Tom’s “Officially Unofficial” Bruichladdich Blog
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The Basics of Distillation; Part 3
You’ll probably hear some unfamiliar terms in discussing the actual process of distillation. These terms appear in distilling brandy and whisky; I don’t know about white spirits like Vodka and Gin. One term is: Low wines. What does wine have to do with whisky? My theory is that this term probably came from some of the first applications of [double] distillation: Making brandy, which is distilled wine. So what’s low about it? Well, I suspect that the “low” comes from the fact that the ABV isn’t high enough yet, meaning the low wines have to be further distilled.
What about these: Foreshots? Heads? Middle cut? Feints? Tails? A “cut” is when the output of a pot still changes from undesirable to desirable (or vice versa). When the cut is made, the liquid output from the still is literally redirected to a different receiver (container). “Heads” (also known as “foreshots”) precede the “middle cut,” which precedes the “tails” (also known as “feints”). The “heads” or “foreshots” can contain unsafe or unpalatable chemicals. The “middle cut” is the desired output of the pot still. The “tails” or “feints” are what comes out of the still after sufficient alcohol has been extracted from the still such that the concentration in the output is no longer high enough.
We already know that the distillation process for Scotch takes at least two passes. The first pass is performed by the wash still, which takes the beery contents of the washback and concentrates the alcohol content to create the “low wines,” the output of the first step of distillation. The low wines are the middle cut of the wash still. According to this description, the foreshots off the wash still are discarded into animal feed. I have heard that a stillman (the person who operates the still; sorry for the politically incorrect term!) can tell by smell when the “middle cut” begins. The resulting low wines are 15-20% ABV, about double the alcohol concentration of the wash. Here are two additional descriptions of the distillation process, with decent diagrams.
It’s useful to step back and remember what’s happening here. The big picture is that distillation is a process of taking a liquid mixture that contains lots of chemicals with different boiling points, boiling the lot of them, and controlling the condensation process. The more volatile liquids will boil sooner than the less volatile liquids, so they can be preferentially captured since they will condense sooner. The pot still is not a continuous process. It is filled (the official term is: charged), and heated until virtually empty, then charged again for the next batch. (There are other types of stills that operate continuously, but they are not used in the production of Single-Malt Scotch Whisky. You’ll find them in petroleum distillation, Single-Grain Scotch Whisky distillation, and many other chemical engineering applications.)
The second step in the distillation process is another pot still known as the spirit still. The spirit still’s foreshots may be recycled into the wash still for the next pass. For most Scotch whisky, the middle cut is the final output: New make spirit. As with any pot still, the feints are too weak and are captured and recycled into earlier stages of the process. After the second distillation, the ABV is 65-70%, which strongly depends on the alcohol content of the low wines, which in turn strongly depended on the alcohol concentration of the wash.
Lowland Scotch Whisky and Irish Whiskey is distilled a third time, through a second spirit safe. The resulting new make spirit might be around 80% ABV. Since the spirit used to charge the second spirit still is already fairly concentrated in terms of ABV, this additional step doesn’t increase the ABV as much as the pass through the first spirit still did. Occasionally, Single-Malt Scotch Whisky is distilled a fourth time. Bruichladdich recently did this with their “X4 (Perilous Whisky).” The final ABV of that product was 90%…you can see that each step is giving diminishing returns in terms of ABV. On the other hand, there was enough Ethanol in this product to run a Formula 1 racing car.
Aside on ABV: A higher ABV has an interesting effect. Because alcohol’s boiling point is less than human body temperature, when a high-ABV whisky hits the tongue the alcohol “flashes” — it evaporates very quickly. This carries aromas to the nose that may not be obvious before you taste. Keep in mind that the ABV of the final bottled product is less than the ABV of the new make spirit that goes into the spirit safe because the aging process reduces the ABV by up to 3% per year in Scotland, depending on seasonal humidity and temperature variations.
The Basics of Distillation; Part 2
There are two key components to the pot still. The part where the liquids and solids are (the beery wort created by the yeast) and the vapors that come off of it. Remember, the contents of the still include proteins, amino acids, enzymes, carbohydrates of varying complexity, phenols, alcohols, dead yeast, acids, and other chemicals, not all of which are water-soluble to the same degree (if at all), and some of which are alcohol-soluble. It’s not a simple Ethanol+Water mixture. The goal of distillation is to separate the good stuff from the bad, in a way that is very repeatable. If you make whisky, you need to do this in such a way that each batch of each of your expressions tastes the same from one batch to the next.
