Whiskey is a truly gorgeous spirit. We could write odes to the aroma and the flavour, but another important draw of whiskey is its beautiful colour. While the many shades of whiskey vary, most whiskey has a brownish hue. So what gives whiskey its deep tint? The answer also plays into what grants whiskey its mature taste: charred oak.

Whiskey is cask-aged, often in charred oak barrels. In simple terms, charring a barrel means lighting the inside of it on fire so that the wood produces char. Here’s a video of Jameson doing it.

There are different levels of char, which (among many other factors) help contribute to whiskey’s flavour. Whiskey that’s been sitting in charred oak for years often has a deeper colour (and many would argue a more complex flavour) than whiskey that’s only been hanging out for a few months. However, many new distilleries have used several methods to “speed up” the aging process, including sticking charred oak staves into batches of whiskey or using smaller barrels so that the surface area to volume ration is increased. Other times, companies will add artificial colouring to make their whisky look darker. Brown rum goes through the same processes.