F – like cask storage
How are whisky casks stored?
Whisky casks are usually stored horizontally. This is the traditional way of cask storage.
How are the barrels stored at St Kilian?
At St. Kilian, the whisky matures horizontally, with the casks lying on galvanised steel racks. The opening of the cask, the bunghole, points upwards. Each rack can hold two casks and can be stacked relatively easily. Four to a maximum of five such racks can be stacked on top of each other. For this to work well, the cask sizes per rack must match in pairs. Such metal racks are widely used in the beer and wine industry.
How many racks are stacked on top of each other at St Kilian?
In the warehouses of our Bunker City in the Odenwald, up to three such metal racks fitted with casks are stored on top of each other. This storage is very similar to a traditional Scottish warehouse, the so-called Dunnage Warehouse.
What is a racked warehouse?
A racked warehouse is a modern warehouse that is much larger than a Dunnage Warehouse and is designed for larger quantities of casks stored horizontally. The temperature in such a warehouse fluctuates more seasonally than in a Dunnage warehouse, and there can be greater temperature fluctuations between the upper and lower shelves within the racked warehouse.
Are casks always stored horizontally?
No. Whisky casks can also be stored upright. This is the case in a so-called pallet warehouse. This makes better use of the available space by packing the casks closer together on wooden pallets and stacking them on top of each other. This type of cask storage is often practised in Ireland, where six casks are placed on a pallet and these are stacked on top of each other up to seven pallets.
What are the advantages of horizontal storage on steel racks?
This type of storage, with the bunghole facing upwards, makes it easy to take a sample of the matured whisky from the cask. This means that the degree of maturity of a whisky can be checked at any time without having to move the cask in the warehouse, which is more or less time-consuming. Secondly, the casks can be easily moved on the metal racks using a forklift truck, which simplifies handling enormously. Even entire cask blocks can be moved in this way.
Does the position of the bunghole have to be taken into account for horizontal cask storage?
Not in principle. In the large racked warehouses in Scotland or the USA, the casks are moved in and out of the storage racks by rollers without paying attention to the position of the bunghole. It is therefore necessary that the bunghole of the cask is well sealed with a wooden plug (wooden bung) and a bung cloth. At St Kilian, the bunghole of the cask is always at the top of the steel rack. This is also sealed with a food-safe silicone stopper that can be easily removed from the cask in the rack, allowing convenient access for sampling.
What must be observed when storing upright on pallets?
An important point when storing whisky casks upright is the risk of leaks. When the casks are upside down, quite a bit of pressure is put on the bottom of the cask, which is not in the direction the casks were designed to withstand the force. The result is often a more or less curved cask lid, which can lead to leaks. When casks are stored horizontally, this pressure is guided downwards sideways over the cask lids without deforming them.
Why did St Kilian choose the metal racks?
The many advantages offered by this type of cask storage have led us to implement metal racks in our warehouses. These galvanised steel racks are ideal for transporting and handling the casks, which have to be filled at our distillery in Rüdenau and transported to our warehouses in Bunker City, and have proven their worth so far. In addition, this type of storage on steel racks ensures good air circulation, as the casks have sufficient space between them, which ultimately also benefits optimal maturation.
Do all the casks at St Kilian mature horizontally?
No. We also store a small number of casks upright, four per pallet. This applies exclusively to bourbon barrels in order to save some space for this type of cask. We also see this as an experiment to see how this upright storage affects the maturation of our whisky in bourbon barrels.
