jpender wrote:If that pitch black sticky tar-like gunk is really coffee then you must be brewing with an uber-French roast.

Bzzzzzt!

You just inspired me to make a quick shot with the Robot using Nossa Familia Teodoro's blend, which seems to be on the darker side of medium; it certainly isn't a French roast nor oily. FWIW I've only used medium roast coffee the last 4 years, and usually lighter than this.

Here's a photo of the beans under the same lighting (snake in background)



This is probably the darkest coffee I've ever used, and only had it a few times....

Here's just after brewing a few minutes ago:




After using the knockbox (the remainder goes down the drain when rinsing):



Inside under 6k halogen lighting:



FWIW coffee always looks much darker after brewing.

Anyway, I was hoping for photos of a clogged pipes

Not sure what that would tell you that the snake didn't reveal. Unfortunately I'm lacking an arthroscopic camera at the moment, so unable to investigate much further. I do know with certainty that the darkest stuff going down my sink has been coffee residue from beans ground for espresso.

DaveB wrote: FWIW coffee always looks much darker after brewing.

Fair point. But other stuff might also turn black in your drain.

DaveB wrote: Not sure what that would tell you that the snake didn't reveal.

If coffee was the cause or a contributor or an innocent bystander.

Thats a C+ if nothing else

jrham12 wrote:Like the OP, I use a knockbox but do rinse the portafilter in the coffee station sink after knocking out the old puck... As such, every other weekend or so, when we clean the sink with some barkeepers friend, I put the stopper in and fill the sink up with very warm water. Then pull the stopper to "power flush" the drain line... No idea if that is actually effective, but it makes me feel better!

I think you could be on to something here. When I snaked the drain the other day, I had a hard time because the snake I have on hand is old and has kinks in several spots, and was only able to feed approx. 6 feet. I wasn't confident that I'd sufficiently cleared the clog, so after I reassembled the P-trap, I filled the sink with 8" of very hot water, then pulled the plug. It drained for a bit and then stopped. For several minutes I contemplated my next move, and then suddenly it started draining again! I filled up the sink again and let her rip. This could very well be an effective anti-clog preventive measure.

Boiling water down the pipes every so often was an "old wife's" trick of keeping drains/pipes clear.

DaveB wrote:I think you could be on to something here. When I snaked the drain the other day, I had a hard time because the snake I have on hand is old and has kinks in several spots, and was only able to feed approx. 6 feet. I wasn't confident that I'd sufficiently cleared the clog, so after I reassembled the P-trap, I filled the sink with 8" of very hot water, then pulled the plug. It drained for a bit and then stopped. For several minutes I contemplated my next move, and then suddenly it started draining again! I filled up the sink again and let her rip. This could very well be an effective anti-clog preventive measure.

Every 7-10 days I pull a ltr or 2 of boiling hot water from the steam boilers of my machines & pour it down the bathroom sinks. This keeps the mineral content in the boilers down & washes the soap/toothpaste/hair scum out of the drain below the sink. If there is any sign of a partial clog I give it 3-4 pumps with a small bathroom plunger which clears the drain quickly.

Boiling water was somewhat useful to re-open this drain for a short while at a time, but it didn't fix the build up issue and the pipe eventually had to be replaced. Maybe works as a preventative measure if you do it from the start, but doesn't seem to fix a problem once it has developed.

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Looks like a very light roast.

slybarman wrote:Boiling water was somewhat useful to re-open this drain for a short while at a time, but it didn't fix the build up issue and the pipe eventually had to be replaced. Maybe works as a preventative measure if you do it from the start, but doesn't seem to fix a problem once it has developed.

Depends on your clog. Works well on a hair clog in a bathroom sink when combined with a plunger. Your clog reminds me of all the old plumbing I ripped out of our home. Most either "drained" slightly uphill or just ran flat so everything settled in the pipe instead of being carried out by the water. After I replumbed the entire house with the proper size pipe installed at the correct drain angle I've had no issues & I do rinse my PFs in the coffeebar sink.

Good eye. This pipe did have a bit of a belly to it. Not sure if it started that way or developed it because of the clog. It is also a long run across the width of the house and may not have as much slope as it ideally should.