Copper in stills, effect on sulphur compounds research

[stilldistillin]

http://whiskyscience.blogspot.ca/2014/10/copper.html" onclick="window.open(this.href);return false;" rel="nofollow

too good of a link not to share...

[bearriver]

That piece has a long list of sources ranging from 1830's until today. Interesting stuff.

[emptyglass]

Damn stilldistilling, the stainless still makers guild will be hunting you down...

You know they have been working hard to discredit copper and the role it plays in stills for a long time now. They dont want guys to believe that copper is a superior material to use for making a still.

Good on you for dusting this old link off and posting it. It has been posted before, but a long time ago.

The guild has been working hard to tell everyone "copper is bad", I guess they have to work hard as the evidence is there that copper does a better job of making your product taste better. If it didn't, all those copper stills in the picture in the link would be shiny sterile stainless. If it was toxic, wouldn't they be shiny sterile stainless. If it did nothing to remove sulphides and other unwanted flavours produced in the fermenting process, they'd be shiny sterile stainless.

But they are not, they are copper. If stainless was so good, wouldn't guys with that much cash make stainless stills?

I rest my case your honour.

[pfshine]

Now SS does have a spot in distilling if you ask me. It's cheap and non toxic. That being said none of my stills will ever be absent of copper due to its amazing ability's and beauty.

[emptyglass]

You are right Pfshine, Stainless does have a place.

I feel a kind of need to bat for copper, as it seems stainless is being pushed as a material that can do everything that copper can. I like to be unbiased, but it seems the guys selling stainless stills wish stainless to be seen as every bit as good as copper, and this is not the case.

Stainless steel is a fantasic material if used in the proper ways, and in the right places.

But as a material that handles the vapour, its second rate.

I understand the attraction to using stainless for columns, its cheap, its easy to work, its available, but nothing good comes cheap.
Copper poses some challenges when constructing a column. Its expensive, its harder to get, and it has what seems to be "mysterious" properties. Its also a material that some are uncomfortable working with at first.
Truth; Copper is easy to fabricate, the tools are simpler, and its not as exotic as some may assume.

And its "mysterious" properties are also the properties that make it better to use where vapour is in contact with it, especially with whiskey.

It these properties were insignificant, all stainless columns would be pure stainless. The fact that nearly all of the stainless columns made include copper in some way shape or form is akin to an admission it is really the material a column should be constructed from.

And if you consider what you can save by making good product, the extra $$ spent on making a still from copper pay back very quickly.

[MDH]

There is no reason you cannot have an entirely stainless steel still with a section of copper sponge with the vapor path ensuring almost 100% complete contact with copper at some point. In commercial stills this is called a catalyzer and it sits at the top of the column as the lack of water prevents any chemical reactions from undoing themselves.

[Bobdoe]

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

too good of a link not to share...

Why are the stills shown in the photo on that link different colors? They are all copper stills, but some are dull reddish but others are more typical copper color.
Bd

[still_stirrin]

Why are the stills shown in the photo on that link different colors? They are all copper stills, but some are dull reddish but others are more typical copper color.
Bd

Age of patina (depth), maybe?
Lighting when the photo was taken, maybe?
ss

[pfshine]

Alot of things cause this. Heat applied, oxygen content of the copper different impurities amount of use airflow around it and cleaning.

[stilldistillin]

Has anyone tried a controlled experiment where the same ferment was used in two similar stills, one from copper and one from SS, distilled at the same time and place by the same operator? What were the "taste results" ? That's what really matters.

I thought SS was more expensive than copper, no?

Personally I find SS too sterile. Copper is a nod to all the shiners that paved this road for us. It's worked for hundreds of years, why stop now?

Also, working with stainless is a royal PITA. Copper is easy to work with simple tools.

[pfshine]

In larger sizes of pipe SS is way cheaper, as well as sheet metal. SS is harder to work if you don't have to he knowledge or tools to work it.

