Let’s paint a picture: you’ve just poured yourself a dram of a new whisky.

You then decide to go online to read more about the liquid story you’re about to enjoy.  You check out a few reviews (Hopefully one of ours as well, hint hint.)  And, as your reading, or watching, terms like “second fill”, “finishing” or “port pipe” make their way into your whisky receptors.  This post will not only help bring those definitions to light, it’ll also make you into a walking whiskypediac the next time you’re sharing a dram with friends or co-workers.

Let’s start with First Fill:

American straight whiskies are aged in new, or virgin barrels.  Easy peasy so far.  Barrels get reused.  So when you see “first fill” on a label, you’re looking at a bottle of scotch that was aged in that new barrel that was first used.  Wait, what?  Shouldn’t that be a second fill?  No.  First fill refers to “first” time scotch (or scotch-to-be) gets filled in that once original barrel.  Of course, each time a barrel is reused, the influence of the oak on the whisky spirit lessens.


This refers to the verb, not the number, if there is one, on the bottle.  Age is what we and whisky both do – get older.


This is about the changes, or development the whisky undergoes while in the barrel.  Whisky matures.  Some people aren’t sure if I do.


After sitting in a barrel for a few years, many whiskies go spend a few months in a different barrel (e.g.: wine, sherry).  This is done to add more complexity and flavour to the whisky.  Yum.

Single Barrel:

This doesn’t refer to ia cask’s marital status.  Many whiskies get vatted or mixed together before bottling.  When you see “Single Barrel”, it means that your whisky came from literally one barrel.

Cask Strength:

Whisky has to be bottled at a minimum of 40% alcohol by volume.  And, most whiskies get watered down before being finally bottled.  When your whisky is labelled as “cask strength”, nary a drop of water has been added so you’ll be receiving a hefty booyah abv of anywhere between 50% and 75%

Barrel Sizes:

The prefixes for the metric system, while simple because they denote the amount, length or volume (mega, kilo, deci, etc.), they’re kinda “meh” sounding.  Remember the names of some of these casks and you will be considered a whisky Einstein.

  • Blood-Tub(30 to 40 litres)
  • Firkin(40 litres)
  • Quarter Cask(125 litres)
  • ASB (190 to 200 litres)
  • Hogshead(225 to 250 litres)
  • Barrique (250 to 300 litres)
  • Puncheon(450 to 500 litres)
  • Butt (475 to 500 litres)

(I believe Sir Mix-A-Lot was musically opining about barrels when he rapped: “I like big butts and I cannot lie.”)

  • Port Pipe(550 to 650 litres)
  • Madeira Drum(600 to 650 litres)
  • Gorda(700 litres)

Remember the names of some of these casks and you will be considered a whisky Einstein. For example: Four Quarter casks equal one butt. Two Hogsheads equal one Puncheon. Seventeen and a half Firkins equal one Gorda.

Yes, a lot of stuff goes into the art and science of crafting of whisky.  Which then leads to a lot of whisky going into barrels. How much? Here’s a dram-sized factoid you can drop to up your whisky cred:  There are more 4 times more barrels of scotch-to-be than actual Scots in Scotland.

Put that in your Port Pipe and smoke it.  Cheers.