( and not hot enough), and giving poor quality of extraction.
    There is no pressure regulator in the current model Silvias (the latest model will have one). Most do use a bit too much pressure (10.5 to 11 bar compared to the recommended 8-9) but this does not cause a problem if you are using the correct volume of grounds, at the correct level of fineness and with the correct tamp.

    But get yourself the correct measuring instrument before getting too concerned!

    (beaten.... and what FC said above!)

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    Re: Espresso temperatures

    Doing a Google, has turned up the following:

    From http://www.coffeeresearch.org/espresso/potential.htm
    Water temperature - The water temperature should be stable and somewhere between 92-96C. The choice of the espresso machine is very important to both water temperature and temperature stability.
    http://www.lucidcafe.com/cafeforum/factors.html states 203 deg F which equals 95 deg C.

    And finally here is another informative link: http://www.sweetmarias.com/prod.rancilio.shtml

    ps: I just weighed mySilvia PF handle without a coffee basket and it was 575g.

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    Re: Espresso temperatures

    I did have a 1hr lesson at Di Bartolis which is where I bought the Silvia. I know Renzo is happy for me to go back for another run and even take my own Silvia for comparison to his demo unit.

    I will also go to Jaycar and look for a thermocouple digitherm.

    And thanks for the quick replies too. All responses are absorbed into the gray matter :D

    Cheers,

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    Re: Espresso temperatures

    Renzo is a good bloke & will help you, just take the machine back in and all will be well.

    I would however advise against rushing out to buy any form of instrument to measure anything with on the machine. Its pointless.

    The machine needs to work well as set by the factory. Good and understanding operator technque is a given.

    Heres a hypothetical. If after taking your readings they dont match with what you expect or what you have read or been told, but the machine is set as per the factory and the vendor advises it works just as it should, then what to do? *Rancilio and their importers, agents and vendors are not going to go modifying a factory set machine particularly if it can be demonstrated to do what it should be doing irrespective of what you have measured.

    The moral of the story is....dont read too much into all this tech stuff that gets thrown around on websites. Talk to Renzo.

    Regardz,
    FC.

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    Re: Espresso temperatures

    Renzo, I can understand your need to know. Its natural when so many figures are flung around, and you feel as though youre working in the dark unless you know what your own machine is doing.

    Dont go electrocuting yourself.... but when you get a digital multi-metre with thermocouple, first of all immerse the thermocouple into boiling water.

    Take a reading to ensure it is 100 degrees (at sea level).
    I wont even attempt to go into the ice bath calibrations --boiling water does it for me.

    Satisfied your gadget is accurate, attach the thermocouple on top of the boiler, close to the thermostats up front. Once again, be careful -- there are deadly live wires all round.

    If you brew when the temperatures on the boiler stabilises around 108 to 110 degrees, the temperature exiting the portafliter should be at the required 93-95.

    Dont buy a digital thermometer -- its response time lags way behind whats happening in the boiler.

    Use a good DMM or a PID.

    --Robusto

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    Re: Espresso temperatures

    Quote Originally Posted by robusto link=1166132606/0#6 date=1166167247
    Renzo, I can understand your need to know. Its natural when so many figures are flung around, and you feel as though youre working in the dark unless you know what your own machine is doing.
    Yep so do I.

    Whether you are a "snob" (in the coffee world), a "geek" or a "nerd" you have to know what is going on and why. 8-)

    Im a frequent contributor to Whirlpool as well (the "geek" Internet users site).... and it is the same there.... why do I have those figures in the modem?, why is my line so bad? how can I measure this or that?...

    We must be a pain in the A to suppliers of goods and services because we ask why (or why not) and we want an answer...... we will complain if we dont get one (or if we see it as a "brush off")... we discuss what is happening and we try to improve things.... it is the nature of the beast which we are. And its people like us who often make things better for the consumers who dont care about such issues.

    I say well done to the snobs, geeks and nerds of the world! (and sorry to the suppliers to whom we cause grief) - but we will make a difference!!

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    Re: Espresso temperatures

    Gday Paul,

    Id go with FCs advice in the first instance, makes sense and he has been "in the game" a long time. Worry about all the other stuff after you have Silvia singing and dancing to your own tune ;), funny thing is, after you get to this stage theres a lot less reason to start playing around under the bonnet :o

    Mal.

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    Re: Espresso temperatures

    The only thing i would add to the above is that when answering a similar question a while back, I replicated your test (which another reader had done) and found that the 70 something C from the milk therm was about 92 C from inside the filter basket using a thermocouple.
    I agree that this is interesting but unnecessary.
    The simplest thing I do on my botticelli (similar to silvia) is to let the element heat the boiler until the thermostat turns it off and then do a quick flush to get rid of boiling water before I put the handle in to brew. It does make for a sweeter extraction on my machine (there are people who would disagree with this process- it works for me on both my very different machines). It is much simpler than temperature surfing and getting paranoid about the process.

    Im not sure if silvia gets this hot- FC or others would know.

