There is something we discovered and that we need to talk about. Over the last year, we have investigated the manufacture of copper stills next to our existing stainless steel iStill suite. Why? Simply because, when we look at the market, the majority of stills being sold is still made from copper.
I want to inform you that, based on recent research findings, we will not build copper stills. Is that what I feel we need to talk about on an industry level? No, I do not propose to discuss our decision. What I want instead, is to discuss why we decided to stop the copper project. The reason behind our decision affects us all and is therefor a topic that deserves a wider discussion.
Here is why we stopped developing copper stills: ethyl carbamate formation.
Ethyl carbamate formation
Ethyl carbamate is carcinogenic. It can cause cancer. Ethyl carbamate is formed during distillation, when the run is performed with a copper column or copper riser.
Fruits (like apples and apricots) and grains (like barley) contain cyanide. During fermentation the cyanide is released into the wash. During distillation a part of it travels up the column or riser.
When that column or riser is made from copper, the cyanide oxidizes with copper into cyanate. And when cyanate comes in contact with alcohol (in your still or in your bottle), it forms the toxic ethyl carbamate. These are the schematics:
cyanide + copper => cyanate + ethanol => ethyl carbamate
Glass and stainless steel columns and risers are chemically resistant. Research shows that glass and stainless steel do not transform cyanide into cyanate into ethyl carbamate. Like this:
cyanide + stainless steel / glass ≠ cyanate + ethanol ≠ ethyl carbamate
Since we now know that copper stills cause ethyl carbamate formation, a carcinogenic substance, shouldn’t something be done about it? Isn’t it in the industry’s interest to manage this, preferably to zero, or as close to zero as possible? Can craft distillers afford not to act, given their responsibility towards their customers, the consumers? And do you feel we need to play a role here?