HX machine problems- Brugnetti

[RobertC]

Hi al
I`m feeling like a complete beginner. I have just purchased a used Brugnetti Simona top machine to replace my Sunbeam EM 6910. It has become apparent that its functionality is far different to the EM6910. I`ve adjust grind & tamp pressures but it all just coming out like crap. Slow pours and it tastes bitter I`ve ground fine and coarse but still no good. Can some explain cooling flush, i`m thinking maybe this is the issue, is this no knock the steam out of the pour before it starts? Any help & tips would be appreciated. Also about every 20min the pump start and runs for about 5sec is this just topping up the boiler.
Rob

[burr]

I would recommend reading "how I stopped worrying and learnt to love HXs" as a starting guide. Yes, you need to do a cooling flush. There are two methods: long flush, dose and go; or short flush and go immediately.

The pump automatically refills the boiler in cases where water is removed i.e. after steaming, but if it is sitting idle I don't think it should need to. Also, as a guide what is the range of pressure in your boiler?

Well thats all I know, someone who has mastered the art of HX might want to give their two cents.

[RobertC]

Read the article and I think it makes sense. The pressure in the boiler when idle cycles between 1.4-1.5. As for the pump coming on when idle it has not done that today. I did only get the machine yesterday so hard to say if it happens all the time.

[burr]

If you haven't already it might also help to do a chemical backflush. I've found with some old machines when users don't backflush with detergent (i.e. cafetto) the shots suffer. 1.4-1.5 sounds high but this depends on the machine. Perhaps the Brungetti has a short path through the HX and compensates with a higher temp boiler?

[chokkidog]

It appears that Brugnetti factory settings are way too high.

Adjust the pressurestat down and try a couple of settings......... 1.0-1.1, 1.1- 1.2, 1.2-1.3

[RobertC]

Backflush is the next thing on my list. My Sunbeam had an automatic backflush cycle so how many times through would I do a backflush and for how long each time?

[RobertC]

Without sounding like a total noob does pressure relate to boiler temperature ? I did a cooling flush and checked the water temp and it levelled out at about 92 Deg I read that 95 deg is the desired brew temp?

[TOK]

Yes boiler pressure does relate to boiler temperature, but there are other things that also relate to brew temperature...

95 is invariably too high...I dunno where you read that. A fluctuation of say 88 to 92 would be considered to be within spec.

[RobertC]

Tok. I read that from the link that Buur had posted above Here is the extract.

"In the case of most U.S. espresso lovers, their target brew temperature is around 201-203°F; for some countries overseas, the tastes are for a cooler 192°F."

[chokkidog]

Without sounding like a total noob does pressure relate to boiler temperature ? I did a cooling flush and checked the water temp and it levelled out at about 92 Deg I read that 95 deg is the desired brew temp?

Where and how did you measure 92°C?

Yes boiler pressure does relate to boiler temperature, but there are other things that also relate to brew temperature...

95 is invariably too high...I dunno where you read that. A fluctuation of say 88 to 92 would be considered to be within spec.

Agreed TOK, but I would squeeze it out to 90°C- 93°C so that the mid range is about 92 +/-. My opinion only;....... I've had some great coffee tasting pretty awful at 85°C and start
to get twitchy at anything sub 90°C. ;-D

[RobertC]

Measured 92°c with the probe up the portafilter spout.

[TOK]

Agreed TOK, but I would squeeze it out to 90°C- 93°C so that the mid range is about 92 +/-. My opinion only;....... I've had some great coffee tasting pretty awful at 85°C and start
to get twitchy at anything sub 90°C. ;-D

Yes, 92 +/- is my "standard" and I also don't like to see it below 90 (and I use a *PID* BFC Junior Extra machine for cupping so easily managed), however a reasonable fluctuation for an HX machine would be between the figures I mentioned, where in reality you don't really know anyway unless you go to the trouble of using a thermocouple in the accepted way.

95 degrees burns coffee no matter which country you are in except perhaps where the particular ethnic custom is to use hard / very dense beans such as robustas or some of the indonesians for example, however this is not really for newbies to worry about

[burr]

Ah, a quick google search shows that the settings leaving the factory can be quite high (up to 1.5-1.65 Barr!) which is intentional due to the short HX path, but the manual recommends 1.3-1.5.

[tristanp]

Hi al
Also about every 20min the pump start and runs for about 5sec is this just topping up the boiler.
Rob

Hi Rob. The pump was recently running fairly regularly to top up the boiler on my machine too - and getting more often. I noticed a noise like steam escaping that used to happen as the machine warmed up was now constant. It turned out that there is a valve in the middle of the boiler top that had some corrosion. When the boiler warms up it pops up and stops steam escaping. However, with the corrosion it wasn't sealing and steam was constantly escaping - causing water to condense in the machine and also causing the pump to start more often.

Since I dismantled the valve and cleaned off the corrosion with wet and dry the pump no longer starts so often.

Could be something to check.

Cheers,
Tristan

[MrJack]

Sounds like you might be describing an anti-vacuum valve?