Crud inside screen - how come?

Bill Laine

New member
Jan 5, 2008
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New Orleans
When I clean the screen from the grouphead on my Silvia there is a _lot_ of greasy brown crud on the inside of the screen. How does it get there. It is only clean water passing through and the flow and pressure is going the other way.

Is it some kind of turbulence during extraction?

Is the crud something that needs to be cleaned out or is it an 'essence' that would add to the cup?

Bill
New Orleans
 

JohnB

New member
May 30, 2008
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Connecticut
I would imagine that you are seeing coffee grinds & this will happen on any Espresso machine. Water is hitting the puck at 9 bar (ideally) so some of the grounds are bound to get up in there. If you tend to overdose you will probably see more.

I drop the screens on my Vivaldi once a week for a good cleaning. Are you doing plain water backflushes at the end of each day?
 
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Bill Laine

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Jan 5, 2008
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New Orleans
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Backflushing Silvia

JohnB said:
Are you doing plain water backflushes at the end of each day?

No, no backflush. Lots of internet "experts" say "don't pay any attention, go ahead and backflush your Silvia." The guy that sold me my machine says "NEVER BACKFLUSH." Since he services the things I pay a little more attention to the sellers instructions.

But it's a good question. Why the divergent opinions? What is vulnerable when you backflush a Silvia?

Bill
New Orleans
 

Randy G.

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May 8, 2008
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California
The Silvia is equipped with a 3-way valve. I explain its operation in great detail here:
http://home.surewest.net/frcn/Coffee/3way/intro.html
This article includes details as to how the crud gets up in there.

Yes, the machine needs to be cleaned occasionally by disassembly as well as backflushing. The instructions for backflushing are here:
http://home.surewest.net/frcn/Coffee/Ho ... flush.html

Check out my website as there is a lot more there besides these two articles:
http://www.EspressoMyEspresso.com
 

JohnB

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May 30, 2008
113
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Connecticut
I've never owned a Silvia but if it has a 3 way valve I see no reason that you couldn't do plain water backflushes. Maybe your service guy was concerned about backflushing with a cleaner like Cafiza?? That is something that only needs to be done once every month or more.
 

shadow745

Active member
Aug 15, 2005
1,585
2
Central North Carolina
I totally agree with backflushing any machine with a 3-way. For awhile I didn't do it to my machine and it was rather nasty once I did it and couldn't believe how much crap came out of that pathway. Even though I strip the parts from the grouphead every 2 weeks it will still find a way to buildup and affect flavor. I'd say backflushing at least once weekly with water alone is fine and maybe once every month or so with detergent is OK. I use JoeGlo and it works great and extremely fast. Be sure to backflush with water very well after the detergent and remove your shower screen and scrub it and the other parts (portafilter, baskets, etc) before re-assembly. Be sure to use some old beans to run 1 shot through to season it properly. Later!
 

CCafe

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Aug 11, 2004
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Des Moines, Iowa
JohnB said:
I've never owned a Silvia but if it has a 3 way valve I see no reason that you couldn't do plain water backflushes. Maybe your service guy was concerned about backflushing with a cleaner like Cafiza?? That is something that only needs to be done once every month or more.

Anytime you make an espresso you need to backflush with cleaner before you shutdown the machine. Water will not break down coffee oil. Espresso cleaner is formulated to do so.

Take a shower head out of a machine after a month of usage. Soak it in a cup of hot water and cleaner. I gurantee you it will foam up and out of the cup. That is what the cleaner is designed to do.

If you take apart that 3-way valve you will notice that the plunger has a spring around it and keep it in the closed position. Overtime the oil and residue will build up and rust it in a closed, semi open, or wide open position.

Normally I find them in a closed position but sometimes you get a coil with a enough pull to break it open then it will never close again. So save yourself the trouble and buy $10 bottle of cleaner vs $80 valve.

If you want to see proof I'll be more then happy to send you 5 gallon bucket full of crapped out valves!
 

JohnB

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May 30, 2008
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Connecticut
CCafe said:
Anytime you make an espresso you need to backflush with cleaner before you shutdown the machine. Water will not break down coffee oil. Espresso cleaner is formulated to do so.

T

You do a plain water backflush on a daily basis to clean any grinds/debri out of the system. Backflushing with cleaner daily or even weekly is unnecessary & can damage the parts you are cleaning out. La Spaziale doesn't even recommend using cleaner but the U.S. distributor suggests a backflush w/cleaner session once a month & no more often then every 3 weeks w/plain water backflushes daily or weekly.

If you flush daily the 200*+ water will certainly remove some of the fresh coffee oils from the system. If you have neglected any form of cleaning then starting with a cleanser backflush would be a good idea to get the old oils out of there. Be sure to backflush with clean water until all signs of the cleanser are removed then pull a shot & dump it in the sink.
 

Davec

New member
Oct 18, 2006
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Old England (UK)
Definitely backflush with cleaner every 4 to 6 weeks depending on how often you make coffee. Also nightly a clean water backflush is advisable.

The main reasons the manufacturers get a bit wary of backflushing, is that people rarely lubricate anything after a backflush. Lubrication is necessary on a regular basis, especially when you use cleaner....problem is people generally don't know what to use, or how to use it.

With my E61 group I lubricate the cam and followers (valve stems) every 2 months or so.....the 3 way electrovalve "probably" likes to be lubricated, unless they have managed to change the laws of physics, or made a sealed unit that can't be lubricated. The only question is where and what should you use. e.g. nothing silicon based if the valve seals are silicon, luckily the valve seals should usually be be Viton or a rubber of some kind...so silicon (dimethicone based) could be used.