[SaltyStaves]

Has anyone tried a controlled experiment where the same ferment was used in two similar stills, one from copper and one from SS, distilled at the same time and place by the same operator? What were the "taste results" ? That's what really matters.

Do a google search for The Impact of Copper in Different Parts of Malt Whisky Pot Stills on New Make Spirit Composition and Aroma.

[thecroweater]

right well "new make" is low wines just to get that straight right off the bat this time round

[MDH]

Has anyone tried a controlled experiment where the same ferment was used in two similar stills, one from copper and one from SS, distilled at the same time and place by the same operator? What were the "taste results" ? That's what really matters.

I thought SS was more expensive than copper, no?

Personally I find SS too sterile. Copper is a nod to all the shiners that paved this road for us. It's worked for hundreds of years, why stop now?

Also, working with stainless is a royal PITA. Copper is easy to work with simple tools.

Soluble copper compounds and some oxides react with sulfur. Copper is a catalyst and so are its metal oxides.

[SaltyStaves]

right well "new make" is low wines just to get that straight right off the bat this time round

I'm not sure where you get that definition, but I do not agree. 'New make' in the whisky world has always referred to cask strength spirit that is ready for aging.

[still_stirrin]

...I'm not sure where you get that definition, but I do not agree. 'New make' in the whisky world has always referred to cask strength spirit that is ready for aging.

Well...not exactly. According to this link, it is the liquor off still, ready to be tempered to cask strength. So, if you're splitting hairs...you're wrong too.
http://www.whiskymag.com/glossary/new-make_spirit.html" onclick="window.open(this.href);return false;" rel="nofollow
ss

[SaltyStaves]

So, if you're splitting hairs...you're wrong too.

Indeed. But I'm not a long way off.
Besides, the research paper I referred to uses both wash and spirit stills and results are taken from the spirit run. Even if thecroweater were correct with his definition, he'd only be pointing out an error in the paper's title.

[Hound Dog]

Wow! Guys are pretty passionate about what stills are built with. I see it being thrown out there about sellers of stainless supporting them but I see a lot of guys support stainless who don't build stills for others. Any strong copper supporters/stainless bashers on here happen to build for profit out of copper? I like DAD300's 50/50 way myself so I can get the benefits of copper in my boiler and column while having the sterile stainless condenser. Still working on my full stainless LM head though.

Ha! To each his own.

[thecroweater]

...I'm not sure where you get that definition, but I do not agree. 'New make' in the whisky world has always referred to cask strength spirit that is ready for aging.

Well...not exactly. According to this link, it is the liquor off still, ready to be tempered to cask strength. So, if you're splitting hairs...you're wrong too.
http://www.whiskymag.com/glossary/new-make_spirit.html" onclick="window.open(this.href);return false;" rel="nofollow
ss

hmm seems I was wrong guess that's happened before

[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).

For that reason my 3" column is 30" of copper tube stuffed with rolled copper mesh, topped by all SS all the way home ...30" ss column, Tee,and CSST RC and Liebig

[thecroweater]

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).

For that reason my 3" column is 30" of copper tube stuffed with rolled copper mesh, topped by all SS all the way home ...30" ss column, Tee,and CSST RC and Liebig

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

[Kareltje]

Has anyone tried a controlled experiment where the same ferment was used in two similar stills, one from copper and one from SS, distilled at the same time and place by the same operator? What were the "taste results" ? That's what really matters.

I thought SS was more expensive than copper, no?

Personally I find SS too sterile. Copper is a nod to all the shiners that paved this road for us. It's worked for hundreds of years, why stop now?

Also, working with stainless is a royal PITA. Copper is easy to work with simple tools.

Yes.
http://homedistiller.org/forum/viewtopi ... =1&t=62422
and therein the last one:

Another one, thanks to zedzedtop:

http://onlinelibrary.wiley.com/doi/10.1 ... 0450.x/pdf" onclick="window.open(this.href);return false;" rel="nofollow
Harrison, Barry et al.
The impact of copper in different parts of malt whisky pot stills on new make spirit composition and aroma.
Journal of the Institue of Brewing, 117 (1): 106-112, 2011

Most of the question we ask ourselves, are asked by professional distillers and professional scientist too.

