If you want to produce your own spirits at home, you need to distill them using a still.
But what is a still? How do they work? And how can you find the right still for you?
In this article, we’ll tell you everything you need to know about stills – how they work, the available varieties, and how to use them to produce great-tasting spirits.
Table of Contents
What is Distillation and How Does It Work?
Distillation is the process of separating a mixture of 2 substances so that you can extract one of them from the other.
When alcohol and water are mixed, for example, you can’t just pick out the alcohol. Since they are both equally liquid, you can’t filter or strain them apart, either.
What you can do, instead, is heat the mixture to a specific temperature, where one of the components of your mixture will start to boil and the other won’t.
For example, the boiling temperature of alcohol (ethanol) is about 80 degrees Fahrenheit or 26.7 degrees Celsius, whereas the boiling temperature of the water is 100 degrees Fahrenheit, or 37.8 Celsius.
Therefore, if you heat the mixture to a temperature inside this range, it will boil, but the bubbles that form will be primarily made up of ethanol gas rather than steam. The alcohol molecules vaporize before the water molecules, so alcohol steam rises above the water, where it can be recondensed into a purer liquid form.
This is the primary principle of distillation – that a difference in boiling temperatures can allow you to extract a substance from a mixture, and we use it in several ways.
What Are the Applications of Distillation?
We use distillation every day industrially to create all kinds of products – not just alcohol. Stills allow us to extract valuable substances from mixtures in factories as well as breweries.
Petroleum
Oil and gas don’t come out of the ground in a form that you can pump into your car. Instead, they need to be purified in several ways, including being distilled.
Crude oil is a mix of different hydrocarbons that need to be distilled into “fractions”, or categories of broadly similar hydrocarbons. This is done by running the mixture through a distillation column, or still.
Alcohol
Liquor of all kinds is made by distilling alcohol from a fermented mixture that includes a lot of water and other ingredients. Since alcohol boils earlier than the other components, it can be extracted through distillation.
Essential oils
Distillation isn’t the only way to extract essential oils, but low-pressure steam distillation is a popular technique. The herbs and aromatic plants are exposed to steam in a still that recondenses into an oil and water mixture that is easily separated.
Hydrosols
Hydrosols are plant extracts much like essential oils but are milder in scent and used to create aromatic waters. They are extracted from fresh or dried botanicals. The higher water content in hydrosol means that stills producing hydrosol don’t have to be as efficient.
A Brief History of Distilling Spirits Around the World
Distillation is a curious human invention that initially had nothing to do with producing alcohol, and everything to do with turning lead into gold.
Alchemy is the reason we have liquor and spirits. Before modern chemistry, alchemists were obsessed with understanding how substances work and how they can be transformed. The invention of the still came from these inquiries.
The first historical mention of distillation references the first western alchemist, known as Maria the Jewess, as the inventor of the tribokos – the 3-armed pot still, in the 4th century AD.
In the 8th century, Arabic alchemist Abu Musa Jabir ibn Hayyan invented the alembic pot still that ultimately led to a widespread revolution in distillation. Interestingly, he did not have alcohol in mind at all when he invented it, and the first applications were mostly medical and scientific.
In the 17th century, we see the first textual historical evidence that people were drinking and enjoying distilled liquor in a form similar to the one we enjoy today – calling it aqua vitae, or water of life.
How Does a Still Make Alcohol?
A still doesn’t actually make alcohol – it just separates it from everything else.
Alcohol is created through fermentation, first. This process happens when sugar is broken down by micro-organisms like yeast into alcohol. It happens naturally when yeast is introduced into an environment with lots of sugar or starch to break down, whether that sugar comes from molasses, fruit, potatoes, or granular sugar from a bag.
Once the fermentation process has progressed far enough, the alcohol exists inside the wash and just needs to be extracted. That’s where a still comes in – helping you separate the alcohol from the other ingredients in the mash.
How Are Different Alcohols Distilled? (The Basics)
Whiskey
Whiskey is made from a fermented mash of grains like corn, rye, and barley. These are allowed to ferment before they are distilled in copper stills, and aged in wooden barrels, commonly oak. This imparts an extra layer of flavor.
Rum
Rum starts as sugarcane molasses or sugarcane juice that is then fermented and distilled. The liquor is usually then aged in wooden barrels for different lengths of time and may appear dark, amber, light, or white. Read more on how to make rum here.
