With two single grain whiskies on the market just now – Borders & The Tweeddale A Silent Character – we’re often asked; ‘What is grain whisky?’
Let’s start with what it’s not by comparing it to the well-known single malt:
Single: one distillery.
The ‘single’ refers to the number of distilleries the whisky in the bottle is from.
Single cask means the whisky comes from just one cask but single malt simply means that the whisky is made at one distillery but is generally a vatting of multiple casks – unless stated otherwise – combined after maturation for bottling.
Malt: this refers to the ingredients of the whisky. Single malt Scotch whisky must contain only malted barley. That’s it. Peated or unpeated, it must be 100% malted barley.
Single: one distillery. Again – the ‘single’ here simply means the contents of your bottle is distilled at one distillery, even though it comes from multiple casks.
Grain: While malt whisky must be 100% malted barley, grain whisky can be made from any cereal grain such as wheat or corn. In Scotland this includes small amounts of malted barley in combination with another grain.
In the case of our Borders Highland single grain whisky we combine 50% malted barley and 50% wheat.
The Tweeddale A Silent Character is our 27 year old independent bottling from the now silent Cambus Distillery. Cambus was often found in Richard Day’s cellar book and used in many original Tweeddale blends.
Conventionally, it’s said that grain whisky has lighter flavour components, often with sweeter notes as well, and is generally Bourbon casks matured.
It’s rare for a grain whisky to be so high in malt content by nature. In fact Borders is the only Scotch that we know of with this half and half ratio.
Barley is such a flavoursome grain, that when used in such a high quantity, it gives our Borders grain more body. By doing so we introduce more complexity into the whisky, which is enhanced by our use of Oloroso sherry cask finish and maturation as well.
Single Grain Production
There’s also a difference in the process of distilling grain whisky compared to malt whisky. Single malts are produced on the traditional copper pot stills in batch (smaller) processes.
Today’s grain whisky however is – most often – distilled in a different kind of still known as a column or Coffey still (no you don’t get hints of café noir, it’s named after its creator Aeneas Coffey, who used to be an excise man, and arguably revolutionised modern spirits production).
We could write a whole book about Coffey Distillation, but here’s a nutshell explanation according to our own Chris Hoban:
You have two columns filled with copper plates. At different points throughout the columns, the liquid is heated and cooled. This causes a continuous distillation spirit flow. If you’ve ever studied an oil refinery it works something like this, although you are getting 94% abv grain spirit at the end of the process (as opposed to around 72% for malt whisky on a pot still). It still has flavour, but it is cleaner and softer than malt. A grain distillery can produce 10 bottles per second, which is significantly more than pot still distillation.
Now that you understand what grain whisky is, why not try it for yourself!