I wonder if there is any research on iron and zinc. I have no bad experience with iron myself, other than the rust and the corrosion in contact with copper. Anybody seen any research?

My first still was iron with a copper condenser and I had no problems.
My current still is copper with a ss condenser and I have no problems.
When I use my copper condenser of my copper still I get blue or blueish low wines.
But I have no gaschromatograph to do research.

[bentstick]

"When I use my copper condenser of my copper still I get blue or blueish low wines." Why? I have been running all copper stills for 6 yr and only see it on Cleaning runs after build, never after they have been used.

[pfshine]

I have no bad experience with iron myself, other than the rust and the corrosion in contact with copper.

My first still was iron with a copper condenser and I had no problems.

That has to be the shortest most contradictory amalgamation of words I have ever seen.

[der wo]

Perhaps a link to Bagassos thread could be helpful here:
http://homedistiller.org/forum/viewtopi ... =1&t=63358
Treating wash or low wines with copper.

[Kareltje]

I have no bad experience with iron myself, other than the rust and the corrosion in contact with copper.

My first still was iron with a copper condenser and I had no problems.

That has to be the shortest most contradictory amalgamation of words I have ever seen.

I see!
The condenser is at the end of the vapour path, so the moving vapour had no adverse effect on the iron. The riser had a wall of 2 mm thick.
Problem has been, in hindsight, that I used bronze or copper boiling stones in a iron kettle. I had done better by using iron or zinc boiling stones.
And the design was not optimal: only a small opening, so the kettle was very difficult to dry and clean.

[Kareltje]

"When I use my copper condenser of my copper still I get blue or blueish low wines." Why? I have been running all copper stills for 6 yr and only see it on Cleaning runs after build, never after they have been used.

I do not know why. I asked in a thread http://homedistiller.org/forum/viewtopi ... 0#p7432295 and got an answer from cranky, saying that it is normal.
I was surprised because a iron still and copper condenser never gave blue distillate and from my copper boiler and ss condenser I until now did not get a blue distillate.

Today I washed my copper still and copper condenser and tomorrow I will use the combination again. I will report.

[thecroweater]

Using an Iron still is as ghetto as it gets. I've seen a stack of them in my youth, the grappa from some of them looked pre-aged and was not good for the body or soul. I am surprised Odin has not weighed in with his past iron woes. I kind of wish these MYTHS of the deadly copper stills were posted in the liars bench where they truly belong. If you have blue distillate you are most defginately doing something wrong, you need to put that puppy in park and have a good look at you methods and see what is different to what everyone else is doing. What I have been reading in the last several posts is very far from academic research or even valid hands on experience of the intended topic

[Kareltje]

I promised to report.
A wash of 7 litres of 5 %ABV, an old birdwatcher.
Two stripping runs in a 10 l copper boiler: one with a copper condenser, the other with a ss condenser. From 40 %ABV downward the copper condenser gave a very slight blue colour, especially when compared with the completely clear result of the ss condenser.
But I can not test on sulphur compounds.

[Odin]

Has anyone tried a controlled experiment where the same ferment was used in two similar stills, one from copper and one from SS, distilled at the same time and place by the same operator? What were the "taste results" ? That's what really matters.

I thought SS was more expensive than copper, no?

Personally I find SS too sterile. Copper is a nod to all the shiners that paved this road for us. It's worked for hundreds of years, why stop now?

Also, working with stainless is a royal PITA. Copper is easy to work with simple tools.

I have. 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. Over time the difference became less and less and after two years the one that didn't see copper felt a bit more interesting, multi-dimensional. What it teaches me is that copper plays a role, but it may very much depend on the amount of sulphur and/or the drink you make.

Regards, Odin.