    Brett

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    Re: Espresso temperatures

    Brett, not sure whether I read your post correctly. You leave the portalifter OFF until youre ready to brew? Is that correct?

    --Robusto

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    Re: Espresso temperatures

    Question 2: What is the "recommended" ideal temperature?
    I would however advise against rushing out to buy any form of instrument to measure anything with on the machine. Its pointless.
    I could not agree more!

    There is only one way to adjust temperature that makes any sense and that is something that I will reveal shortly ;P For now, I want to point out that temperature is only really worth concentrating on after you have the other variables under control. A good test of your barista skills is to get a bunch of 30mL shot glasses and a stopwatch and see if you can get five 30mL pours in a row that are all within a three or four second extraction time window.

    As others have said, measuring espresso temperature is a lot more involved than simply using a dial thermometer. In addition to a lack of accuracy, Im surprised that no-one has mentioned that dial thermometers have quite a lag time due to the mass of the probe.

    All temperature measuring devices will give you a degree of error. Even a relatively cheap multimeter with a K-type thermocouple will probably give you +/- 3% in error. That means that if you read something like 92C it could be anything from roughly 89C to 95C. Then theres the whole problem of measuring things consistently. Measuring what is coming out of the spout as opposed to measuring water in free flow without a portafilter, measuring with a bead probe on top of a tamped bed of coffee or measuring with a probe in the coffee will all give different results. Then you need to remember that the room temperature ground coffee will rise in temperature as hot water flows through it ... so you either need to pick a point in time to measure the temperature at or you need to actually plot it as a graph!!

    All of this makes for a major headache when you are trying to compare brew temperatures across machines. Someone might well say "95C is the best brew temperature," but that is pretty much entirely meaningless unless they specify the method by which that temperature reading is obtained and the audience then uses the exact same piece of thermogadgetry to go and measure it in the same manner. In fact, in order to do the temperature testing on the machines trialled for the World Barista Competition, Greg Scace, a scientist from NIST, was enlisted and he came up with a specially designed thermofilter. Combined with an appropriate multimeter, the "Scace device" costs over $US500!

    So all of this brings me to my point that slavishly extracting at a recommended temperature is not actually that likely to get you the result that you want in your cup. The only worthwhile way to adjust temperature is by taste. For example, if something tastes really sour, go to a higher temperature. If something tastes burnt and ashy, go to a lower temperature. I work on commercial machines that have adjustable temperature readouts that are calibrated at the factory, but it simply doesnt matter whether your machine has a digital temperature readout, a bar pressure gauge or whether you just wait X seconds after the heating element goes out. The principle is the same.

    What temperature do others get?
    When I had my Silvia, I got the best results when I waited between about a minute and a half and two minutes after the heating element light went off. I have brewed espresso between 88C and 97C according to the temperature readouts on the machines that I have used. There is certainly no generic temperature that will work with everything, but Id guess that most commercially available blends would probably like temperatures between 91 and 95C. On my home machine, 1.0 bar at the upper end tastes right for the blends that I have been using. Generally, lighter roasts will need higher brew temperatures and darker roasts will need lower brew temperatures, but this is not always the case.

    To bring the discussion back to you, if one day you roasted something a bit too light, you might, for example, want to have a go at brewing it immediately after the element light goes off to see if it likes that hotter temperature a bit more.

    Cheers,

    Luca

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    Re: Espresso temperatures

    Quote:
    Question 3: Can the solenoid pressure be adjusted on Miss Silvia? I am suspicious, that mine has too high a pressure, resulting in the water passing through the coffee grinds too quickly ( and not hot enough), and giving poor quality of extraction.


    For the past few weeks, I have been experimenting with the brew pressure on my machine and I definitely think that a lower pressure makes ones life easier. Im sitting at about 8.5 bar at the moment.

    The silvia, unfortunately, has neither a brew pressure gauge, nor an adjustable overpressure protection valve. This means that to tell what the brew pressure is, let alone to adjust it, you need to have access to a portafilter-mounted pressure gauge.

    For years, some silvia owners have modified their machines. I never did this to my machine because it is a procedure that carries some potential risk and will definitely void your warranty. Horror stories that I have heard include unseating parts on the inside of the boiler, allowing water to drip back into the reservoir so that an air pocket develops in the boiler and, of course, electrocutions and breaking other random parts. Of course, some people have reported success, but, given the risks, I would advise steering clear of it.

    Rancilio seems to have heeded the call that machines should work well ex-factory. The latest US silvias seem to have an adjustable OPV. If and when this model makes it to Australia, and it might have already for all I know, perhaps the part will be available to buy so that you can retrofit it.