It’s been said that Scotch whisky has been said to have over 800 unique chemical compounds within it that contribute to the flavor. Distillation is the process whereby those chemicals are delivered from the wort to the cask. The point of distillation is to produce a liquid with progressively less water (by volume) and progressively higher alcohol (by volume). The point of distillation of Scotch is not to produce pure Ethanol (grain neutral spirits). Pure Ethanol would taste like Vodka…perhaps even blander than that. Scotch producers (and whisk(e)y producers in general) want to preserve the impurities that give their product its unique tastes and smells.
Modern pot stills use integral steam pipes that indirectly heat the wort from within. A still can hold thousands of liters. The temperature is presumably kept below the boiling point of water, but I don’t know that for a fact. Traditionally, direct heat was applied to the bottom of the pot still, and regardless of the source, the heat causes the alcohol and other vapors to escape into the conical or cylindrical column above the liquid level.
As the liquid is heated, the vapors interact with the copper interior of the still, which is said to influence the flavor (no one is precisely sure what’s going on there). Some of the vapor condenses and interacts with the copper multiple times before the condensate is taken out of the still. Stills have various shapes and the surface area and angles are different, which again is said to produce different flavor profiles in the new make spirit.
At the top, there is a downward-angled tube that carries the condensate to the next step of the process (either the next still, or ultimately the spirit safe). The tube is called the Lyne Arm, and is depicted in this excellent diagram. That carries the vapor with its alcohols and aromatic compounds (some of which is presumably already condensed) to the condenser, where most of the condensate is produced. This article on stills lays out many different designs but uses no definitive language: What seems to be clear is that different shaped stills produce different qualities in the spirits, but it’s also true that the stills are not all using the same input. The scientist in me wonders if anyone has tried using an identical mash formulation into various shaped pot stills to see what the specific chemical difference is due to shape alone. Also I wonder what kind of product would emerge if copper were replaced by stainless steel, or glass, or any other chemically inert material.
Next, in part 3, I’ll get to the final specifics of the process: What is the point of multiple distillations? What happens in the first? The second? The third?
Tonight’s Dram
Highland Park 21
Sold Exclusively via Travel Retail
This is one of my favorites, and one of the best HP expressions I have ever owned. I hear that there is a -23 that is very good, but I haven’t had the pleasure. The -21 has the usual citrus notes you’d expect from Highland Park. In the nose I get a hint of peat with Tangerines and oaky caramels and vanillas with some wet leather and baking/mulling spices. On the palate there is a wonderful mix of oiliness and seawater (the texture is thin, yet it coats the mouth nicely). The finish develops over a few minutes and I get lovely peat in there with what can only be described as Apple cider or perhaps Quince. The finish has fruity/floral notes that are unexpected.
This expression is smoother than the -18 and I like it very much. You can get it at the SFO international terminal for $105 (price observed 2 months ago). It’s also available at LHR for £60. That’s where I got mine, through the efforts of a good friend.
The Basics of Distillation
Well, this has been much delayed, but I wanted to write down what makes distillation possible. It’s really not a complicated idea. The first part is what I already wrote about: You create a solution (somehow) that has a mixture of liquids with the idea that you want to separate them. Not all liquids are mutually soluble, but since water is known as the “universal solvent,” most things (solids and liquids) can be dissolved in water. Therefore a common task that needs to be done is to separate water from the stuff that is mixed with it.
Evaporation is the key to distillation. Moreover, another important point is that not all liquids have the same boiling point. Oh, and the fact that boiling is a reversible process. Let’s step back: You don’t have to boil a liquid for it to evaporate. A pot of water, left alone, will turn into an empty pot (if you are patient enough). If you enclosed that water in a vessel of some kind and applied heat to it, you’d be encouraging it to evaporate at a faster rate, up to and including boiling it. But remember, boiling is reversible. When the water vapor gets far enough from the heat, it will turn back into a liquid (i.e., it will condense).
If our imaginary vessel is big enough such that the water vapor can get away from the heat, it will condense on the sides and slide back down to the [still boiling] water. This brings up an important point: Such a vessel can’t be closed, can it? For most liquids, the space consumed by a vapor is MUCH larger than that consumed by the equivalent liquid. Thus a closed vessel would be under enormous pressure…probably dangerous levels of pressure. So the vessel will need to be open. Now, can we make the fact that a vapor wants to condense back to a liquid as it cools off work for us?
