Copper vs. Stainless Steel
One of the issues often struggled over by the beginning distiller is what material should their still should be made from. Stills are only safely made from one of two materials; copper or stainless steel. Both materials have their advantages.
Stainless steel has the advantage of being very strong and durable as well as being easy to clean (especially when of the polished variety). It is less expensive copper and because it is so much stronger it can be used in a thinner guage thereby resulting in a significantly lower cost overall. The problem with stainless is that it is a poor conductor of heat. This is not so much of a problem with direct heat applied to a boiler but presents problems in any column where you are looking for naturally generated reflux as the steam vapors rise through the column. Stainless also contributes nothing to the breakdown of esters and sulphuric compounds which is necessary to produce high quality spirits.
There are several manufacturers who build all stainless small scale distillers. They typically concentrate their efforts on forced reflux designs that produce high proof tasteless alcohol. This is the only way they can avoid most of the foul tastes resulting from the abscence of any chemical catalysis occuring in the still.
Copper is the traditional material used in commercial still construction and for good reason:
Copper catalyses the breakdown of esters and sulphuric compounds in the steam vapors. These volatile compounds are produced during the fermentation process and are highly undesirable in the distilled spirit.
Copper avoids the production of ethylcarbamat which is a toxic substance formed from cyanides. Again these are nasty chemicals you don't want in beverage spirits.
Copper improves the quality of the final product when the mash is not biologically perfect.
Copper improves the aroma of the final product.
Copper is a great conductor of heat. This allows for good natural reflux production in a still column as well as very efficient condensers.
Ideally then it would seem that copper would be the ideal material for the entire still and that may be true if economics were not a concern. The problem with copper is that it must be used in greater thickness to be strong enough and therefore costs are driven up beyond the budgets of most hobby distillers. We would not use a copper dome less than 16 ga or a copper pot less than 12 ga on distillers up to 15 gallon (60 quarts) useable capacity. Larger stills would require even thicker.
There are a couple manufacturers of small scale all copper distillers. One down in Arkansas builds literal artwork but his prices are very high and the guage of material is thinner than we would use on comparable sized stills. There is another in Indiana who build stills of material so thin we wonder how they can even get them shipped to the destination without damage. Material costs simply prevent a good option for an all copper hobby sized distiller.
We therefore have combined the use of the two materials to produce stills that are the best combination of functionality, durability and cost. Our stainless pots are durable, easy to clean and economical. Our designs use all copper domes and columns to maximise the contact with the steam vapors to achieve the full chemical reaction that copper offers. We think you will agree that our stills are the best available for the hobby distiller.