Theory of Distilling Volume 1: Basic Ingredients and Process
Distillation, and the theory of home distillation, is a widely known and narrowly understood process. For us homebrewers, it seems like it’s more magic than science, even though it’s just one extra step above and beyond the brewing process. This week, we’ll go over some of the basic distillation processes, what your base ingredients add, and hit some of the high notes of wood aging and making a clean product!
What Exactly is Distilling?
I think that Will, one of the owners of 10 Torr Distilling and Brewing, put it best when told me that distillation is a basic separations process. Whether you’re separating alpha acids from hops or ethanol from a fermented solution, what you’re really doing is separating, concentrating and ideally collecting specific compounds. Our favorite example of this is, of course, the distillation of spirits.
When we look at distilling something fermented, there’s some basic terminology to keep up on. Whether the base is grain, fruit or molasses, the resulting ‘low wines’ are called a ‘wash’, just like fermenting beer is called ‘wort’, or fermenting wine, cider or mead is called a ‘must’.
Once you put your wash into the still and begin the Run (which is what we call the process of running the wash through the still), there are five basic parts, or cuts, that you are looking to separate. The very first compounds, those with the lowest boiling points and generally considered some of the more volatile components are called the Foreshots. These consist of some of the higher alcohols, primarily methanol, or wood alcohol, depending on the wash. These not only give you wicked headaches and hangovers, but are literally poisonous and very dangerous to ingest. When you hear of people going blind from drinking backwoods moonshine, this is usually the main culprit. Most distiller’s, depending on their process and the ingredients of their wash, will toss a small amount of the first liquid to come off of the still to compensate for these nasties. For example, if you’re doing a grain wash to make whiskey (or whisky, respectively), there are relatively low amounts of methanol, so you can lump that first part into the heads. If you’re making apple brandy, a wash that consists of cider or a fermented apple base, you’ll want to separate out the foreshots, as fermented apples create a huge amount of methanol, and it’s very dangerous once concentrated by a still.
For most grain based washes, it’s easy enough to lump the Foreshots in with the Heads. The Heads cut consists of many of the higher alcohols and ketones, such as acetone and acetaldehyde. Heads, while you don’t want to drink them, don’t necessarily need to be thrown away. More on that in a paragraph or two! These will also give you awful hangovers, especially the acetaldehyde, so you’ll want to set these to the side.
The Hearts Cut, or Middle Run, is the whole reason that spirits are a thing. This is the best and purest part of the wash, the ethanol we’ve worked so hard to create. This is what you will barrel age, drink straight, or mix into your cocktails. This is what we’re really trying to collect.
The Tails Cut contains fusel oils that add to flavor, but also add to the overall ‘impurity’ or a spirit. The trick is to get just enough in the finished product so that flavor comes through, but not so much that it turns cloudy or seems watery. If you let your still run too far past the Hearts part of the Run, you’ll get tons of flavor at the expense of the overall quality of your product.
Finally, the Feints (or Faints, if you’d like). This is the collection of everything but the Hearts. This is generally saved and put into the next Run, as it contains ethanol that can bolster your next Run once it’s diluted into the next wash. This is a common practice that can increase overall yield.
Types of Stills
While there are many brilliant designs and innovations, when it comes to making spirits, there are two primary types of stills: Alembic and Reflux. Alembic stills are engines of simple distillation, most commonly known for making Scotch Whisky, American Whiskey, and just about anything that starts with a grain base (more on types of distillates in a minute). These ‘Pot Stills’ feature less reflux action, the process of purifying the spirit in the column before it’s condensed, and therefore let more compounds mix into the Hearts part of the run. While that definition is a little simplified, it’s no less true. Alembic stills will generally produce, at the high end of the hearts run, a distillate from 120 to 160 proof, or 60% to 80% alcohol. While that doesn’t sound like a lot, keep in mind that most commercial spirits are ‘Proofed’, or diluted, down to 80 proof, or 40% alcohol by volume.
The magic of an Alembic still is the flavor that it let’s through. You can literally taste the grain or, in the case of a Pot still distilled rum, the molasses or the cane sugar. Because the distillate isn’t as pure, more of the flavor compounds created in the original wash are transferred into the finished product. These compounds play well with oak aging, and create truly unique products that we all know and love….like whiskey as whole!
Reflux stills come in many shapes, sizes and subcategories, but the overall concept is the same. As your wash evaporates, different methods ensure that the majority of the evaporate gets condensed inside the column, creating a chain reaction of condensation that condenses evaporates under the 173° ethanol evaporation temperature and forces them to fall back down the column and back into the boiler to be evaporated again. This means that compounds like heads don’t get through, creating the purer distillates, such as vodka and gin-base. We like to call these the odorless-colorless distillates, because that’s the ideal!
One of the coolest, and very common commercially, designs of reflux stills is a fractionating or fractionation column. You see these everywhere, and the design is simple and brilliant. Each one of the windows (see picture above) is preceded by a plate. These plates are full of ½” by ¼” reducer couplings (this will definitely vary still to still, but this is a common example), pointed with the ¼” side up and set in at about halfway in the plate. As the alcohol and other compounds evaporate, some of the evaporate makes it through the couplers, while the rest condense when they hit the plate above them and drop back down to the plate below. The result of this is that every plate section is distilling the wash literally hundreds of times, and the more plates, the purer the product that comes.. Cool science, right?
