Copper in stills, effect on sulphur compounds research

[SenileToo]

At the risk of furthering riot, I have an application question. Accepting that copper in the vapor path is a good thing I have a choice to make regarding column packing. I have an all copper 2" diameter reflux column still. The column is 45" tall in two sections: 15" bottom section, 30" top section. The head / reflux condenser section is also copper. Many sources say this is enough copper in the vapor path to handle any sulphur. I have the following packing options available:
1. Copper mesh
2. Stainless steel scrubbies (3M)
3. Small size Raschig rings

The depth of my indecisiveness has me on the verge of therapy...

Originally I was thinking 2/3 Raschig rings on the bottom and 1/3 copper mesh on the top. Then I was overwhelmed with the body of work by those swearing by SS scrubbies, followed by a crescendo of voices on behalf of all copper mesh.

I'm inclined to the SS scrubbies for ease of maintenance, but I dunno... by the way, the 3M scrubbies have an SS band in the middle holding them in shape. Does this get removed?

Anyway, is there a consensus that may help me make up my damn mind so I can get on with making some vodka?

I really appreciate and have greatly benefited from all the advice in this forum!

[der wo]

Sorry, we don't have a consensus here. Some member will tell you, they don't need any copper, other will tell you they prefer every part of the still being copper. Perhaps the most members never thought much about it and simply are happy with that amount of copper they have in their stills due to practical reasons (copper is easy to cut and solder for example), because they are happy with their spirits. And if they are not happy, there are other reasons which are responsible for it more likely.

It's part of your therapy, that you make your own decisions.

[still_stirrin]

I also want to add to der wo's response, that mixing packing media will upset the "stacking balance" for your column. Since the hot vapors rise through the descending (condensed) liquid which is saturating the packing, different materials, surface area, and heat transmission properties of the packing will affect how the rising vapors interact with the descending liquids. This will effect the stability of your reflux and expectedly, the purity as well.

So, try all three packing materials....but try them independently with each other. Satisfy yourself, but don't complicate your test (and possibly creating more "troubles than worth"). Asking about using multi-media packing is a question that comes along once in a while by a new member simply because they don't have enough experience; distilling or with their own (unique) equipment.
ss

[SenileToo]

I also want to add to der wo's response, that mixing packing media will upset the "stacking balance" for your column. Since the hot vapors rise through the descending (condensed) liquid which is saturating the packing, different materials, surface area, and heat transmission properties of the packing will affect how the rising vapors interact with the descending liquids. This will effect the stability of your reflux and expectedly, the purity as well.

So, try all three packing materials....but try them independently with each other. Satisfy yourself, but don't complicate your test (and possibly creating more "troubles than worth"). Asking about using multi-media packing is a question that comes along once in a while by a new member simply because they don't have enough experience; distilling or with their own (unique) equipment.
ss

Thanks very much for the advice. That's kind of what I thought regarding mixing media. It was a recommendation in some literature on the use of Raschig rings. I do think I'll try all Raschig rings first since I have them and they're easy to use. I have two stills of my own construction http://ww.homedistiller.org/forum/viewt ... 50&t=59830 I have made four reasonably successful runs of all-grain corn whiskey using my pot still and now want to try out my LM/VM combo column to make vodka.

[casper the Irish]

I have copper mesh at the bottom, SS mesh above.
Copper too near take off (that would include cooling coils, head and Lyne arm) are known to catalyse unwanted compounds.
Read the ethyl carbamate threads.

My experience is that about the first 6" of copper works hard at cleaning up sulphur compounds. My bottom two rolls of copper mesh (4" long) go black. Above that they stay bright enough. So any more than a foot does not seem to be doing anythhing much.

I would keep some copper in the bottom section, maybe with a centering collar to separate it.

I was in Makro looking at SS scrubbies, a dozen for £7. Some were proper SS looking unruly coils that easily tease apart, others were tidy with a band around, I swear they had sponge inside, but small print says they are not pure SS.

Why an LM/vm combo for vodka? LM is able to collect tails which you don't want, while VM is better at compressing hearts.
Look up Dad300 on CCVM. construction is beautifully simple. Or Manu de Hanoi on CCLM.

If you are thinking to multipurpose your next build it is worth reading Odins thread on adding feints to improve refluxed whiskey hearts. Feints have the flavours, and reward us with the hangover. It is possible to flavour pure VM hearts.

[der wo]

My experience is that about the first 6" of copper works hard at cleaning up sulphur compounds. My bottom two rolls of copper mesh (4" long) go black. Above that they stay bright enough. So any more than a foot does not seem to be doing anythhing much.

The work on the sulfur is no oxidation. So the oxidized copper is no proof, that the copper worked. Same clean copper is no proof that it doesn't works. When it works, copper and sulfur are connected to copper sulfate, which is blue and green. So if you see blue or green copper, it is most likely that it worked. But if you don't see it, it is no proof, that it didn't work, because copper sulfate is soluble and probably flushed to the boiler.

