EM6910 v Silvia v the world!

[telemaster]

Re: EM6910 v the world!

I am not taking the p_iss when I say upgrade to what.  Realistically the next step up has to be a heat exchanger machine at what $1,400 min for say a Barazi....I am not saying that I wouldnt do it, mainly because I am a sucker for a new toy and they are a flash bit of kit, but its a big step....and I venture to say that you would want to taste one hell of a difference to really sit down at the end of the day and feel that it was another gorilla well spent!

Cheers
/\/
/\/PS.  Its such a good bargain at $400 a/ who cares about re-sale and b/because the intial purcahse price is so low versus ability, if you get $100 for it out of warranty one could not complain too...bitterly....(sorry...had to stick in an Austin Powers style punn).

Am I missing something here? I thought Barazi imported, serviced and sold Bezzera (which are wonderful machines). Is there a Barazi machine- couldnt get one on Google?
Brett

[telemaster]

Re: EM6910 v the world!

Question for Sparky or others- I thought that thermoblocks lost temperature quicker than boilers of a reasonable size. Is it viable to get a thermoblock reasonably temperature stable? Is the issue just the size or material of the thermoblock? I can see that an aluminium thermoblock would heat up quickly compared to a large 300-400 ml boiler but the temp drop during a pour could account for the sourness (maybe).
Brett

[JavaB]

Re: EM6910 v the world!

Brett,

Yes and no (hows that for hedging my bets ;D)

Yes, a thermoblock will heat up faster and cool faster than a boiler....

No, that "shouldnt" affect thermal stability because the smart electronics should be able to regulate the temperature within very tight limits..... and if that is the case the mass of the thermoblock isnt an issue (although of course a larger mass - either water in a boiler or metal in a thermoblock will have an inherently better thermal stability... making regulation easier- but not faster)

The question which is being debated (hence discussion re doing a temperature profile during a pour) is are the electronics in fact regulating the temperature within the close tolerances which they should be? - and that comes down to the design of these electronics and the placement of the temperature sensor.....

We will all know when Sparky or someone else actually does a profile.

[Wushoes]

Re: EM6910 v the world!

This is slightly off topic, and I asked similar question earlier but anyway...

Am having probs with the Sunbeam sometimes working out shot times etc with the pre-infusion. At work on the Wega we norm pull 1.5oz shots in 25-27 sec. After 5/6sec everytime the shots start to pour. So you cud say once the shot is pouring the shot takes 20 sec.

The Sunbeam from memory starts pouring at 13sec. The shot starts off pouring slower then the Wega at work, then ends pouring faster. I am pouring the same 1.5oz of coffee. The basket size etc the same.

If im extracting for the same length once the coffee starts to pour (or drip - 20sec) then with the Sunbeam the shot shud take 13sec + 20sec = 33sec?

Does the pre-infusion effect the ideal extraction time once pouring? Cos its pre-soaking the grinds? Maybe it makes the coffee pour faster because its already pre-soaked making extraction time still 25sec in total? (13sec + 12sec once pouring?) Though this seems v.fast?

Sorry this post is kinda long!

Thanks!

Jonno,

The preinfusion only takes a good 5 to 6 seconds max....and pretty much should start pouring straight away. It sounds to me like youve set the fineness of your grind too fine.

Even on a ristretto type pour for me, the Sunbeam does not take 13 seconds to pour.

[ozscott]

Re: EM6910 v the world!

(said with hooked pinky up to my mouth) Perhaps having a machine with such a long pre-infusion time would leave you with a....sour taste....in your mouth....


(Sorry - the kids are watching way to much Austin Powers and I of course watch it too...just to keep them company of course).....

[Wushoes]

Re: EM6910 v the world!

Well..the preinfusion isnt long...its just 3 short bursts of water on to the cake....then the pump resumes full operation.

You could certainly do a lot more on a manual lever machine

[Sparky]

Re: EM6910 v the world!

