The condenser coil should never be made of copper. Copper is needed to clean vapors from sulfur and sulfur compounds only when they move upward. Then all the copper salts remain in the cube. As the vapor moves downwards (the condenser coil), the alcohol reacts with copper and verdigris (copper acetate - copper salt of acetic acid) is selected, what is not good for the stomach. Condenser coils should be made of stainless steel, AISI 304-1.4301-S30400, AISI 321-1.4541-S32100.
Otherwise, the final product will have a “hardware smell”