    Now, I have talked a lot about the minutii and I want to finish off this post by reiterating the old adage that the problem is usually on the handle side of the portafilter. By far the best investment that you can make is to buy some decent coffee and plough through it in a session working on your barista technique. In the first session, dont worry about temperature at all and dont drink any of the espresso. Just get some shot glasses and a stopwatch and work on consistency. For $15 in coffee and 45 minutes of your time, I think you will be very happy with the improvement. This was the very first thing that I did when I got my machine and I am very glad that I did so, as it enabled me to get decent shots in the first few days. I have attached a photo to prove that Im not kidding ;P On your second session, you can start tasting some coffees, but Id probably try to keep it to five or fewer shots in a session if you want to taste them because the group will probably heat up a bit. Of course, doing a training course will skip you ahead even faster, but you will get the most out of it if you do a session at home first.

    Quote:
    The simplest thing I do on my botticelli (similar to silvia) is to let the element heat the boiler until the thermostat turns it off and then do a quick flush to get rid of boiling water before I put the handle in to brew. ... Im not sure if silvia gets this hot- FC or others would know.


    The silvia group is not directly on the bottom of the boiler as it is in your botticelli, so if they had the same tstat, Id expect the temp to be a little bit colder. However, a shot with a warmed silvia immediately after the light goes off would have tasted quite burnt to me, so maybe the tstats arent the same. Just idle speculation. But I find it difficult to understand how a flush that gets rid of boiling water would work ... I havent ripped open a botticelli or anything, but if the brew water comes from the bottom part of the boiler, as it does on the silvia, I would expect it to be the coolest water in the boiler ... so the rest of the shot would be too hot. Its not like a HX, where you flush out overheated water. But this is a lot of speculation - there could be a million other things like the effects of convection currents and pressurised systems ... frankly, I prefer just sticking to pressing the buttons in some way that gives good coffee ;P

    Cheers,

    Luca



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    Re: Espresso temperatures

    Quote Originally Posted by robusto link=1166132606/0#10 date=1166173366
    Brett, not sure whether I read your post correctly. You leave the portalifter OFF until youre ready to brew? Is that correct?

    --Robusto
    No dont leave handle out- just take it out to dose after I do a flush to get element heating, then flush boiling water then handle back in- very short process, but yes, the handle stays in the rest of the time the machine is on.
    Brett

    ps re Lucas comment about hx flush and botticelli- I agree theyre not the same but the botticelli does have boiling water (or close ) coming out of the group head after the thermostat turns the heater off and if you dont flush the coffee tastes burnt. Im not sure why this is because there isnt the E61 heating going on (not an E61 machine!). Im aware of what Sparky said about boiler currents.
    Whatever is going on, with the flush, I get results close to the bezzera after a cooling flush. If it is just till the water stops sizzling I get a sweet unburnt espresso. If I flush much longer I get the nasty under temp bit (and heater goes on during extraction) With no flush you get burnt coffee.
    An aside- this is my second bott- the first one (dropped on a concrete floor by a technician and replaced) didnt need the flush.

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    Re: Espresso temperatures

    Thanks for those posts, Luca, there is a lot of good information there.

    Perhaps someone could get you a nice set of matching coffee cups for Xmas? ;D

  16. #16
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    Re: Espresso temperatures

    Quote Originally Posted by luca link=1166132606/0#11 date=1166179875
    What temperature do others get?
    When I had my Silvia, I got the best results when I waited between about a minute and a half and two minutes after the heating element light went off. *I have brewed espresso between 88C and 97C according to the temperature readouts on the machines that I have used. *There is certainly no generic temperature that will work with everything, but Id guess that most commercially available blends would probably like temperatures between 91 and 95C. *On my home machine, 1.0 bar at the upper end tastes right for the blends that I have been using. *Generally, lighter roasts will need higher brew temperatures and darker roasts will need lower brew temperatures, but this is not always the case. *


    Cheers,

    Luca
    I agree with luca, Ive found that if I wait about a minute and half to two minutes after the light goes off Im pretty happy with the results. Of course, I should point out that we are talking about the exact same Silvia as I bought his old one. *;D

    That said, I have done a bit of experimenting anyway and have come to the same conclusion as luca did. As has already been mentioned, flushing water through the group just before you brew is a good idea. After a while, I found you can get a really good idea of what temperature the water is just by watching. * *

    Ive been re-learning a lot of things myself since getting Silvia, its been a long time since I was behind a machine in a cafe! You can go crazy reading things on the net, it can be helpful too, but sometimes I find it gets a little much. IMO nothing beats standing in front of her with a kilo of beans and pulling shot after shot until youre happy and consistent with your results. No amount of measurement can replace the human palate *:)

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    Re: Espresso temperatures

    For quite some time before I PIDd Silvia, I used a digital multimetre with K thermocouple to pull shots at the optimum temperature.

    Problem with that of course, is that as with surfing using X time after light goes on, the temperature is very dynamic, not stable. You are relying on the thermal mass of the group head and portafilter to keep things steady while inside the boiler dynamics are still in play.

    At least, the DMM and themocouple does narrow the wide heat range to a manageable ballpark. And you can see the instant temperature plunge as cold water displaces the hot. Often as much as 15 degrees or so in the space of a 60 ml pour.

    -Robusto

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    Re: Espresso temperatures

    I agree with luca, Ive found that if I wait about a minute and half to two minutes after the light goes off Im pretty happy with the results. Of course, I should point out that we are talking about the exact same Silvia as I bought his old one.

    giggled like a schoolgirl!

