I have just come back from a trip to the Pierre Guérin factory in Niort, France, where Rathfinny’s tanks are currently being fabricated. I met up with Gerard, our winery engineering consultant, to inspect and make sure that the tanks are built exactly to our specifications. It is amazing to see the different techniques and tools used to assemble cylindrical tanks from flat stainless steel sheets.
Sheets are first welded together, then cut to desired dimensions to become one tank. Welds are then completely polished, to the point where they become difficult to detect. You can see on the pictures before polishing.

After polishing, they are then curved to size and welded along the seam to form a cylindrical shape, at this stage there is no top or bottom. Those are different pieces built separately, welded onto the cylindrical body form.
Tank tops and bottoms start as circles, from which a slice is taken out so that they can then be bent into a cone. Those cones are finally welded—yes, that is a lot of welding—to each end of the cylindrical tank.

Wine tanks must be outfitted with various items:
- an access door, to access inside the tank,
- valves, to connect hoses to transfer juice or wine,
- temperature probes, linked to a temperature control system.
Openings are cut through the stainless steel, either mechanically or by a plasma ray.
You can see above some the pre-cut of where the door will be assembled.
Jackets, through which a liquid coolant will run to regulate the temperature of the wine, are welded in a spiral shape, either manually for smaller tanks, or with a machine for larger tanks.
Legs are then attached to the bottom of the tank for stability.

The inside and outside tank surfaces will be polished, producing a mirror finish on the inside, making it so smooth that virtually nothing will stick to it! It may sound inconsequential, but this makes cleaning the tank an easier task than it otherwise could be. It enhances hygiene, which is a critical point in winemaking since contamination of the wine can lead to spoilage.

Lastly, external components are fitted, including the valves, level gauge, door mechanism and chimney.
Here, Gerard inspects the first completely finished Rathfinny tank. He approved, and so did I!

We are expecting the delivery, installation and commissioning of our order of 24 tanks the first week of July, along with our Coquard press.
And we’ll be ready before harvest—well, that’s the goal at least!