P.S. Luckily I have only one machine with a single electrovalve and as it's a 3rd backup machine, it's rarely used. I will get around to tinkering with the electrovalve to lubricate it in the next few months though.
 

Randy G.

New member
May 8, 2008
203
0
California
Re: Backflushing Silvia

Bill Laine said:
No, no backflush. ... The guy that sold me my machine says "NEVER BACKFLUSH." Since he services the things I pay a little more attention to the sellers instructions.

IMO- any "expert" that tells you not to backflush a machine with a 3-way valve:

- doesn't trust their customers and doesn't want to deal with warranty problems from people who damage their machine by leaving it running with a blind filter for ten or fifteen minutes at a time
- or -
- doesn't have a clue as to how an espresso machine works.
- or -
- doesn't know what they are talking about, and only are experts because they tell you they are experts.

have the guy read this:
http://home.surewest.net/frcn/Coffee/3way/intro.html
and then feel free to have him contact me. I would be glad to discuss any part of it that he might find inaccurate. That article was reviewed by one of the most respected and knowledgeable espresso machine repair persons in the world and approved as accurate.

If he can't be bothered to read it, read the following to him over the phone angd get his comments:
Form the above linked article:
---------------------------------------------------------------------
Can't the machine be damaged by backflushing?
As you have learned from this series of images, backflushing does basically the same thing as when you choke the machine with too fine of a grind, and it is basically the same as when you turn on the hot water switch, causing the pump to operate before you open the hot water valve. In either of those cases, the overpressure relief valve opens and allows the excess pressure to be relieved back into the water reservoir, protecting the pump and other components from damage.
If you use a bit of common sense, backflushing is no more damaging to your machine than choking it. Quite the opposite can be said to be true, because when the machine is choked, the home barrista will often allow it to run in that states for ten or fifteen seconds waiting for something to drip forth from the portafilter. When backflushing, the pump needs not labor for more than one or two seconds before being switched off to allow the 3-way to open.
If the machine is damaged from over pressure when backflushing then it was about to fail anyway. If a boiler seal is blown when backflushing it was about to go and would have failed from the next choked shot if not before. If a pump fails from proper backflushing it was just about to fail anyway.
-------------------------------------------------------------------

Among people who really know espresso machines there is NO divergent opinions about backflushing.

here is another point of view- a person who makes money repairing machines tells you to not backflush ever. After two or three years the machine becomes clogged and the 3-way valve stops operating. The machine, now out of warranty, needs to be repaired. Who benefits now? The guy charging you to clean a machine that he told you not to keep clean nor properly maintained.

There are lots of opinions about backflushing. I do not mean to sound pissy, but at least I back my opinions up with facts and scientific evidence.

I also do not sell anything nor do I get paid for repairing machines, so I have no personal interest in this subject other than wanting you to get as much life out of that machine and to make the best espresso you possibly can.
 

CCafe

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Aug 11, 2004
1,557
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Des Moines, Iowa
I'm not going to sit and argue with you. I do make my money by repairing machines. Except I tell people to backflush with cleaner on a daily basis. I don't care if you make 1 espresso or 500 a day.

Hell even your article tells you to backflush with cleaner (He likes Urnex Cafiza) I sell a lot of that too. I wouldn't ever recommend backflushing without cleaner.

A long time ago I saw a display where someone ran a red oil dye through a 3-way valve and then tried to flush it out with plain water. For the sake of his demonstration he flushed the valve several times with plain water. He pulled the valve out and disassembled it and you could still see beads of red dye inside the valve.

Then he repeated his demonstration but on the rinse cycle he ran the cleaner through only once. Upon examination of the valve it was completely clean inside. That red dye represents coffee oil and it will build up over time.
 

JohnB

New member
May 30, 2008
113
0
Connecticut
CCafe said:
Then he repeated his demonstration but on the rinse cycle he ran the cleaner through only once. Upon examination of the valve it was completely clean inside. That red dye represents coffee oil and it will build up over time.

The coffee oils work as a lubricant for the mechanisms which is why some machines can become noisy immediately after cleaning with a detergent but quiet back down after a few shots. A little oil in there is good but as you say it can build up "over time". This is why you use a cleaner once a month.
 

Randy G.

New member
May 8, 2008
203
0
California
CCafe said:
I'm not going to sit and argue with you. I do make my money by repairing machines. Except I tell people to backflush with cleaner on a daily basis. I don't care if you make 1 espresso or 500 a day.

Hell even your article tells you to backflush with cleaner (He likes Urnex Cafiza) I sell a lot of that too. I wouldn't ever recommend backflushing without cleaner...{snip}...

I am a bit confused... Are your comments aimed at me? If so, I don't understand since you seem to be agreeing with my comments and article. As far as backflushing, I have long supported it. For home backflushing, doing a clear water backflush will clear out coffee particles, but I agree that it does not cut the oils.

In teh home, E61 brewheads should not be backflushed daily with a detergent since, as you mentioned, the oils are need for lubrication on some of the internal parts of the brewhead, and accelerated wear of parts will result.

I am off to be confiused by someone else... :lol:
 

JohnB

New member
May 30, 2008
113
0
Connecticut
Randy G. said:
In teh home, E61 brewheads should not be backflushed daily with a detergent since, as you mentioned, the oils are need for lubrication on some of the internal parts of the brewhead, and accelerated wear of parts will result.

I am off to be confiused by someone else... :lol:

You are confused because I posted that info not CCafe. :? We all agree that backflushing is good & using cleaner is sometimes required, its how often you use it that we disagree on.
 
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