Cleaning Copper Stills without CIP

[CDS]

I have one all-copper pot still and one stainless boiler with a copper column. Neither have a CIP system so I have to disassemble to clean with a low concentrate citric solution. 

Just about everything I've read says to not use abrasive material to clean the copper components. The issue I'm running into is over time, I'm having to put more and more elbow grease to achieve the same results and it seems like using a mildly abrasive scour pad would make my life a lot easier. Any thoughts on this?

Also, how often do you clean your copper with citric? I'm wondering if I'm not doing it often enough because it's such a time-consuming task.

[SlickFloss]

Do not use an abrasive pad on the copper it will compromise your unit

 

citric washes over time will lower the life expectancy of your still

 

what you’re having trouble getting through is likely lipid residue that isn’t as soluble in acid

 

i have Learned over time a super low concentration caustic is as safe/risky as a rinses with low concentration citric. 
 

get some fucking spray balls  a lower power pressure washer will likely work better than citric if you’re needing elbow grease  shouldn’t need elbow grease except for severe charring/burning issues 

to be honest in working all over the industry (large small brewery fuel operating and now owner operating) I have found the only people to use citric so liberally and often are crafties, it is rather odd. Big Kentucky cleans ALOT LESS and rarely ever with citric. 
 

just my .02. Don’t have to take it and it’s from decades of experience, so I’m comfortable with our processes and procedures. We consult for distilleries and if you’re ever interested in short term consultancy or a distilling boot camp at our facility holler. Cv available. 
 

please don’t quote old posts where I Rec never caustic always citric, life is a journey and I’m learning and sharing unabashedly as I go. 
 

cheers 

slick 

Edited July 11, 2022 by SlickFloss
Clarity

[AK2]

Agree with Slick Floss, I use a low concentration (2%) of caustic.  Works a lot better if I heat it up.  Not too hot, maybe 130F.  I set up a recirculation loop and let the caustic do the work.  I do use a really low citric concentration after a gin run to get the still clear of some of the botanicals, but now that I think about it I bet that is not necessary (just one of those things you started doing and never examined why).  I flush with water before the caustic wash, and flush again with water after.  Again, not sure a double flush is necessary, just seems like the proper thing to do.  

Adam

[SlickFloss]

I struggle with suggesting concentration volumes with people who aren’t consulting clients from a liability standpoint but for that Schmutz-y lipid layer we’ve been able to work down to under 1% caustic solution with great results. 2% really didn’t cause pitting either. 
 

anytime you’re seeing as much copper suspended in solution as you do from a 30 minute 2-5% citric CIP loop (sky blue) that shit came off your still, thats a fin3 layer completely just rinsed off the entirety of the inside of your rig in solution. I understand the benefit of rejuvenating copper so it can absorb more S, but to have your only cleaning protocol be a citric rinse and to do it after every run, you’re really eliminating life from still. I can attest to bankruptcy purchased equipment that stills that were only cleaned with citric for years vs caustic for years are essentially pickled.

 

just my .02!

slick

 

 

 

[Brewstilla]

Does citric actually remove a layer of copper? Doesn't citric react with and dissolve copper oxide, not the copper itself, leaving the solution a blue color?

[adamOVD]

@SlickFloss Why not PBW? I feel like it cleans proteins as well as caustic.

[SCLabGuy]

8 hours ago, Brewstilla said:

Does citric actually remove a layer of copper? Doesn't citric react with and dissolve copper oxide, not the copper itself, leaving the solution a blue color?

I'm sure someone with more chemistry knowledge will chime in here but copper oxide is composed of copper - right?  It stands to reason that you are losing some pure copper to form the copper oxide layer.  So when you blow away that layer, more copper will end up consumed in creating the next oxide layer.

 

5 hours ago, adamOVD said:

@SlickFloss Why not PBW? I feel like it cleans proteins as well as caustic.

PBW is a caustic.

[SlickFloss]

PBW is caustic like home boy mentioned. Caustic is a general term for any basic ph cleaning chemical but often we deduce it to mean sodium hydroxide. It’s absolutely another option, just be sure to follow manufturers protocols for it. PBW when Mishandeled can also be catastrophic
 

we had a pretty dicey operator come through a facility I worked in a few years ago before my own shop. Dude would leave citric rinses on over night and even over weekends. Clearly a poor decision. Citric at super low and precise concentrations for specific purposes in moderation totally fine. But excessive exposure times cycle times and concentrations is trouble. 
 

Have a Carl still that basically uses copper bell caps for drains, still has only ever been cleaned by citric before we got it. The bell caps are cast and should be identical. None of them are the same weight, they all have pitting and corrosion issues and a lot of them have suffered bronzing (pickled). 
 

do whatever you thinks best. But if you want pictures of those bell caps and what 14 years of daily citric rinses does to a still get at me. 

[SlickFloss]

@Brewstillavendome would never reccomend that you use it to clean their stills 

 

@adamOVDpbw works it is caustic see above forgot to tag you (just leaned how)

[SCLabGuy]

I also know of operators who misused citric with disastrous consequences. Seems like it's usually coming from wine production. It's like I always say. "different things are different." 

[adamOVD]

Thanks for the clarification @SlickFloss  @SCLabGuy

I always wondered how they could put non-caustic all over the label and sales material when it is alkaline. Suppose it is under a certain threshold. Sorry to hijack the post.

[SlickFloss]

5 hours ago, adamOVD said:

Thanks for the clarification @SlickFloss  @SCLabGuy

I always wondered how they could put non-caustic all over the label and sales material when it is alkaline. Suppose it is under a certain threshold. Sorry to hijack the post.

No your good and it’s totally applicable not a highjack. I think they say not caustic because it isn’t sodium hydroxide. 

[jocko]

Just seeing this.  What is the recommended PBW/gallon to get a 1% solution?  I went to 5 star's web site and can't see mixing guides outside of "1-2 ounce/gallon"