[MDH]

Not sure how to interpret der wo's post...

From the wiki on copper sulfide...

A black colloidal precipitate of CuS is formed when hydrogen sulfide, H2S, is bubbled through solutions of Cu(II) salts

That black precipitate cannot make it through distillation and is thus the desirable product of reaction between copper and sulfur.

Copper sulfate is not formed during distillation. Anything soluble and blue which ends up in your spirit is probably copper-ammonium complex or fatty acid interaction with corroded copper in the condenser.

[der wo]

My fault. Not my best post.

Yes, if we talk about H2S, you are right. Stinky H2S forms unstinky CuS (copper sulfide). And the black CuS is solid and insoluble, so it remains on the surface of the copper.
For example the treatment of wine with copper sulfate: Copper sulfate + stinky H2S -> Copper sulfide + unstinky H2SO4. I know you don't like this treatment. I have read all your posts about that.

But what's with all the other compounds? Here...
http://onlinelibrary.wiley.com/doi/10.1 ... 0450.x/pdf" onclick="window.open(this.href);return false;" rel="nofollow
...they write in Malt Whisky distillation about problems with dimethyl trisulfide (DMTS) and many other sulfuric compounds. But nothing about H2S. It's a practical study, they didn't study, which copper compound is formed, they only studied which volatile sulfuric compound is affected by the copper.
I was sad, that you didn't wrote in the thread about it, the "the answer was copper"-thread:
http://homedistiller.org/forum/viewtopi ... =1&t=63358
We quoted you there a few times.
If you have more information, for example about the reaction between DMTS and Cu in detail, I would be very happy to read it here or there.

Of course nothing blue or green ended in my spirit. But I had blue and green on copper parts in the boiler after a low wines spirit run. Definetely no copper sulfide or oxide. Perhaps copper sulfate.

[thecroweater]

Casper it would be far better if you didn't use misleading terms like "are known to" when there is an abosulute shit ton of conflicting study. One thing that is for sure known is if there is a copper column then it does not matter a damn what is in the Lynne arm or condenser. Statements contrary to this very simple logic are simply horse shit, that's not an opinion but basic logic and common sense ( which for some reason is not as common as one would expect)

[casper the Irish]

I thought Dad said to keep copper away from take off so that no condensing Ethanol is carried over that had touched copper (to catalyse ethyl carbamate precursors).

You don't need cooper to end up with this compound, you need urea and ethanol.

Copper sulphate is blue. Cuprous oxide green. Pale blue Hydrocyanic acid and other precursors to EC are formed from urea and hot Ethanol condensing on copper or platinum as a catalyst. Ethyl carbamate is a white soluble salt and can be seen at the base of reflux columns, sometimes Lyne arms and worms

[thecroweater]

Bzzt wrong but I can't be fagged going through it again (and again) . You can Google it your self here's the obvious place to start
https://en.m.wikipedia.org/wiki/Ethyl_carbamate" onclick="window.open(this.href);return false;" rel="nofollow
Facts don't change just because you fail to comprehend them.

[Fiddleford]

Considering what i read i feal the a stainless mash still and a copper spirit still would benefit maybe stainless onto a tall copper thumper going into a stainless condenser

[Jes2xu]

http://whiskyscience.blogspot.ca/2014/10/copper.html

too good of a link not to share...

Must admit as a newb this was one of the first "really, REALLLLLLYYYYYY" moments I have had.

Nice to see something with a little weight behind it on the topic. Appreciate shit like this!!

[Alchemist75]

I've tried using steel, glass and copper parts over time.
Only copper kicks that rotten egg bouquet that comes through after the stripping run. It's hard to tell what other affects it might be having because a rhinoceros's butthole is sufficient to overwhelm everything else in your drink. Maybe iron or some other reactive metal would work as well? I've read this article, liked it and would say that regardless of whatever else may make up the composition of your still the lyne arm, at a minimum (or column packing) needs to be of copper. Time tested material that unquestionably improves the flavor and aroma of young spirits.

[thecroweater]

no iron won't do shit except taste awful just copper or platinum copper bullion price is about $6.67 per kg and platinum is $30,665 p kg , copper is the cheaper option

[Alchemist75]

Oh man, I can only imagine an all platinum still. Sounds like something you'd be given after winning a contest. I'll stick to copper until otherwise notified.

[DetroitDIY]

Only copper kicks that rotten egg bouquet that comes through after the stripping run. It's hard to tell what other affects it might be having because a rhinoceros's butthole is sufficient to overwhelm everything else in your drink...

That's excellent! I haven't laughed at anything on this forum so hard as this comment. You're my kind of Alchemist.

[DetroitDIY]

On single malt whisky made in 1. a complete stainless steel systen; 2. a complete stainless steel suystem with copper catalyst with more surface area than a complete copper column.