If the imaginary vessel has a level somewhat above the boiling water that is intentionally kept at a temperature less of 100 °C, the water will condense at that level. The act of changing phase back to a liquid will give off energy that will warm up the level, so it will take work to keep that level cool enough. I hated Thermodynamics in college, so I won’t even try to figure out how much energy this would take. Intuitively, it will take energy to keep that level at or below 100 °C.
When water is distilled (to purify it), the idea is that water vapor can be collected and condensed into “purer” water, leaving behind the impurities that might have been dissolved solids, and perhaps other liquids. Any liquids that boil at a lower point than water will be in the mix as well, unless great care is take to make them condense at a lower level, so the vapors that reach the water collection level are mostly water.
Separating liquids is easier when they have significantly different boiling points. For instance, Ethanol (78.4 °C) and water (100 °C). It’s not a perfect matter of just “boil the solution and catch everything that condenses at the desired boiling/condensing point temperature” because the vapor is a mixture of gases and the condensate won’t be a perfectly pure, isolated liquid.
Think about it: Even without applying heat, some of the water is vaporizing (evaporating) anyway. A glass of Scotch will have Ethanol wafting away even when you are not trying to boil it (don’t boil Scotch in my presence, please). Trust me on this, even though you can’t smell it, water is wafting away as well. And those other smells? The volatile compounds that make up the pleasing aromas and flavors? You can smell them because they are leaving the glass. When a Chemist says “volatile” they are referring to a tendency to evaporate. Common usage seems to equate volatility with inflammability, but that’s a different adjective entirely: Inflammable.
The trick with distillation, since it’s hard to get what you want after only one pass through the still, is to take the result and distill it further. After one pass, the distillate is not perfect, it’s perfected: It’s closer to where you want to be than whatever you started with. That’s what is done in the production of whisk(e)y.
Scotch is typically distilled twice, but some are triple distilled (makes the initial new make spirit higher ABV, compared to a double-distilled product, but the initial ABV and the bottle strength have no relationship with each other due to aging, mixing with water, etc.). As an aside, most Irish whisky (I’m particularly fond of Bushmills 16) is triple-distilled.
Bruichladdich has created a quadruple-distilled monster called “X4” that is nicknamed “Perilous Whisky.” When it went into the casks it was over 90% ABV. As a publicity stunt, they used X4 as fuel in a racing car. Seriously. Aside: I object to the plan to mix it down and sell it at 50% ABV. It’s closer to single-malt vodka. Come on…Glenfarclas makes a 60% ABV cask-strength expression. At least go for 66% ABV.
Now that some of the more mundane aspects of distilling are behind us, I’ll take a look at how a pot still actually works.
A Funny Thing Happened on the Way to the Forum
Many of you might know that I am moderately active on the Whisky Magazine Forum (sometimes abbreviated as WMF). I was recently invited to join a new forum, populated by many of the denizens of the WMF.
Please accept my invitation to join the new Whisky Whisky Whisky forum and help make it *the* place for whisky discussions on the web.
The other forum that y’all might find interesting is on LinkedIn. There is a group there called “Whisky Enthusiasts” that is open to anyone on LinkedIn. There are also perhaps two dozen whisky groups on Facebook (there may be more…). It will take a while, but I’ll gradually post this message on them.
If anyone reading this knows of any other fora related to whisky, please post a comment here.
Such a Deal I Have for You!
I was at the Costco in Redwood City, CA yesterday and I always look over their liquor selection whenever I am in the store. I found the Glenlivet Nadurra 16 a few months back for $42. That was before it won a bunch of awards. That was a pretty good deal: Beltramo’s has it listed today for $49.89, and their prices are usually good, so Costco’s price was comparable (especially since I’d expect a lower price at a discount store).
Yesterday I saw a stunningly good price on a lovely holiday gift: The Glenlivet Master Distiller’s Deluxe Tasting Kit for $75.99. As you can see if you follow that link (sorry…no picture), the comparable price is over $100.
The kit contains:
- One bottle of Glenlivet Nadurra 16
- One bottle of Glenlivet French Oak Reserve 15
- Two George G. Smith nosing/tasting glasses (Glencairn-style)
George G. Smith was the founder of The Glenlivet distillery in 1824.
This item is clearly a good deal: The current price of the Glenlivet French Oak Reserve 15 at Beltramo’s is $37.89, so the price of the whisky alone in this gift package is $87.78, without including the cost of the glasses. Similar crystal Glencairn-style nosing/tasting glasses at the Malt Advocate’s web site cost $25 a pair. My best guess is that retail price of this gift package’s contents, if purchased separately, would be about $110 (in line with the link above; so this package is discounted at about 30%).
