What a clear water backflush can('t) do... - Page 2

#11: Post by HB » April 13th, 2009, 9:06 pm

Elbasso wrote:I imagine that most of this was stuck somewhere in the lower valve and thus not compromising the flavor but still... Quite a shocking amount of old crud I would say. After seeing this, the chemical backflush has re-entered my cleaning routine and will probably stay there.

A fair amount of rancid oils were baked onto the grouphead's brass internals, especially the water jet breaker. It sounds gross, but I am mildly curious what a blind taste test of just water drawn through the group before and after cleaning would reveal. But not curious enough to intentionally skip cleaning for two months.

#12: Post by **malachi** » April 13th, 2009, 10:09 pm

Psyd wrote:I bet you clean far more frequently than they do in most commercial environments.

The "worst" coffee business I worked in did detergent backflushes daily.
The others all did either two per day or single groups every hour or so and a full breakdown and clean daily.

And that is with, as you note, far higher volume which does, in fact, make the issues less severe.

April 14th, 2009, 3:57 pm

Just out of curiousity, could you estimate the number of shots between each type of cleaning for each business?

Like I said, there is an advantage to some cleaning depending on MTBS. Those that get repetitive and continuous action should get a detergent flush every day, minimum, and those that get two or three shots a day should get a water flush at the last pull of the day, at a minimum (all IMHO).

#14: Post by **Fullsack** » April 14th, 2009, 5:04 pm

Remember to do a throw away shot, after any chemical cleaning routine, before making a drinkable one. If you ever had a little Cafiza in your shot, you know what I'm talking about.

After I do a clear water backflush, I insert the pf with an empty basket and run the machine for a few seconds. Adding this maneuver to the clear water backflush procedure removes additional spent grinds, can't say why, produces some sort of agitation, I suppose.

Edit: Do this procedure with a brushed and wiped basket and it will help extend the time between chemical basket soakings.

#15: Post by **malachi** » April 14th, 2009, 6:17 pm

Psyd wrote:Just out of curiousity, could you estimate the number of shots between each type of cleaning for each business?

Whew.... that's a hard one.
Ummm... I'd say the "daily cleaning" one ran at probably 100 to 200 shots between each detergent cleaning and probably 25 between clean water backflush (and quick brush down). I'd say that the others ran at between something like 40 and 100 shots between detergent cleaning. Those are per group of course.

Psyd wrote:Like I said, there is an advantage to some cleaning depending on MTBS. Those that get repetitive and continuous action should get a detergent flush every day, minimum, and those that get two or three shots a day should get a water flush at the last pull of the day, at a minimum (all IMHO).

Actually... higher frequency of use allows for less frequent detergent backflushing. Oil is oil soluble.

#16: Post by **cannonfodder** » April 15th, 2009, 1:30 am

Your tech may know the nuts and bolts of the machine but he does not know anything about coffee. Clean, clean often. I go through a pound, sometimes a bit more per week. I chemical backflush every Saturday and a water flush if I pull several back to back shots to help rinse off the group
Espresso Machine Cleaning, Why, How, and When.

#17: Post by **ChristianB** » April 16th, 2009, 11:22 am

HB wrote:It sounds gross, but I am mildly curious what a blind taste test of just water drawn through the group before and after cleaning would reveal.

I just did that experiment. I must confess that backflushing is not part of my daily or weekly routine, on the other hand I usually flush the group with a double shot of water before each shot I make, and flush the group again afterwards. I think the last time I did some serious cleaning was back in January when I also removed and cleaned the shower screen (I have backflushed with water since and maybe also with chemistry).

Before I started cleaning I filled a big cup with water from the group. After backflushing with chemistry, cleaning the shower screen and backflushing and flushing with at least 0.5l of water, I pulled a seasoning shot and filled another big cup. I filled a third cup after a few shots more and a fourth cup with the same filtered water I would put in the tank.

So now I had four cups:

0 "pure" water
1 before cleaning
2 after cleaning and a single shot
3 after cleaning and a few shots

I then left the cups to let them all get room temperature and then did a blind taste (three of the cups had some grounds in them so I needed to taste without looking). Here is what I tasted:

A significant off-taste, but not horrible, maybe plastic? [3]
B weak or no off-taste, good tasting. [1]
C somewhat between A and B, that is, also a little plastic taste. [2]
D weak no off-taste, good tasting. [0]

The cups are noted in brackets.

So basically I cannot taste the difference between pure water and water that passed through my machine -- that is a big surprise to me. Also, my guess is that the machine was probably pretty clean before I started cleaning it, and I did not flush with enough water afterwards.

April 17th, 2009, 9:17 pm

malachi wrote:The "worst" coffee business I worked in did detergent backflushes daily.
The others all did either two per day or single groups every hour or so and a full breakdown and clean daily.

That's interesting - my machine came to me second-hand, from a commercial environment, and my restoration of it showed me that they probably never cleaned it for the last 3-4 years they had it.

(I'm going by the water filter, dated 2005. The machine was born in 2000. I wouldn't be surprised if the only cleaning it had, pre-2005, and annual once-over by some 'engineer').

However, in my case, the 'commercial environment' i refer to wasn't a 'coffee business', but a pub. And IMO there have been days I've pulled more shots than the pub would have done...

#19: Post by **fxstsb** » November 8th, 2009, 3:26 pm

Elbasso wrote:About two months ago I had my Andreja serviced. It turned out that there was quite a lot of wear on the valves and the cam in the E61 group. When the Italian service guy heard about my regime to do a chemical backflush every three weeks or so, he went ballistic. According to him the group should NEVER be backflushed with chemicals. So, still trembling from the outburst of Italian fury, I decided to only do clear water backflushes after every session from now on.

Yesterday however I felt the sudden urge to live my own coffee life and decided to get out the chemicals and do a backflush with it. What came out totally baffled me:

<image>

I imagine that most of this was stuck somewhere in the lower valve and thus not compromising the flavor but still... Quite a shocking amount of old crud I would say. After seeing this, the chemical backflush has re-entered my cleaning routine and will probably stay there.

Cheers,

Bas

Looks like good beer!

#20: Post by **fxstsb** » November 8th, 2009, 3:33 pm

Is there a cheap inline water softener?