    Thanks for those posts, Luca, there is a lot of good information there.

    Perhaps someone could get you a nice set of matching coffee cups for Xmas? Grin
    Your welcome, but you can pry my random demitasses from my cold dead fingers! Each one has memories of the Italian espresso bar that I begged, borrowed or stole it from.

    The LM demitasses are perhaps my most prized, as they were given to me by Ron Cook, who is now one of the owners of LM, after he hosted me on a tour of the factory one morning.

    Not that Im materialistic ;P

    Cheers,

    Luca

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    Re: Espresso temperatures

    Well, I have a few more findings to report. Discard as irrelevant, or absorb, or respond - your choice. Whatever you choose, I want to start by wishing all a very Happy Christmas and a prosperous New Year.

    I have treated my self to a DMM (digital multi meter) which has an external temperature probe. I bought one which has 0.75% accuracy and also interfaces to a PC to chart readings over time. I also got 2 sensors: one is in a "probe" and looks like a ball point pen refill and is completely submersible and the other is a little bead and is ideal to attach to a surface like a boiler, etc.

    My first action was to compare the two probes in ambient air temperature, to see if they registered the same! They did.

    Next I got a mug and poured 2cm deep water out of the kettle with both my electronic and ordinary non-electronic dial type thermometers resting at the bottom. The electronic one showed about 8 Deg higher reading. I then filled the mug full, and to my slight surprise the two types of thermometers now showed the same! CONCLUSION: The non-electronic dial thermometer need full immersion as it derives its true value if the whole of its wand is immersed and has the same temp, whereas the digital sensor just reads at the tip, so full immersion is less critical.

    Next step was to measure water coming out of the PF with no coffee. I am fully aware that this is cooler than water when it would hit the coffee grinds, however it still serves as a good COMPARISON between machines. All measurments were taken with machines stabilized and having been on for over 1 hr. My Silvia was producing 77 deg C and Di Bartolis Expobar Minore 2 was 80 deg C. A friends La Cimballi was at 87 deg C. Hence my questions to forum members what temps they were getting.

    My next observation was just comparing a glass (for latte) versus a dual walled stainless espresso cup. The single walled glass, clearly looses heat quicker and is hotter to hold (uncomfortable), whereas the stainless cup is better insulated and comfy to hold. CONCLUSION: I will use the stainless for latte as well as cappuccino :D

    I then pulled an ok shot on the Silvia and then went through the milk frothing process, which required heating up the boiler/bleeding off excess water and steam and then frothing the milk. The milk was frothed to 70 deg C, but due to its thermal inertia its temp kept rising even after the steam was removed, and topped at 77 deg, but with no ill effects on taste. The final latte was made and measured at 70 deg C which was surprisingly good as I expected that to cool a bit more. This was in the stainless cup.

    Next observations relate to my coffee and the Silvia. I had home ground coffee from a Saeco 2002 set to 1 which has been approved by Renzo at Di Bartoli, and coffee from the locally well respected coffee roaster, Whithams. They had ground to espresso setting on an unspecified commercial grinder. I was using a 58mm polished metal slightly convex tamper. The Silvias PF with a double basket weighed exactly 600 g. If I filled it to the line after tamping, it took 15g of home ground coffee and a double shot into one cup produced 30 ml of coffee in 20 sec. with ok crema. However the coffee had suspended granules in it. Loading the commercially but locally ground coffee produce clear coffe but stuff all crema and went though too quick, no matter how hard I tamped it down.

    Question 1: can the Silvias thermostat be adjusted if one goes under the machines panels?
    Question 2: can the Silvia be adjusted for the pumping pressure?

    I am wondering if a better extraction could be achieved by raising the espresso temperature to closer to 92 deg C at the shower screen (probably equivalent to the La Cimballis 87 deg at the PF) and reducing the pumping pressure to about 11 bar so that the water takes a little longer to go through the grind.

    I would especially like to hear from people that have played with either a OID on the Silvia, or have an Expobar Minore with adjustable temperature.

    My next experiment will be to try the temp surfing, and froth the milk first and then wait a measured number of seconds before pulling a shot at a slightly higher than standard temp. I could pump hot water out of the wand and when it gets to 90, then switch to pull the shot. What do you reckon?

    Over to you for comments, flames and suggestions...

    ps: Have you seen http://www.dibartoli.com.au Di Bartolis new web site lately? I think its cool!

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    Re: Espresso temperatures

    With the preground coffee you used wouldnt that be stale by the time you used it? If so I wouldnt expect much crema either. Did it taste as good as the home ground beans?

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    Re: Espresso temperatures

    Was kept in an airtight bag in the freezer, but the taste was junk, so I chucked it in the sink. It might be ok for plunger though... Maybe used for visitors ;D

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    Re: Espresso temperatures

    Quote Originally Posted by robusto link=1166132606/15#16 date=1166245588
    For quite some time before I PIDd Silvia, I used a digital multimetre with K thermocouple to pull shots at the optimum temperature.

    snip 8<

    -Robusto
    Which PID do you have? Is it worth the hassle and cost? Is a PID equipped Silvia a better choice than a Minore II with its standard temp control?

