How Many Bottles Are There In A Whisky Cask?

What is a whisky cask?

First, let's start with the basics: what is a whisky cask? A whisky cask is a wooden barrel that holds whisky as it ages. In Scotland, casks are made of oak, and whisky must age in the barrel for at least three years. While the whisky is in the oak cask, it interacts with the wood. This process improves the flavour of the whisky, and gives it its characteristic colour.

How big is a whisky barrel?

Before we answer how many bottles of whisky can be held in a cask, we need to talk about barrel sizes. There are lots of different types and sizes of whisky cask. That means the number of bottles each kind can hold will vary. You can read about all the different types of whisky casks here. But in this article, let's look at three common types:

• American standard barrel. Also known as a bourbon barrel. These hold between 190 to 220 litres of whisky.
• Hogshead. These are around 20% to 25% larger than an American standard barrel. They can hold between 225 to 250 litres of whisky.
• Butt. Sherry Butts are a common example. Butts are twice as large as a hogshead. These can hold between 475 to 500 litres of whisky.

How many bottles are there in a whisky cask?

The most common size of whisky bottle is 700ml. This is certainly true for the UK, Europe and Asia. A notable exception to the norm is in the US, where bottles are 750ml. If we assume a bottle size of 700ml at natural cask strength, then the three most common types of cask can hold the following number of bottles:

So, there is an average of 440 bottles in a typical whisky cask.

Factoring in the Angels' Share

Each year the whisky ages in a cask, a small amount will evaporate. This is known as the "Angels' Share". Typically, 2% to 4% of the whisky will evaporate each year. During the first couple of years, it will be towards the higher end of that rate. And then the rate will gradually slow towards the lower end of the range throughout the cask’s life.

Why is the Angels' Share relevant when we're calculating the number of whisky bottles in a cask? Well, the annual evaporation means that an older cask will have less whisky in it than a younger cask. And clearly, less whisky means fewer bottles. So while the figures in the above table are true for a cask at maximum capacity, the figure will drop over time. 

If you own a cask the best way to get an accurate view on how much whisky is in your cask, and therefore the number of bottles, is to ask for a re-gauge report. The warehouse will check your cask to calculate exactly how much liquid is in it, on the date of the re-gauge report. From this accurate figure, you can then calculate the bottle count. For an approximate view, find out how much whisky was in the cask when it was filled, then deduct 3% for each year of its age.

Learn more about whisky casks

If you'd like to learn more about whisky casks then Spiritfilled is here to help. We're an expert cask broker. We buy and sell the best whisky casks every day. And, we bottle our own whiskies. So whether you're looking to buy, store, or bottle a cask, we're here to help. 

You can download our free Whisky Cask Investment Guide here. And you can contact us here, we'd be pleased to talk.