Contact me by email if you want to send me one of these gift packages. 
In all seriousness, make sure you take advantage of this offer and share a couple of excellent single malts with someone you care about.
WhiskyFest San Francisco 2008 — The Final Word
Well, I’ve dragged this out long enough. As I said earlier, my priority at WhiskyFest was to hit the Bruichladdich booth and then I went to Highland Park (I did a vertical tasting of 12, 18 then 30; I wanted to taste the new 40, but it wasn’t on offer) and stopped to see my friends at the Beltramo’s booth. After that, I stopped at Ardbeg and tried the only expression I don’t own, the Airigh Nam Beist (Gaelic for “shelter of the beast”). So…I started on Islay and worked my way out. I was sad to note, when I did get “off the island,” that The Dalmore wasn’t present in their assigned booth. They are one of my favorite Highland distillers.
The standout product of the whole night, for me, was the “Sam Houston” small-batch bourbon from McLain and Kyne. This was buttery, spicy, and sweet. Excellent mouth feel and just overall a superb bourbon. Highly recommended! I also tasted, and really liked, the newly released Eagle Rare 17 bourbon from Buffalo Trace. Not only is it a fantastic bourbon, it’s a great price (well, prices are going up all over, so this might not be as true anymore as it was a year ago when I got a bottle of the Eagle Rare 10 for $29). BTW, if you’ve ever wondered about the origin of the name “Buffalo Trace,” there is an excellent wikipedia article about it.
Throughout the night (we were there for about 2.5 hours) we stopped at the following vendors: Zacapa Rum, Glenfarclas (I love the 105 degrees proof…smoothest whisky at 60% ABV you’ll ever try!), Compass Box (the new Peat Monster is much more well-balanced than its name would suggest; one downside: It’s sold in an impractically large 1.75 litre bottle that will definitely stand out on your whisky shelf!), Bowmore, The Glenrothes, Isle of Jura, Knappogue Castle, McLain and Kyne (where I tasted the Sam Houston), Canadian Club (they didn’t have the 30-year anniversary expression yet 
), Bunnahabhain, Bushmills, Ardmore, Laphroaig, BenRiach, and The Macallan.
The event was definitely better than last year (not that last year’s was bad…): Better hotel, better food, better selection of vendors, and better attended. I have to assume they’ll be back in 2009 for the third annual WhiskyFest San Francisco. I can’t wait!
Whisky in Las Vegas: Not So Much
At least…not for me.
Oh, I’m sure it’s here somewhere. I had a relatively nice dinner last night in the MGM Grand at Emeril’s New Orleans Fish House and the restaurant’s whisky selection was extremely pedestrian. They didn’t even have a decent selection of Bourbon or Rye whiskey! (In retrospect, I maybe should have ordered a Sazerac, but I opted for a Vesper instead…the smoothest type of martini, IMHO, and it went great with the gumbo! Now that I think of it, based on their whisk(e)y list, I’m not even sure they had the ingredients for a Sazerac on hand.)
The only thing remotely interesting on their whisky list was The Dalmore’s Cigar Malt (which was excellent with the bread pudding for dessert!).
I can’t wait to get home tomorrow night!
Whisky? Whiskey? Yes, Please!
Which is it? Whiskey or Whisky? The short answer is that Scotch is always whisky (plural: whiskies), and Irish is always whiskey (plural: whiskeys). I find it interesting that the plural of Irish whiskey is an odd construction (the suffix -ies seems much more natural than -eys). Indian, Japanese, Canadian and Welsh products are whisky, spelled like Scotch, and Americans produce whiskey (with an ‘e’); the latter being Bourbon, Corn or Rye. In North America, exceptions to the rule are more common, but in the rest of the world, people pretty much spell whisky without an ‘e’ in the word.
The wikipedia has a very nice summary of the usage and history of the presence (or absence) of the ‘e’ in whisky. Turns out that the ‘e’ might have been added to distinguish other whiskeys from Scotch, which at the time (19th century) was a very poor-quality product. A politically incorrect joke is that a Scot decided to save ink (they are reputed to be famously “tight” with money) by reducing the number of letters in the name of the product, thereby saving about 14% on ink (i.e., 6 letters instead of 7).
To avoid confusion, regardless of which kind of whisk(e)y you are referring to, they are both pronounced the same. And…they both rhyme with Bruichladdich.