    I see a lot of cursory mention of the Minore 2, but no actual user evaluation or feedback. I would like to know how owners feel about the Minore, are they glad they bought that instead of something else like a Giotto, and why?

  23. #23
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    Re: Espresso temperatures

    I passed on the Minore II and bought the Leva.
    I didnt see the need for all the extra gadgety stuff.
    Im happy enough with my decision.
    But as I cant compare one to the other I have nothing to be envious of if indeed the extra flashy bits help make better coffee.

  24. #24
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    Re: Espresso temperatures

    Quote Originally Posted by pszilard link=1166132606/15#21 date=1166670661
    Quote Originally Posted by robusto link=1166132606/15#16 date=1166245588
    For quite some time before I PIDd Silvia, I used a digital multimetre with K thermocouple to pull shots at the optimum temperature.

    snip 8<

    -Robusto *
    Which PID do you have? Is it worth the hassle and cost? Is a PID equipped Silvia a better choice than a Minore II with its standard temp control?

    I see a lot of cursory mention of the Minore 2, but no actual user evaluation or feedback. I would like to know how owners feel about the Minore, are they glad they bought that instead of something else like a Giotto, and why?
    Yes, I would say it is definitely worth the "hassle" and cost. *The hassle is a once-off: sourcing, installing and tuning the PID. That done, in one afternoon, you then eliminate, permanently, the greater hassle of guessing what temperature you are brewing at, or the need to surf.

    The red digital read out (very large digits at that) tell the temperature of the boiler at a glance, and the line underneath states the set temperature.

    Much HAS been written, even on this forum, about the Minore. It was a big hit when it first came out, sort of a rough-around-the-edges version of the more attractive Giotto.

    This is a different class of machine to the Silvia, being a heat exchanger type with twin boilers. *But it will cost you three times as much as a Silvia.


    *I am very happy with my PID, it is a two-line Auber SYL *model, bought for a very reasonable price brand new from the USA on that famous auction site.

    A PID keeps your machines *temperature stable. You are not brewing on an up-heating or down-cooling cycle. You are brewing at your desired set temperature.

    -Robusto



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    Re: Espresso temperatures

    Hi pszilard and everyone else

    Im still very new to the Sylvia so I did a bit of temp testing myself. I used a Brannan laboratory thermometer that is very accurate and tested as follows:

    Warmed machine for 15 mins.
    Pre warmed cups with hot water from portafilter.
    Waited for heating light to go out then imediately poured a blank pour into the cup with thermometer in cup.
    Result, 91 degrees in the cup straight up. Several pours over 10 minute period and temp only varied by one or two degrees but not under 90.

    Very similar results from getting hot water from the steam wand. First attempt 88 degrees in a pre warmed cup. Second attempt around 92C.

  26. #26
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    Re: Espresso temperatures

    Thanks for that, Monkey.

    Inspired by your post, Ive repeated my experiment and was able to record 90-91 C after the 3rd full cup full of water. It looked like it is really necessary to run the water a bit to build up the temp in the internal piping. I guess that is temp surfing?

    Anyway, Ill try it with a shot tomorrow morning with coffee. Its too late for caffeine tonight.

    Thanks for sharing...

  27. #27
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    Re: Espresso temperatures

    Did you place the cups on the drip tray and let the water fall into it through the air?

    If so, the temperature reading is below actual ex-group.

    It cools somewhat through the air. (one reason why there is so little room between spout and tray on the Silvia.)

    The machine should be stabilised by pre-heating for up to an hour.

    The thermocouple needs to be placed as close to the shower screen as possible, allowing the water to empty into an insulated cup. Its the temperature hitting the coffee grounds that counts, not the temperature in the cup.


    Silvias reputation for making good coffee comes not so much from the wildly-fluctuating boiler temperature and thermostat....but from the massive group head and portafilter.

    They keep temperatue steady during the 30" extraction, even though the water temperatue within the boiler is changing rapidly.

    --Robusto


  28. #28
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    Re: Espresso temperatures

    Well, this morning I kept pulling hot water until its temp reached 82 deg. Then made a "perfect" espresso. Just like pulling Guinness. Had to run 5 full cups of water before though, which I chucked back into the tank, for conservation.

    I guess my next thoughts are PID or Minore...

  29. #29
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    Re: Espresso temperatures

    Quote Originally Posted by pszilard link=1166132606/15#27 date=1166741968
    Well, this morning *I kept pulling hot water until its temp reached 82 deg. Then made a "perfect" espresso. Just like pulling Guinness. Had to run 5 full cups of water before though, which I chucked back into the tank, for conservation.