The moral of the story is this. If you want to make whiskey (or whisky if it’s Irish or Scottish), then you want an Alembic still. Even rum has an amazing flavor, but can be done on either type of still. Want to make vodka, gin, or even brandy? You’ll want a purer product, and reflux is the path.
Let’s Talk Ingredients
While, just like with beer and home brew, there are many different styles and considerations for distillates, the basic types are based on what you made your wash from. Without overcomplicating it, it goes like this:
- Grain Base = Whiskey or Whisky
- Fruit Base (including grapes) = Brandy
- Processed or Unprocessed Sugar Base = Rum
- Agave or Cactus Species = Tequila or Mescal, respectively
- Anything At All Base Distilled at 190 Proof (95% abv) During the Hearts Cut = Vodka
Notice that vodka gets the ‘anything goes’ label. This is because, traditionally, vodka has been made from just about everything, from potatoes to rye to American 2 Row. Vodka is all about process, and to be considered vodka, it has to be about as pure as is possible, coming off of the Hearts run at 95% abv. Even if this means running it through a pot still three to five times!
The base ingredients will always add their own flavor, which is why it’s always important to use the best you can get. If I can paraphrase two of our local distilleries, both Colby at Frey Ranch Estate Distillery and Melissa at 10 Torr Distilling and Brewing (check out our video with Frey Ranch HERE and our video with 10 Torr HERE!!) you can’t put crap into your still and get get magic out of the other end. Base ingredients will always play their part, and the better ingredients you use, the better your finished product.
Your recipe will always matter as well, but not as much as the quality of the base ingredients. If your Bourbon recipe consists of 75% corn, 13% rye and 12% barley (one of Heaven Hill’s famous Bourbon’s malt bill), and you’re using feed corn, rye seed for cattle, and home malted 6 row barley, you are going to be very disappointed in the finished product. Alternatively, if you use high end corn, quality malted rye or flaked rye, and some high enzyme American 2 Row, you will get a distillate that is as good fresh out the still as it is after wood aging, and shelves and shelves above the feed version of this recipe.
The Magic of Oak
No matter what you’re making, oak is the way and the path. While some spirits, like vodka, are not traditionally barrel aged, if you look at high proof products made in with fractional distillation like brandy or cognac, the clean spirits still take on some pretty incredible oak characters.
For commercial distilleries, 53 gallon barrels are the ideal size. The surface area to volume ratio is perfect for long term aging, letting the spirit get just the right amount of flavor and barrel compounds from the wood without sacrificing too much of the spirit to the angels.
Inside of the barrel, several things are happening. The ethanol in solution, ethanol being the great solvent, is slowly but consistently dissolving the inner layers of the charred wood on the inside of the barrel, releasing flavor compounds like vanillins to become part of the spirits. At the same time, the charcoal (think carbon) created from the charring of the wood is absorbing any impurities left from the cuts. While all this is going on, the barrel is also ‘breathing’, or expanding and contracting with the ambient temperature, so it’s also absorbing and squeezing out the spirits, further adding to the compounds being dissolved into the spirit.
A lot going on, right? On top of all of that, evaporation is happening! In more humid climates, ethanol is evaporating, hence the term ‘Angels Cut’, slightly diluting the overall spirit. In arid climates, water is actually evaporating, which concentrates the spirit in the barrel.
Now you can see why the process of barrel aging is considered magic! But what about those of us who want to try wood aging, but don’t necessarily produce spirits 53 gallons at a time, much less have access to barrels? The solution is putting the wood in the spirit instead of putting the spirit in the wood! Using Wood Products produced from charred barrels, we can replicate the magic of a barrel in as little as a quart at a time!
There are many different types of oak products for aging smaller batches, and the main thing to remember is surface area. Everything else can be replicated within reason, from evaporation to breathing, but the surface area of different oak products will be what you have to play with to get the spirit you want.
Oak Chips have the most surface area of the available oak substitutes that you’d want to use. This means that they give up what they’ve got MUCH faster and need to be monitored more closely. Oak Cubes have a much more consistent surface area, and can be more predictable, albeit they impart their magic more slowly. While they do come in a variety of flavors, my favorite are the Hungarian Oak Cubes you see in the link above. They cover all of the flavor bases between American Oak and French Oak while imparting the best parts of a #3 Char, also known as medium char, one of the most commonly used levels of char in the American Whiskey industry.
Oak Spirals may be some of the most versatile of the available oak substitutes for those of us practicing home fermentation and aging. They come in every level of char, each of which produces distinctly different flavors, and in both American Oak, which is more forward and in your face, and French Oak, which is more subtle and complex. Spiral will also inpart their magic slower than chips or cubes, so be ready for the long haul!
Is Home Distillation Legal?
Before the next installment of the Theory of Distilling, let’s address the elephant in the room! On the federal level, distillation of your own spirits at home is very illegal. This dates back to prohibition, and there is literally no way around it. Every state has different laws regarding home distillation, but it remains a big no no on the federal level. Something to keep in mind as you journey down this theoretical road!
Thank you all for reading! Please post questions and comments below and we’ll keep this conversation going! Don’t forget to watch our interviews with commercial distilleries on our YouTube Channel, BrewChatter TV, along with a ton of other fun and informative videos! Connect with us on Facebook, Instagram and Twitter to keep up on fun fermentation subjects and don’t forget to Brew On!!