Tequila
Tequila comes from the webber blue agave plant, a succulent also called agave tequilana, that grows in Mexico where the liquor originated. Inside the agave plant, there is a bulb called the piña. This is baked and then juiced, and the juice is fermented to produce the base for tequila. You can read more on how to make tequila here.
Vodka
The secret to vodka is NOT bringing in too much of the flavor of the base, making vodka distillation a little bit different from other liquors. Although it is popularly believed that potatoes are the base for vodka, this isn’t very common. Grains like rye, barley, corn, wheat, or rice are used to make vodka, which is then double or triple distilled to produce pure, clear alcohol. Here’s our guide on how to make vodka from potatoes.
Gin
Gin is produced by distilling flavorless grain alcohol with juniper berries and other herbs to create the characteristic flavor of gin. The base for the alcohol could be anything. The juniper berries and other botanicals can be added to a thumper to flavor the alcohol without cooking them into the mash.
So, What is Moonshine?
What is Moonshine? Moonshine generally refers to illegally produced, high-proof, clear grain alcohol.
In purist terms, moonshine is an un-aged whisky made from corn mash and distilled.
However, some people make moonshine from sugar to reduce the corn taste so that their moonshine can be otherwise flavored, and people use other kinds of a base to produce high-proof grain alcohol, that they call moonshine.
We’ve written this guide on how to make a corn-based moonshine here.
What Are The Different Types of Stills, and What are They Used For?
Pot Stills:
The oldest still design is still one of the most popular, especially for liquors where you want the taste of the base to come through.
A pot still heats the mash and channels the vapor that rises into a swan neck that leads to a thumper, or directly into the cooling worm, where the final product comes through a spigot.
A pot still doesn’t extract that much alcohol by volume (ABV), so if you want the purest alcohol it isn’t necessarily the most efficient design. You would have to run the entire mix through the still several times to get “double distilled” or “triple distilled” results.
However, if what you want is a liquor that carries some of the flavors of the base, you probably don’t care about ABV as much as you are concerned with how the final product tastes.
A pot still is ideal for whisky and rum – dark, distilled liquors that will be aged in wooden barrels. Ideally, some of the flavors of the mash will transfer through to the final product, and that’s a good thing.
Column Stills:
The column still was patented by Aeneas Coffey in 1830 and represents a newer generation of more efficient stills.
This doesn’t mean they are necessarily better than pot stills, but they produce more alcohol by volume (ABV) at a higher rate of efficiency.
A column still is constructed vertically, so that vapor rises and is restricted by layers of filtering columns. The pure alcohol molecules can rise to the top where they meet the condenser, whereas steam and other congeners (stuff that isn’t alcohol) get stopped and fall back into the wash.
The result is that what condenses is much purer than what you would get from a pot still, and many of the congeners that would contribute flavor are filtered out, so the final product has less of the flavor of the mash.
Column stills are perfect for pure alcohols, in which you don’t want to taste the base, like vodka or tequila, although they can also be used to make whiskey or other flavorful alcohols when used in certain ways.
Continuous Stills:
Pot stills are run in batches. If you want to double distill something in a pot still, you need to transfer the results from the cooling worm back into the pot and repeat the process.
In a column still, there is no need to batch like this. Instead, you can run the still continuously by feeding a steady stream of fermented wash into the still, and continuously bottling the distilled liquor that is produced.
Of course, in continuous stills, it is incredibly important to monitor all of the levels and temperatures. There is no set-it-and-forget-it way to continuously distill spirits, and in commercial distilleries, the constant monitoring of continuous column stills is a stressful, full-time job.
Pot Stills Explained:
Whiskey Stills:
The preferred still for whiskey is a copper pot still. There is a sulfur taste that can arise when using stainless steel, so copper works much better.
Whether it is Scotch, Irish Whiskey, or Tennessee Whiskey, you want a pot still without reflux so that lots of the flavor of the wash comes through, but without the sulfur taste.
Some commercially available whiskeys are made in large distilleries with column stills, but in general, the best results come from a copper pot still, which transfers the purest flavors into the final product.
Gin Stills:
Gin is produced from a mash of grain alcohol that is then flavored with herbs and botanicals.