    I guess my next thoughts are PID or Minore...
    Sounds like youre heading in the right direction ;-)

    One thing to keep in mind is that a 2nd hand Silvia will bring around $500 or so....a Silvia with PID....probably also around $500....I guess its like having a souped up car- Joe average doesnt pay much, if anything for your mods...

    On the other hand, a Minore will maintain temp. stability shot after shot and you have the added convenience of pulling your shot whilst texturing your milk. The Silvia is a great unit, but sloooooow if you want to do more than a couple of coffees at a time...

    The changeover to a good HX or Dual boiler represents a significant investment...but it should be life-long subject to good maintenance of the machine....

    I know someone who has a couple of Minores and a keenly sharpened pre-xmas pencil.. ;)

  30. #30
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    Re: Espresso temperatures

    interesting topic :) Its got me thinking a Silvia with a pid, and and an adjustable pressure ought to pull just as good shots as any duel boiler and the potential to be better then a hx apart from user friendliness. my understanding of a hx machine is that there is limited user control over temperature. (is this right?) im getting more convinced about getting a pid every day. 8-)

  31. #31
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    Re: Espresso temperatures

    Quote Originally Posted by muppet_man67 link=1166132606/15#29 date=1166862800
    interesting topic :) Its got me thinking a Silvia with a pid, and and an adjustable pressure ought to pull just as good shots as any duel boiler and the potential to be better then a hx apart from user friendliness. *my understanding of a hx machine is that *there is limited user control over temperature. (is this right?) im getting more convinced about getting a pid every day. 8-)
    Hmm...not really. I think this is more than a tad generalised:

    1. A machine is not simply the sum of the parts its made from. Design is a significant factor.
    2. Big differences in group head design and therefore thermal stability
    3. The Silvia is an excellent machine.....but feisty...Even just that fact that a finer grind is required makes things a whole heap tougher...
    4. HX machines are designed to do espresso- however if you want to use something heaps lighter or darker (perhaps not so well suited to espresso) an adjustable machine may aid in the extraction of an acceptable shot.
    5. There is generally way more shot variation caused by the nut on the group handle ;)

    Bottom line is 10 shots from a Silvia v 10 from a good HX or dual boiler and its no contest...

  32. #32
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    Re: Espresso temperatures

    I am leaning towards a pid myself. I think the Minore might cost quite a few kilos worth of beans ;D

    I was looking at the PIDkits 935 unit, which includes a timer function in the control unit. I was wondering if one could use that to control the bew switch to auto shut off at a preset time, like 25 sec, or whatever. Wouldnt a semi-auto Silvie be kewl? Silvia + PID is still 50% of a Minore.

    I think a bit more procrastination is required. Anyone for a cuppa, while I put my thinkin cap on?

  33. #33
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    Re: Espresso temperatures

    Quote Originally Posted by muppet_man67 link=1166132606/15#29 date=1166862800
    my understanding of a hx machine is that there is limited user control over temperature. (is this right?)
    No, thats not right. With an HX, you can change your boiler pressure and that will change your brew temperature. If you so desire, you can then get really funky by doing things like flushing heaps of water, then allowing some time for the heat exchanger to heat up again so that you get a shot with a falling temperature profile!

    From my point of view, I dont really care whether Im using the PID on a multiple boiler to go from 93C to 95C or whether Im using a screwdriver to change the boiler pressure on a HX from 1.0 bar to 1.1 bar. Theyre just numbers. Either number gets rid of that slightly sour tang that my Kimel had or whatever ... and, after all, isnt that sort of thing whats important?

    The second you start being led around by a digital readout, you get blinded by whats actually in your cup. And thats coming from a guy who has just come home from one job working on a La Marzocco FB80 and will go to his second job tomorrow using a Synesso Cyncra!

    ... the potential to be better then a hx apart from user friendliness.
    In addition to Chris list, you might want to think about water distribution, preinfusion, rebound times, overheating on successive shots, delay before steaming and even drip tray size ;P

    Generalisations and conjecture are useful to a point. After all, if it werent for that, we probably wouldnt have many of the wonderful machines that we enjoy at the moment. But actual results have a habit of turning out the opposite to what youd expect. Now dont get me wrong - Im not saying that all HXs are going to be awesome. Im not even saying that all HXs are equal.

    Cheers,

    Luca

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    Re: Espresso temperatures

    Quote Originally Posted by 2muchcoffeeman link=1166132606/30#30 date=1166869753
    3. The Silvia is an excellent machine.....but feisty...Even just that fact that a finer grind is required makes things a whole heap tougher...
    is the finer grind not the result of higher pressure? and the pid would take out variables in water temperature? what other variables are there that would make it more feisty then other machines? if the pided silvia has had a good flush moments before brewing then I would imagine that the group head temp would be pretty stable. (ie if it is already at water temp then it cant really change during brewing.) I dont understand why it would increase to above the pid set temp?

