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.
Christian B.