Larger capacity stills make “ordinario” after the first distillation. Then smaller capacity stills do the second distillation to get tequila.
The inspiration for the copper still is coming from Scotch still design.
Copper stills are very expensive
They filter out sulphur naturally and it provides a clean and soft finish.
The still strength is a little bit over 110 proof (55% abv).
The water used to dilute the tequila from still strength to bottling strength (typically 40% abv) is rain water or spring water – it is identical to the water ued for production and then the batches are blended.