  35. #35
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    Re: Espresso temperatures

    Quote Originally Posted by muppet_man67 link=1166132606/30#33 date=1166877530
    is the finer grind not the result of higher pressure? and the pid would take out variables in water temperature? what other variables are there that would make it more feisty then other machines? if the pided silvia has had a good flush moments before brewing then I would imagine that the group head temp would be pretty stable. (ie if it is already at water temp then it cant really change during brewing.) I dont understand why it would increase to above the pid set temp?
    Gday MM67,

    In essence, Chris was referring to Silvias made before the current crop exiting the factory. Newest Silvias have an adjustable Over Pressure Valve that is preset from the factory to be close to 9.0-9.5 BAR from what I have read. Previous Silvias used a NON-adjustable OPV that was preset to anything from 12-14 BAR. The result of this is that users mostly dialled in their grinders by decreasing grind size until the Silvia Choked and then backed off until a pour of 30/60ml was achieved in 25-30 seconds. Unfortunately, this means the grind had to be so fine as to provide sufficient back-pressure to the 12-14 BAR that the pump is delivering.

    The correct method for dialling in an older Silvia is to come from the opposite direction, i.e. set the grinder to a coarser setting so that Silvia is producing "gushers", then slowly adjust finer until you are achieving the requisite 30/60ml in 25-30 seconds..... This time though, the back-pressure from the puck alone is determining the actual brew pressure, not the OPV valve so shots will be a lot sweeter, more crema and a lot less finicky to slight variations in tamping force and dose levels, etc. Of course, if you want to pull Ristrettos in this scenario then you are plumb out of luck since as you grind finer to restrict the shots volume, you will find yourself backing up against the OPV setting again and having to grind ever finer to the point where eventually the coffee develops burnt like tastes coupled with bitterness.

    This can be overcome though if you are handy with tools and of a technical mind. The OPV can be reset to operate at much lower pressures by the addition of appropriate thickness brass washers such that it will operate at the preferred 8.5-9.5 BAR. This way, all your shots will be getting pulled at the correct pressure and you will avoid the cantankerous nature of the Silvia with an unadjusted OPV. If you do a search on this and other sites, you will come across info on how to adjust the Silvias OPV using washers.... Be warned though, this mod may well forfeit your machine warranty so suss out this aspect of it before you proceed.

    All the best,
    Mal.

  36. #36
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    Re: Espresso temperatures

    Mal and others- even the newie SIlvias require a finer grind like the old non-adjusted ones. My take on it is that the lower shower screen decreases the dose in the PF- therefore finer grind....

    Bottom line is that PIDed or not...theyre still fiddly...and feisty....and yes I still think that theyre a great machine....but they require a whole heap more work than any good HX or dual boiler...and thats before we even start to think about group head design, pre-infusion and similar....

    You can hot up a Silvia as much as you like but as Luca so correctly stated in another thread, its never gonna be a LM...

    2mcm

  37. #37
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    Re: Espresso temperatures

    Quote Originally Posted by 2muchcoffeeman link=1166132606/30#35 date=1166909570
    Mal and others- even the newie SIlvias require a finer grind like the old non-adjusted ones. My take on it is that the lower shower screen decreases the dose in the PF- therefore finer grind....
    How does this setup compare with other Rancilio machines Chris?

    Seems like a less than optimum design for such a highly regarded machine :-?

    Mal.

  38. #38
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    Re: Espresso temperatures

    Quote Originally Posted by Mal link=1166132606/30#36 date=1166943406
    Quote Originally Posted by 2muchcoffeeman link=1166132606/30#35 date=1166909570
    Mal and others- even the newie SIlvias require a finer grind like the old non-adjusted ones. My take on it is that the lower shower screen decreases the dose in the PF- therefore finer grind....
    How does this setup compare with other Rancilio machines Chris?

    Seems like a less than optimum design for such a highly regarded machine :-?

    Mal.
    Not Chris, but I can say this ... we have a scrapheap Rancilio S10 sitting in the repairs room at Venez and it seems to have the same group as the Silvia. So perhaps part of the reputation hails back to the oft-repeated statement that the Silvia has a commercial group head. Thats certainly true, but rancilio machines dont exactly enjoy a reputation as fantastic commercial machines. The switches are also the same as the s10 switches, I think. Other than that, Id expect everything to be pretty different.

    OK, so if you have read that far, you might think that I dont think that the Silvia is a very good machine. Thats true. But I do think that it is a good machine for the money. And thats not because the machine itself is great, but because it is simple and reliable, you can change the portafilter basket and the machine steams well without gimmicks ... those simple facts place it way ahead of the competition in its price range and are probably a big reason for its reputation.

    Cheers,

    Luca

  39. #39
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    Re: Espresso temperatures

    Thanks Luca,

    Very interesting.....

    Mal.
    P.S.
    Could be why so many people have increased success with LM and other alternative baskets, eh?

  40. #40
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    Re: Espresso temperatures

    You might be interested to read that I opened the top of my Silvia and installed a K type temperature probe into the boiler (there is a hole on the tope left, which is ideal for this) and measured the temp as it was warming up. The results were really amazing! We know of course that the boiler temp is going to be hotter than the water by the time the water reaches the coffee grind, but the variation of the temp is what freaked me.

