Funky bad karma, a rum disaster

[bfpierce]

I brewed a really nice rum wash and stripped it with good results via my pot still, the entire run was clear and the hearts tasted very good with a little carry over from the heads. tonight, I reloaded to make a spirit run using my column for a little better separation and after achieving equilibrium we went straight to disaster. the foreshots were clear and nose burning powerful and then the run started to put out some nice smelling, lightly rum flavoured (drops on the spoon) followed by a small column flood and full blown disaster, the distillate starting taking on a greenish brown and got progressively darker and foul smelling at which point I shut down and started researching ammonia, except when I opened the boiler after it cooled some, I smelled rotten eggs.

I loaded the still with crystal clear stripped wines 5L ~ 40abv with about a TBSP of kosher salt, the boiler's aluminum, stainless scrubbers and copper everything else. I'm only guessing that the reaction has to do with the salt or more likely the caking agent in it, I did a complete teardown and the scrubbers looked good but the reaction was definately with the copper, it's almost black! obviously I've done wrong somewhere and ruined a very promising 20L of rum wash.

any ideas where I went wrong and is there a way to clean up my still internals and return it to service or should I rebuild what can't be scoured completely?

sincerely,
Village Idiot (who's now donning his respirator to relieve himself of something funky smelling)

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[rad14701]

Wow...!!! I've never seen that much crap in spirits and also never seen that kind of separation in the boiler... The wash remaining in my boiler usually looks pretty much like it did when it went in and I've never had solids form and drop to the bottom...

[still crazy]

Im laying my money on stainless steel coated scrubbers
But they were steel coated/plated with a stainless appearing coating.

Dip em in vinegar and then no rinse with water see if they turn black before they dry

[Nightforce]

That is so weird. A similar experience happened to me just recently. First 4 gallon run of wash through my new 15 gallon keg boiler (had run 2 water runs with a vinegar run between them) did the same thing. Output was clear then slowed down and then puked out a similar greenish/brown awful smelling mess. I promptly shut down the heat, let the still settle down, cleaned up the mess and started over, but a lost slower this time. I chalked it up to more vapor being pushed up the column and flooding it but couldn't figure the reason for the greenish/brown mess as it should not have puked the contents of the still with all the extra volume in it. The column has a few stainless steel (solid SS) scrubbers and rashig rings so it shouldn't have tainted the distillate either. After it calmed down it worked good and distillate was clear.

[Barney Fife]

I've had bad SS scrubbers, too, with very similar results and an awful smelling, near puke-inducing stench when I opened up the boiler. That was a few years ago, but it's still vivid in my memory. Nothing but pure copper mesh now!

[bfpierce]

sorry for the late reply, life was in the way of play again.

I haven't checked my scrubbers as of yet but will soon, funny thing is, I picked them because they looked and felt identical to the stainless turnings from my lathe, I will let you know what the acid test shows.

I also learned a significant lesson about materials and construction, my column and condenser were just too difficult to clean. I just finished resleeving the condenser with larger tubing and will be building a new offset column in the coming weeks, all built in a way that makes cleaning much easier!

I'm also wondering if the salt may have promoted a galvanic reaction between the aluminum boiler and the copper column, the column flood may have been what it took to complete the circuit?

thanks for the pointers, will let you know how it turns out!

BF