stuff from HERMS coil

[Arbe0]

I have a HERMS coil that everytime I clean it lateley or brew with it there seems to be a lot of what looks like grain flake residue that come out of it. I clean it every time after a brew with PBW and sanatize with Starsan, I have had this for many years but in the last few months this has happened. But now I am not sure what this stuff is that I cant seem to get rid of. Could it be left over grain or maybe the HERMs coil is loosing some kind of layer of something inside.

 

[day_trippr]

If the coil was fabricated using stainless steel I can't see how that isn't just dried wort.
If it's copper I suppose it could be corrosion products but even that seems like a stretch...

 

[sibelman]

layer of something inside

The appearance of the flakes suggests that, over time, some residue has survived your cleaning efforts and accumulated in there. This suggests a more extreme cleaning is needed.

You may get some better results by cleaning first with an alkaline solution like PBW, and then an acidic solution of some kind. Heat also helps. If you try this, be sure to rinse the acid out when you're done.

fwiw, I send hot water through the coil right after the mash, and then (generally the next day) recirculate hot (~150°F) Oxiclean solution through the HERMS coil for 20 minutes, let it sit in there for another 20, then rinse with hot water. I haven't seen crud emerging.

I hope you can get this thing all cleaned out, @Arbe0. HERMS and counterflow chiller coils can hide stuff, which is definitely a worry.

 

[whoaru99]

Maybe you could push a small/moderate size soft copper wire through the coil, put a PBW-soaked swab into a loop on end of wire then pull it through. Swab should be pretty decent friction fit, but not so tight as to get stuck trying to pull it through.

 

[day_trippr]

I recommend recirculating hot (150°F) pbw solution, something I do to my 50' herms hex coil every couple of brews...

Cheers!

 

[Deadalus]

One or two of those bits look like grain hulls. It looks like perhaps something dried and then flaked off. You could give it a taste if you were feeling bold!

I run hot PBW (also 150F) through every time, then rinse with hot water, then starsan. I create a long loop from my BK to the pump, then through my CFC over to the HERMS coil then back to the BK. I let it empty into my hop spider and it catches bits of stuff. Twenty to thirty minutes. It's a good idea to do if you have a plate chiller too, perhaps reversing the flow initially. I leave the BK power on about 10-15% so the the PBW stays warm. Once in a while I may let it run longer.

 

[Deadalus]

Maybe you could push a small/moderate size soft copper wire through the coil, put a PBW-soaked swab into a loop on end of wire then pull it through. Swab should be pretty decent friction fit, but not so tight as to get stuck trying to pull it through.

If you tried this, you can tie a cotton ball or 1/2 of one to a string long enough to get through and then use a shop vac. Make sure the string is tied to something on the far end. The shop vac will suck it through almost instantly. I've done it a few times for electrical conduit and ethernet conduit. I then pull the fish tape through back to the other end and fish the wire through. So you could pull through a more solid wire with whatever you think might work to clean the sides. I'd try what @sibelman mentioned first though, I've seen that recommended before.

 

[sibelman]

I've never tried pushing/pulling anything except liquid through a long coil. (Conduit with a few bends seems quite different.)

My HERMS coil is 50 feet. OP's?

It's an appealing thought, trying to get some scrubbing action going. I'm envisioning a brush on a 25 foot stiff-yet-flexible fish tape. But it's so curved! It seems intuitively likely to end badly with something stuck in there.

 

[whoaru99]

Given the relatively robust nature of the coils, even if a swab came off, I'd envision a good blast from air compressor would make short work of clearing it.

At work the production facility uses special compressed air tools to shoot foam "bullets" through steel tubes/hydraulic lines to spot check for contamination before they are put into a system. We have found despite having cleanliness specs on the part requirements provided to suppliers, it's good to keep'em honest.

 

[Deadalus]

About 25 years ago I built a 50' counterflow chiller. I didn't know about pumps and couldn't have afforded one anyway. It was 1/4" soft copper and I cleaned it once maybe twice by pulling a cloth or cotton ball through it. Then I promptly converted the copper to an immersion chiller! It's usually the fittings that I find the fish tape gets stuck on. It'll catch the pipe end inside the fitting (using street fittings there can help some). The flatter tapes don't twist well either and can get bound up in the turns. Something flexible like a small chain or thin wire is easier but you can't push those through. Plus you can't really see inside so I do my best to never have to clean it like that. Not as much worry on the HERMS coil as it is on the hot side but I have a CFC again. Both coils are 1/2" and bigger than my old IC/CFC. My HERMS coil is 50' but my new CFC I think is only 13', it's the fat copper style.

 

[Arbe0]

ok.. this is what I have done. In the past after every brew I used boiling water to go though every pumps, pots, and coil right after the brew was in the fermenter. My thought was all the wort was still watery and it shouldn't dry in the coil. If I got grains in there (which i never thought I did) I would havc thought the grains would be pushed out. I also cleaned with PBW a few times in the past but not all the time.
Yesterday I ran filled my boil pot with 150 f water and good amount of PBW and ran this though the coil using a pump and catching the gunk in a hop spider. I let it sit for 30 minutes after recirclating for a while, after 30 minutes I started recirculated it again though the HERMS coil and into the boil pot, catching gunk in the hop spider, I did this twice. I got a lot and it seemed to help switching the hoses. I then used clean hot water to clean out the boil pot and filled it again with hot water to clean out the pump, hoses and the HERMs coil, which I drained the best I could. Today I did the same thing and got even more gunk. It i hard for me to beleave this was all grain flakes but it just might be. If it is not from the grains I think it is from the coil, maybe some kind of plaiting coming off from the inside. I dont remember where I got the coil but it may be just a cheap one that I am having a problem with. I have used this coil for at least 3-4 years and this has just started to do this about a month ago.

 

[mashdar]

Reminds me of the biofilm that was growing in the airpots (insulated coffee dispenser) at a former office. Whatever it was could survive hot coffee temperature well enough to keep chugging.

Do you ever run boiling water through it?

 

[Arbe0]

Reminds me of the biofilm that was growing in the airpots (insulated coffee dispenser) at a former office. Whatever it was could survive hot coffee temperature well enough to keep chugging.

Do you ever run boiling water through it?

yes I always ran boiling water though all the hoses pots Herms coil and chiller into the sink; every time I brewed right after it went into the fermenter.

 

[Arbe0]

this is how I solved the problem: bought a new Blichmann HERMS coil and installed it , took apart and cleaned all pumps, ball valves, hoses etc with PBW then used Starsan to sanatize . the ball valve in the boil pot and the pump after that had lot of nasties in them but now are squeaky clean and shiny. Home brew system now all clean and ready for another brew.
The old HERMS coil I am trying to get it clean while it is out of the HLT hoping to have it for an extra if I can get it all clean..
Final thought: clean system for often, don't wait a year to clean it