    With the machine switched on, but not for steaming, the heater went off when the temp was 105 deg C, but the boiler temp kept increasing due to the thermal inertia and it peaked at 115C. It then started to cool and the heater only switched back on at 85C and it heated to 105C as before and so the cycle went.

    That is a huge 115-85=30C variation! I then pulled a double shot when the temp was at 85C and the boiler dropped to 70C. Remember that the recommended extraction temp is 92C. So this really illustrates the need for PID control. I am looking forward to doing the measurements once the PID is installed. :)

  41. #41
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    Re: Espresso temperatures

    Hi Paul,

    I, too, fitted a digital thermometer to the top of my boiler and got similar results. Actually, mine wasnt quite that bad ... something like 90 to 110, but whatever ...

    Sparky is the man to talk to about all of these results. The thing to remember is that you see whats going on at the top of the boiler, which is the point of maximum temperature variation (especially seeing as thats where the cold water inlet is). But the coffee sees what is happening at the bottom of the boiler, where the brew water is drawn. Im no PID expert, but, if nothing else, this shows that positioning of the PID probe is very important. Again, youd have to ask Sparky, but actually mounting a probe in the bottom of the boiler might be way more effective than the "plug and play" method of replacing the thermostat.

    The other thing to remember is that a PID cant compensate for the group head design. It wont show how successive shots get hotter and hotter. As long as youre only pulling one shot after a heap of rest, there will be no difference and I would guess that the variation between shot 1 and 2 might even be negligible. Especially if you flush before shot 1 ... but then you have to wait for the boiler to restabilise ...

    Anyhoo, all that Im trying to point out is that it is very difficult - and, indeed, dangerous - to reduce espresso to numbers.

    Cheers,

    Luca

  42. #42
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    Re: Espresso temperatures

    Yes Paul, they are shocking figures. Silvias deadband lets it down terribly.

    BUT---

    Luckily the chunky group and portafilter are there to smooth out much of this variation.

    The temperature at the top of the boiler is about 15 hotter than at the shower screen. The boiler is inside the machine, with a 300ml capacity. The element makes it overshoot, and the inrush of water during extraction will cool it rapidly.

    But down below, more stable dynamics are at play.

    The group is outside, in the open air, and has a relatively much larger mass which means it runs cooler but more stable temperature.

    So even though water in the boiler is wildly fluctuating, as it emerges into the basket--- which is surrounded by a lot of thick brass--- the biggest influence will be the group.

    If you search through google alt.coffee threads, there has been much done on this, the upshot is that temperature is kept steady within one or two degrees during the 30" extraction.

    So its not all doom and gloom.

    A PID, of course, will keep everything more steady.

    --Robusto

  43. #43
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    Re: Espresso temperatures

    It would be interesting to try to mount the probe on the pipe feeding the showerscreen.

    I absolutely agree that you cant reduce everything to numbers, but hey, it IS part of the fun (for some), after all I could go down to Whithams Cafe in Waverton and get a pefectly good coffee for 4 bucks :D but where is the fun in that?

    Anyway, I am enjoying the coffee while I am looking forward to the PID arriving.

  44. #44
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    Re: Espresso temperatures

    Behmor Brazen - $249 - Free Freight
    Hi again All,

    The thing with PID Control, when it is taken in isolation and with the rest of the system not optimised for this level of control, is that it too has severe limitations. Sure, it will allow for a fantastic level of control in maintaining a Steady State temperature of the Boiler water but since the Brew System hasnt been designed with PID Control in mind, it is very difficult to achieve real meaningful control of the Brew Water Temperature as it hits the coffee puck.

    Even if you sited the Feedback t/couple bead right in the Group Head, all this will do is to provide for initial correct Brew Water temperature at the instant the Brew Switch is actuated. Because of the Thermal Inertia of the system and the Brew Water Path through the Boiler, there will be significant delay before the water shows signs of responding to the call from the Controller to start heating up again. What this means, is that the Brew Water Temp will show a continuous decline in temperature most likely well after the shot has been poured.... Such is the Thermal Inertia of the system.

    Siting the t/couple bead close to the Cold Water Inlet at least allows for a reasonably quick response in that the inrush of Cold Water presents a pseudo Feed-Forward element into the control. By setting the PID Setpoint such that the water temperature hitting the coffee puck is close to ideal, the effect of the Feed Forward effect of the Cold Water rushing in, is to throw the Process Variable out to the limits of the Proportional Band almost immediately, thereby causing the Controller to call for close to 100% output of the Heating Element within seconds of hitting the Brew Switch. By paying judicious attention to the PID parameters, it is then possible to setup the Controller so that it not only responds very quickly to pulling shots but will also keep Overshoot to a controllable minimum. In the case of the Mokita for example, the Boiler Water Temp was restored to Setpoint equilibrium in 90 seconds or less. This number will vary from machine to machine of course since Thermal Inertia and Brew Circuit Design will also vary.

    I hope this is of some help to budding PID Control enthusiasts....

    All the best,
    Mal.



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