Copper annealing: what is it, why is it done and why isn't it the same as using an alembic?

COPPER ANNEALING: WHAT IS IT, WHY IS IT DONE AND WHY DOESN'T IT HAPPEN IN ALEMBIC USE?

Copper is king when it comes to handcrafted alembic stills. But for each piece to work as it should - durably, safely and effectively - the metal needs to go through several stages. One of the most important (and least known) is annealing..

WHAT IS ANNEALING?

Annealing is a thermal process in which copper is heated to a controlled temperature and then cooled slowly. The aim? To temporarily alter its physical properties to make it more malleable, flexible and easier to work with.

During annealing, the metal's internal grains reorganize, reducing stresses built up in processes such as bending, hammering or welding. The result is “relaxed” copper, which is easier to shape precisely and less prone to cracking.

Why is it necessary to anneal copper?

During the manufacture of the alembic, the copper is bent, shaped, hammered and soldered. With this work, the metal becomes hard, tense and less flexible. If we continue to work without annealing, it can:

• Cracking on bends or folds
• Difficulty maintaining precise formats
• Losing quality in the finish

By annealing, we give the copper back the plasticity it needs to continue working with precision, safety and high quality.

How about cleaning it? Does it need to be heated?

Yes - we often anneal the copper before cleaning. The heat helps to loosen dirt, oxides and residues, making it easier to polish and finish. It's a way of respecting the material, making it ready for its final use and valuing the craftsmanship.

Is using the alembic to distil on fire annealing ?

No. They are totally different processes.

When the client puts the alembic on the fire to distil:

• The temperature is much lower than in annealing.
• The aim is to produce steam, not to transform the metal.
• The copper is already prepared and ready for use - it just has to fulfill its function.
• The part of the alembic where the flame falls is reinforced in relation to the other parts.

It's like comparing a pottery kiln with a kettle: both use heat, but for completely different purposes. The pottery kiln is used to fire and harden the ceramic, transforming the material permanently - just as annealing temporarily transforms the properties of copper. Afterwards, the kettle only serves to heat the water. The heat doesn't change the kettle, it just heats the liquid inside.

Knowing this reveals the care and technical knowledge behind each piece. A well-made alembic is not just beautiful. It has been through:

• Precision thermal processes
• Informed artisanal decisions
• Respect for material behavior

Each flame has a different role:
In manufacture, heat transforms.
In use, heat activates.

CONCLUSION

At COPPERCRAFTS, copper isn't just shaped - it's respected. Annealing is an invisible but essential step. It's what ensures that each still lasts, works safely and has the finish that master distillers deserve.

❗ Important: This blog makes it clear that annealing is a technical process internal to production, unrelated to the subsequent domestic or industrial use of copper, such as putting an alembic on the fire.