You can produce gin in any kind of still, and historically different styles have resulted. The original gins made in pot stills had more of the base mash in their flavor, while later gins used reflux condensers to reduce some of that flavor, allowing them to add more botanicals and creating the London Dry style gin.
Some gin stills introduce a copper basket in, the pot, so the alcoholic steam rises through the botanicals, infusing it with flavor. Other gin still setups do this by placing juniper and herbs into the thumper.
Thumpers:
A thumper – also called a thumper keg, a thumper barrel, or a doubler – is used primarily to speed up the distillation process for pot stills by removing the need to distill a second time.
A thumper is a second still, 25-40% of the size of the main still, where alcohol vapor falls into a second mix and then rises again through residual heat to condense into the worm cooler, where it is released through a spigot.
Traditionally, distillers have added either spirit tails from a previous batch, current mash, or water to the thumper to help cool the alcohol vapor. The highest ABV results are achieved by adding pure alcohol to the thumper, drastically increasing the proof of the resulting spirits.
Thumpers can also be used to add flavor. The alcohol vapor travels through the thumper and picks up flavor there, so it is a place you can add herbs, botanicals, or other flavorful ingredients that you want to flavor your spirit.
Column Stills Explained:
What is Reflux and Why Do We Need It?
In reflux distillation, reflux is a segment in which vapor is cooled, causing it to return to the still.
Without a reflux condenser, the alcohol vapor would build up at the top of the still and create pressure there, which could potentially be dangerous, and the vapor would not recondense so that it can be captured.
Using reflux allows a column still to achieve a kind of equilibrium so that alcohol molecules reach the right level so that condense, fall, and be captured.
Plate stills
A column still that uses plates to limit the upward movement of vapor is called a plate still. There are a variety of different kinds, the simplest of which are just stainless steel or copper plates with holes in them, through which condensed liquid falls back into the still.
What are Bubble Plates?
Bubble plates are so-named because they have bubble caps in the center of their plates – a raised section where the vapor rises in the middle and then must condense to fall back down onto the edges of the plate.
Some plates have multiple bubbles, while others have just one.
Bubble Plates vs. Packed Columns
There are advantages and disadvantages to both methods, but these are largely procedural and you can make great distilled liquor either way.
Bubble plates are especially efficient for larger stills and commercial distilleries. They are sometimes more expensive to set up initially, but they are tremendously reliable and they don’t need to be cleaned or maintained as often as packed columns. You can use as many bubble plates as you want.
In contrast, packed columns are best for home distillers and small stills with columns less than 4 inches in diameter. The packing has more surface area than bubble plates and should be regularly cleaned. However, packed columns can be adjusted easily.
If you are committed to producing consistent, high-proof spirits in your column still, it’s better to use bubble plates. However, if you are a hobbyist who wants to switch things up and occasionally produce more flavorful spirits, packed columns allow for more versatility.
Vapour Management Stills (How Do They Work?)
Vapor management stills are constructed to allow users to direct the vapor to control the rate of redux and capture.
A common design is a packed column with a T-shaped attachment midway up the column that redirects to a secondary product condenser. A gate valve is used to control the flow of vapor to the secondary condenser.
Typically, the still is run for about a half-hour with the gate valve closed to create an equilibrium where lighter alcohols rise to the top of the column and heavier alcohols fall to lower levels.
The valve can then be partially opened to allow the vapor to flow into the secondary condenser and drop down for collection.
An important note: the reflux condenser at the top of the column must be open to the air and not sealed, otherwise pressure could build up to explosive levels. Alcohol will not evaporate through the top of the column if the condenser is working properly.
Liquid Management Stills (How Do They Work?)
Liquid management is all about controlling the flow of the liquid distillate out of the system, typically using a needle valve.
In a common design, slanted plates above the packing are positioned so that distillate catches on them and drips from a top plate to an overlapping bottom plate, which leads to the needle valve.
Keeping the valve closed initially helps the column reach an equilibrium with higher alcohol levels and lighter alcohol molecules catching on the plates. Since the level of outflowing distillate is what is controlled, this technique is “liquid management.”
Cooling Management Stills (How Do They Work?)
Cooling management stills use the temperature of the water that runs through the reflux condenser to control the outflow of distillate.
Instead of using the reflux condenser to knock down every molecule that reaches it, cooling management separates alcohol molecules by allowing only these to rise above the reflux condenser into a secondary product condenser.
