The age old backflush question

Post by **Barry** » Tue Sep 13, 2005 8:59 am

I am back to questioning the need to backflush the system assuming proper procedure is followed. First, if we assume (and this is a key point) that the double screens are effective at preventing any grounds from entering the group head, it is safe to say that only liquid residue is an issue. I have my single shot button programmed for a ristretto. I have my double button programmed to let about 4 ounces of water out of the system. After every ristretto I pull (and this is all I pull), I use the double button to flush any residue out of the group head. This will not flush the expansion valve, however, it should flush the area that comes in contact with the water that produces the shot. I remove the screens every morning after pulling two ristrettos to manually rinse them and the brass diffuser. Using this procedure, other than the small amount of residue that the expansion valve is exposed to, how is the actual group head area at risk of residue and in need of backflushing?

Post by **Barry** » Sun Sep 25, 2005 8:19 am

Okay, almost two weeks...do I interpret a normaly vocal group's silence as?

1. Agreement

2. We don't care!

3. Haven't we discussed this enough!

Post by **ishcoco** » Sun Sep 25, 2005 10:29 am

Barry wrote:Okay, almost two weeks...do I interpret a normaly vocal group's silence as?

1. Agreement

2. We don't care!

3. Haven't we discussed this enough!

I'm a NooB to this forum, and I'm sure we care, Barry

Are you referring to backflusing with plain water, or using Cafiza (or the like)? This seems to be a hot topic, particularly for this machine. I have owned several machines, and have always backflushed. Just b/c this machine has 2 screens doesn't mean that oils aren't still up there. I just got mine, and will backflush as soon as my new bottle of Cafiza arrives. I am certainly not an S1 authority, but this machine is really not that different from most. If I am incorrect in my thoughts, someone please correct me.

Post by **hlsheppard** » Sun Sep 25, 2005 12:28 pm

Personally, as another new owner, I vote for #4: I'm not sure...

I pull two doubles every morning, plus whatever I do during the early evening. After each session I use the blind basket to do the following:

1 - Run a few ounces of water through the grouphead (with no PF). My single shot button is programmed for about 4 oz. (or a manual pull), so I use that.

2 - A "portafilter wiggle" using the single basket with the rubber "blind" insert (usually at least two times).

3 - Two backflushes with water only.

I use Cafiza to backflush weekly with screens removed and soaking in Cafiza as well.

Funny thing is; since I've been doing that, I've developed a slow drip from my expansion valve (that most units have - but mine DIDN'T!

)

Chris would say (I think) that I'm over-doing it. I can't help the fact that I'm a tad obsessive about such things.

rhinoevans · Post by **rhinoevans** » Sun Sep 25, 2005 3:26 pm

I no longer backflush with Cafiza. I do the wiggle to clean the head of grounds after every pull. I clean the screens and disk every other month. Sometimes I do a backflush with water only every now and then. I do not know why I do this???

Post by **Barry** » Mon Sep 26, 2005 9:27 am

I am certainly not an S1 authority, but this machine is really not that different from most. If I am incorrect in my thoughts, someone please correct me.

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This is where I disagree. Most machines allow grounds to get up into the group head which create the biggest issue. In the year I have had my machine, I have never found grounds on the brass diffuser disk. I believe that an 8 ounce flush directly after a pull, removes all of the oil from the area where water that is used for brewing is in contact. It will not remove the oil that could build up in the pressure relief valve area, however, I would assert that this is really a non issue.

Post by **hlsheppard** » Mon Sep 26, 2005 5:55 pm

Didn't I read a stated from La Spaziale *somewhere* that said that you didn't need to backflush (just change/clean the screens)??

Not that I took that advice, or anything...

chas · Post by **chas** » Wed Sep 28, 2005 8:36 am

hlsheppard wrote:Didn't I read a stated from La Spaziale *somewhere* that said that you didn't need to backflush (just change/clean the screens)??

Chris told me that when he was visiting the LaSpaz factory last year they showed him their preferred way of cleaning and recommended against detergent based backwashes because they wash away the oils needed to lubricate some of the inner workings. This method is documented here: http://www.rimpo.org/s1/S1FAQs.html#backflush

I've developed my own hybrid process where I do a forward flush after each use while scrubbing the screen and the gasket area vigorously with this tool: http://www.chriscoffee.com/products/hom ... coffeetool while running the group. I've actually prgrammed the single doze button to dispense 4oz which I use during this process.

Then about once a month, I remove the screens and dispersion disk,, scrub and soak in cafiza, then I do a Cafiza based backwash using only 1/4tsp. If I were more conservative I might do this every other week, but the forward flush after each use works so well that monthly seems like enough.

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