does anybody know how to change brewing temp on a vibiemme?

[luca]

it seems that no matter what I try, it's very hard for me to get a consistent dark crema. most of the time I have to cheat and use a double dose basket for one cup. differences in tamping and grinding with my Rocky do make a difference of course but even with ideal grind and tamp it's hard to achieve a dark crema. I also tried dozens of different kinds of coffee, from freshly roasted to wooden roast commercial blends, but still unsatisfied.
i am starting to think there must be something wrong with my machine, maybe brewing temperature too low (although the grouphead gets really hot and I can see steam coming out of it when I flush it).
how do I check and change the temperature in my machine?
could it be anything else?
thanks.

[jumper]

is it a proffesionel machine?

[phil]

I'm assuming you just have a standard Domobar, Luca. Is that right?

[luca]

yes, the standard one. I found out that there's a small screw that's visible only if you remove the cupwarmer and if you turn it to the right the temperature gets higher. but I tried to turn it a bit and the first time I tried to flush, there was so much steam coming out of the group that I turned the screw to the left again. so, maybe the problem I had at the beginning was that the temp was too high and not too low? how does a too high temperature affect the crema?

[zix]

how does a too high temperature affect the crema?

Well, it sure affects the extraction anyway. Just push the steam button, wait until temperature is high enough to steam milk, lock and load your portafilter and try to pour a coffee shot. Steam will burst out through every little leaky place between the gasket and the portafilter. I am not sure this is good for the machine either... not much coffee will end up in your cup, and what there is will taste more bitter.
I have never let it run for a full 30 seconds to compare crema, (naturally, since the few times it has happened it was a mistake...), but in the small amounts that have gotten into the cup, there has been almost no crema at all. So I should expect you get less crema if the temp is too high.
I don´t know the temp limit for crema though, or if the limit is sharp and well-defined or "blurry".

[michel]

Luca, a too high temperature kills almost all crema!!!! So... turn the screw to the left for G. sake... About a quarter and see how it affects your shots!

Michel
(who is very happy with his low-temp-Giotto... although frothing is a bit difficult the shots are marvelous!)