The valves are closed so the system can reach equilibrium before the temperature of the water running through the reflux condenser is gradually decreased. The result is that only alcohol molecules can get to the secondary reflux condenser and are released as distillate.
Hybrid Stills
Some stills are designed so that they can be used in multiple ways and configurations, giving you the maximum amount of flexibility.
The most common form of hybrid still is a column still with removable packing and plates, so that it can also be used as a pot still.
What Factors Should You Consider When Choosing a Still?
Dimensions
Stills are sizeable, even for home distillers, and when filled with wash they can be extremely heavy. However, this size might be necessary if you want to produce a certain volume.
Before you make any decisions about the kind of still you want to buy, examine the space you will be using and determine how much room you have and how you can arrange it.
In designing your still set up, think about what you want to produce and the resources you have both spatially and monetarily to facilitate that.
Boiler and Heat Source
Controlling the temperature levels in your still is crucial to achieving a good result. Although in days past there were moonshiners who would heat stills over a wooden fire, methods like this are extremely rare now because there is so little control over the temperature.
The best solution for home distillers and small commercial distilleries alike is an immersion heater than can be directly inserted into the still and controlled electronically to maintain the ideal temperature.
A close second best is a quality electronic hot plate that can support the still. These can be controlled very accurately to maintain the right temperature.
Column size and throughput
For continuous distillation in column stills, column size becomes a factor that determines how much and how fast you can produce distillate.
Length affects purity and diameter affects speed. That is, the longer a column still is the purer the alcohol you distill will be, and the wider the tube, the faster you can produce.
For a column with a diameter of 2″, a 36″-50″ length is recommended. Wider diameters are generally matched up with longer lengths.
What Sort of Stills do Commercial Distilleries Use and How Big are They?
Commercial distilleries use the same basic styles of still that home distillers use, just on an industrial scale with many more controls.
The majority of commercial distilleries use continuous column stills to produce high-proof liquor in large volumes. This is true even for some spirits that are traditionally produced in pot stills. However, some companies do use massive pot stills to maintain the traditional methods of distillation.
Commercial distilleries use much larger stills than home-distillers do, to produce a lot more product. Some commercial column stills are more than 20′ tall, with kettles that hold hundreds of liters.
Frequently Asked Questions:
Q. Why Is It Called a Still?
The word “distillation” came before the word “still.” A still is “something that distills” so people naturally came to call it “a still.”
Q. What is a Whiskey Still?
A whiskey still is a still that is used to make whiskey – usually a copper pot still, to reduce the sulfur taste and produce a spirit that carries some of the flavors of the mash into the final product.
Q. Is Moonshine Made in a Still?
Yes. Moonshine is a classic example of a homemade liquor that is distilled in a still. It’s impossible to make moonshine without using a still, and all forms of moonshine are distilled.
Q. Why Do Stills Explode?
In the era of prohibition, moonshiners constructed their makeshift stills by welding together materials, and these unsafe stills did sometimes explode, but this isn’t at all common in the modern era with commercially built stills.
Explosions can happen, if alcohol vapor leaks out of the still and reaches a spark to ignite. It could also theoretically happen if the reflux condenser doesn’t knock down all of the molecules and pressure collects at the top of a column still.
However, if you have a commercially built still and you operate it according to the instructions, there is no need to worry about explosions.
Q. What is the Best Still for Home Distilling?
The best still for home distillers is the one that suits you best.
If you know you want high-proof, flavorless spirits then you should go with a column still. If you want to brew rum or whisky, a pot still might be a better choice.
It’s hard to go wrong with a hybrid still that can be arranged as a pot still, or packed and outfitted with a reflux condenser to produce higher ABV spirits.
Sources:
https://www.labmanager.com/insights/the-science-of-fermentation-1432
https://www.australianhomebrewing.com.au/learn/spirits/how-a-still-works/
https://winning-homebrew.com/what-is-a-thumper-keg-and-how-does-it-work.html
https://homedistiller.org/forum/viewtopic.php?f=1&t=35332
https://homedistiller.org/forum/viewtopic.php?f=1&t=46605
https://diydistilling.com/distillery-heating-sources/
https://www.reddit.com/r/firewater/comments/5gaq4p/how_much_does_column_length_impact_the_final/
https://www.ace-chn.com/knowledge/Pot_still_VS_Column_stills.html