Question for Sparky or others- I thought that thermoblocks lost temperature quicker than boilers of a reasonable size. Is it viable to get a thermoblock reasonably temperature stable? Is the issue just the size or material of the thermoblock? I can see that an aluminium thermoblock would heat up quickly compared to a large 300-400 ml boiler but the temp drop during a pour could account for the sourness (maybe).
Brett

Water is excellent in storing heat, so boiler and heat exchangers machines utilize this fact for thermal stability. On the other hand a thermoblock doesnt store as much heat in a given volume, but it responds very quickly to changes in temperature. So an element can actively compensate for any drop in temperature during the shot. This is an active design that compensates for losses as they happen. So it should be able to hold a very stable temperature if the control protocol is implemented properly.

Cheers,

Mark.

[Wushoes]

Re: EM6910 v the world!

Well all this theory is just that. Id really love to use a SCACE type thermofilter to thermolog the group of the Sunbeam. We can speculate at what is causing the sour shots unless we actually rule out the shot temperature stability as the cause of it.....(which would be interesting).

Not all things are designed equal (take an extreme example of a Holden Barina vs Ferrari F50....both cars get us from point A to B...but how it gets us there is the issue)

[Kiwi_Jonno]

Re: EM6910 v the world!

Wushoes,

Just being making a couple cups of coffee...

Sorry I said 13sec earlier, before the shot starts to drip with pre-infusion. It was actually 10sec when the shot started. Still 4sec longer then the commercial machine.

Am still finding 32sec extraction for a double shot tho.

[ozscott]

Re: EM6910 v the world!

when the shot starts on mine - ie when the honey starts to trickly I shoot 25-30 seconds unless I have overloaded and tamped way to hard!


Cheers

PS. NO more Austin P from me

[JavaB]

Re: EM6910 v the world!

Well all this theory is just that. Id really love to use a SCACE type thermofilter to thermolog the group of the Sunbeam. We can speculate at what is causing the sour shots unless we actually rule out the shot temperature stability as the cause of it.....(which would be interesting).

Yep.... we need some real measurements.....

But just to add to speculation..... Aluminium conducts heat 26 times more efficiently than stainless steel....

So if the element is in the aluminium, and the temp sensor is also in the aluminium (almost certainly the case).... then even if the aluminium thermoblock is absolutely at constant temperature.... then the additional thermal resistance of the stainless steel lining of the water path would set up a thermal gradient between the aluminium block and the water inside the SS tube.... so the water would be at a lower temperature than the block whilst it is flowing (the same temperature - after a short period- whilst the water is stationary)......

Add that to "yet another crazy theory to be tested" :!!

[ozscott]

Re: EM6910 v the world!

telemaster - yep Bezerra is the machine sold by Barazi - typo. I tried a short black from the Bezerra at Barazi at Coopers Planes when I got the Rocky. I hope that it can pump out sweeter short black than I tasted there...

[Wushoes]

Re: EM6910 v the world!

Pushed brew temp to highest setting (+4 deg from default....92 deg? So 96 deg C) No sourness on my home roast png peaberry.

[Sparky]

Re: EM6910 v the world!

But just to add to speculation..... Aluminium conducts heat 26 times more efficiently than stainless steel....

So if the element is in the aluminium, and the temp sensor is also in the aluminium (almost certainly the case).... then even if the aluminium thermoblock is absolutely at constant temperature.... then the additional thermal resistance of the stainless steel lining of the water path would set up a thermal gradient between the aluminium block and the water inside the SS tube.... so the water would be at a lower temperature than the block whilst it is flowing (the same temperature - after a short period- whilst the water is stationary)......

Thats always the case, regardless of the lining of the thermoblock. Heat only flows if there is a temperature gradient, so the set temperature is approached asymptotically. The thin SS tube wont have a dramatic effect on the operation and has other advantages. A copper tube would be better, but it might not have been necessary. The rapid response Ive observed suggests this is the case.

Im ready to thermolog one of these beasts. I just need the machine with a naked PF.

Cheers,

Mark.

[Wushoes]

Re: EM6910 v the world!

Where are u located?