The malted barley was fermented in an uncontrolled way. No temp control, no pH control, no yeast nutrients.

I found that the single malt made with the catalyst was smoother. The non-copper treated single malt was harsher, more funky.

That's very interesting Odin. I'm thinking your catalyst was something like the catalyzers shown in other threads with a copper corrugation wound up for a low pressure drop section (http://homedistiller.org/forum/viewtopi ... 17&t=31805" onclick="window.open(this.href);return false;" rel="nofollow). I also read/interpreted somewhere in the "copper in the descending path" thread the theory that as the urea and ethanol (especially hot ethanol) react in the presence of copper to form ethyl carbomate, three is less of one of the reactants to produce EC over time. In fact there was a lot of attention paid to the exponentially increasing trend of the EC formation post distillation that humbledore shared in the same thread (http://homedistiller.org/forum/viewtopi ... 7&start=60" onclick="window.open(this.href);return false;" rel="nofollow), but I noticed that that increasing rate was a transient condition and that somewhere in the 8-24 day range (for that study) the rate of change began decreasing. This made me think that given some time, the EC creation would drop to zero... perhaps because all of the urea or copper in the distillate was used up.

Where I'm going with all this is... If the urea is being consumed in the reaction, I wondered if during distillation, the vapor were exposed to a sufficient amount of copper (such as you may have done in your experiment), that the urea may be entirely reacted with the copper, and that none might be available to form EC as it ages even if some copper is present in the barrel.

Where was the large surface area of copper in your stainless set up?

If this hypothesis is correct, I wonder if a large surface area of copper above the dephleg could prevent EM from forming in the product, regardless of whether a copper or stainless condenser were used. Or perhaps some urea transfers into he product side no matter what and the problem persists... Or perhaps I need to not think about it too hard...

[thecroweater]

you got it, much was made of the descending path and vigorous efforts were made to ignore the ascending path (where it actually mattered) . The truth of the matter is sufficient copper in the ascending path will clean up a bunch of unwanted compounds including sulphur and EC but copper is not needed to for it. Ethyl carbomate (urethane) is a compound of urea and ethanol and can (will) form during ferment, heat can exacerbate this along with other catalysts which copper is claimed is one. Now if it is as good a catalyst as claimed a copper column is holding to insure this is not a problem in the final produce just as it does with sulphur.

[aircarbonarc]

This is from an engineer who was previously employed at the Jamisons distillery. The surface of copper isnt as smooth as Stainless or glass so it actually micro distills by catching vapours in its rough surface and catches sulphurous compounds.

It sounds like a basic simple answer so I might go with it, even the big distillers use copper, I guess they've maybe done the reaseaech for us. I'll get some of sources of information to get on this forum to open our minds.

[WhiteL[ghtning88]

After reading this thread and also the paper "The Impact of Copper in Different parts of Malt Whisky Pot Stills" it seems that it would be helpful to add some copper rings into the boiler of my stainless steel still. Has anybody tried this? I'm thinking of cutting a bunch of1/2" copper tube into 1/2" long rings and throw them into the bottom of the boiler, yay or nay?

[SaltyStaves]

After reading this thread and also the paper "The Impact of Copper in Different parts of Malt Whisky Pot Stills" it seems that it would be helpful to add some copper rings into the boiler of my stainless steel still. Has anybody tried this? I'm thinking of cutting a bunch of1/2" copper tube into 1/2" long rings and throw them into the bottom of the boiler, yay or nay?

Copper speaker wire threaded through the rings allows it to form and hold any shape (important when keeping it clear of an internal element). Very easy to fish out and hang to dry too.

[WhiteL[ghtning88]

That's a good idea, I was just going to toss them in the bottom and let them dance around. I'm not sure that hitting the element would be a problem, but it would be easier to get them back out. Thanks!

[Saltbush Bill]

Has anybody tried this?

A lot of people here, including myself run copper in their boilers its common practice.

add some copper rings into the boiler of my stainless steel still.

Adding some copper to the still its self would be of a lot of benefit to, if you haven't already done so.

[WhiteL[ghtning88]

I'm adding a copper column and an onion as we speak, thanks for chiming in. I can't wait to cut up some tube and try it.

[LWTCS]

Has anybody tried this?

Really?

[WhiteL[ghtning88]

LWTCS, I'm new at this, I'm just trying to get some knowledge.

[WhiteL[ghtning88]

Do you think there is any difference between soft copper or rigid copper, as far as effectiveness?

[Tennessee_Spirits]

Copper reacts with sulfates and other sulfur containing ions in the vapor and forms copper sulfate (CuSO4) which is blue and sparingly soluble in water. It is a pretty blue and trace amounts can impart this color.

Copper is an essential trace element and I doubt the amounts we get distilling are very toxic. Copper sulfate is used as an algaecide at about 1.5 PPM.

[JC973]

I work in an industry that uses a lot of plated pieces, could we plate the SS tri clamp fittings with copper?