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How Whiskey Is Made

Booze – The nickname came from a Philadelphia distiller name E.C. Booz, often mistakenly taken for the eponym of the modern term “booze,” had his name, address and the date 1840 blown into his dark brown-and-green quart container.  Booz bottles were shaped like little houses, with a sharp peaked roof.[5]

Bootlegger – The term “bootlegger” most probably dates to the Civil War when peddlers who sold illicit bottles of booze to soldiers are said to have hidden the bottles in the tops of their boots.[6]

Early "moonshine" Process Whiskey taste great but it is not a simple product to make. The following is my attempt to explain the steps that go into making with wonderful product.   

Whiskey (Ethyl Alcohol) begins with complex starches in the form of corn, rye, barley and sometimes wheat. These grains which are all complex starched need to be broken down into a simple sugar and then the sugar is fermented to convert it to alcohol. That sounds simple but it really is fairly complex.

We begin with barley which needs to be allowed to geminate or flower to begin the process. The malted barley and the other grains, i.e. corn, rye or wheat, are all sent through a grinding mill to form powders. Then the grains as powders are placed in water and cooked. The purpose of this is to allow the natural enzymes (proteins) that are in the gains to begin the process of breaking down the complex starches into simple sugar.    These grains contain three very specialized enzymes, each acting in different way on the grain.

    1st The enzyme Amylase breaks down the starch into Dextrin.

    2nd The enzyme Diastase breaks down the Dextrin into a sugar, Maltose.

    3rd The enzyme Maltase breaks down the Maltose into a simple sugar, Dextrose.

These enzymes are natural constituents of grains and some other starchy foods.

Once the grains are turned into Dextrose they are ready to be fermented. The dextrose which was prepared in a mash tub is transferred to a fermenter for processing. In the fermenter, yeast is added. Yeast is a tiny microscopic plant that thrives in sugar solutions such as fruit juice. Under the right conditions and in the presence of food, the yeast will subdivide and multiply many times over. Certain yeast as they consume sugar, will give off Alcohol and Carbon Dioxide. The yeast will consume all sugar available until they have polluted their environment with alcohol until they can no longer function. At about 16% alcohol by volume, yeast stop functioning whether sugar is present or not.

In order to raise the alcohol content above 14% to 16% it must be concentrated through distillation. Distillation or rectification as it is sometimes called, separates the alcohol from the other liquids and solids that make up the converted mash. This converted mash is called beer and in essence is the same as the bottled beer we drink. The beer is heated to the point where the alcohol boils. Fortunately alcohol boils at 172.9 degrees Fahrenheit, while water, the other main liquid in the beer boils at the higher temperature of 212 degrees Fahrenheit. Any solids in the beer are left behind during the boiling process.  As the alcohol vapors are given off during boiling they are collected and passed through a cooler, The cooler condenses the hot vapors back into a liquid, minus most of the water. From here the alcohol is ready to use.

However, if we are making whiskey or better yet, Bourbon, the condensed alcohol is very harsh to the taste. To smoothen out the taste to where you have very drinkable alcohol, the alcohol is placed in wooden barrels that have been charred. The barrels are stored for a number of years, the more the better, where the alcohol takes on flavor and color from the charred barrels. After aging the alcohol is ready to bottle and consume.

[Click on Picture to Enlarge]

Making Bourbon - Based partly on the recipe for making Maker’s Mark

Whiskey (ethyl alcohol, C2H5OH) is produced by taking starch, corn, and converting the starch into sugar. Next, the sugar is converted into alcohol. The final step is to concentrate alcohol by removing water through distillation. 

Raw Materials:

To be classified as Whiskey one grain has to at least 51% of the grains, to be Bourbon, there has to be at least 51% corn.

Water – best is from a spring where there is a lot of limestone. This water is free of iron and rich in minerals, especially magnesium and calcium. Kentucky and Tennessee has abundant sources of these “sweet waters”.

Malted Barley – barley that has sprouted or germinated

Hops - added to yeast to “sour” it.

Corn – the primary grain in bourbon

Rye or Wheat - one or the other is used, not both

Yeast – a live organism that feeds on fermentable (simple) sugars, such as glucose and fructose.

THE WATER    Get Info

Kentucky spring water, purified as it flows over limestone rock formations, is perfect for bourbon distilling because it is free of minerals that affect taste. This iron-free limestone water is what makes Kentucky bourbon world-renowned. There are few places in the world where there is an abundance of this limestone water; Kentucky and Tennessee are blessed to have so much.


The bourbon recipes consist of a mixture of at least 51 percent corn, with a smaller percentage barley malt and rye or wheat. Each distiller takes great care in selecting the grains, making choices based on quality, ripeness and moisture content. For each type of grain, there are a number of individual varieties just as in wine, there are a number of varieties of grapes.

Each grain is dried and ground into meal. The barley in allowed to germinate and produce a partial flower before it is ground.


Dona Tub -Preparation of yeast mash: A 55 gallon, double walled, stainless-steel Dona tub is used to cook a mixture of water, hops, malted barley and yeast.

  1. Hops and water are added first and brought to a boil. The hops are boiled until saturated, about 25 minutes. The mixture is then allowed to cool to 160 degrees Fahrenheit, about 15 minutes.

  2. Malted barley is next added  and allowed to sit until the grain is saturated, about 1 1/2 hours. The mixture is then cooked until the temperature reaches 178 degrees F and cooked at 178 degrees for another 25 minutes. Then cooled to 80 degrees F.

  3. Yeast is added last and the mixture is allowed to cool to 80 degrees F where it then sits for 24 hours. During this time the yeast ferments.

Yeast Tub - 200 gallon tub:

  1. Grain mash is added to pot

  2. The yeast mash is poured into a larger tub where the volume increases in size by several times.

  3. Mixture is ready in about 3 hours.


The enzymes in the malted barley attack the starch in the mash and slowly break down the starch into a simple sugar.

Mash Tub - 11,000 gallon carbon-steel mash tub (15 ft diameter, 4 ft deep): Three step process.

  1. Water and backset (spent mash after distilling) is added, then heated to 140 degrees F.

  2. Corn is added and the combination is brought to a boil, 212 degrees F. the mash is heated until the corn completely saturated, about 25 minutes.

  3. Mixture is cooled to 156 degrees F.

  4. Wheat or Rye is added.

  5. Mixture cooled to 148 degrees F.

  6. Malted barley is added and the mixture is allowed to cool further to 76 degrees F.

  7. The mash is now mainly dextrose, a simple sugar.


The strains of yeast used in fermenting mash at the various whiskey distilleries is what make one brand of bourbon different from another and are closely guarded secrets in the industry. The yeast is believed to affect the body, aroma and taste of the whiskey as much as the aging process. Many strains have been passed from generation to generation in family-owned distilleries and are still used today.

Fermentation takes place in large tubs, some with a capacity of up to 50,000 gallons. In the early days of bourbon making, tubs made of cypress wood were used to hold the mash. Although some distilleries still use cypress, stainless steel tubs are now common.

After three to four days of fermenting, the mash is converted to alcohol by the yeast until the alcohol concentration approaches 16% by volume. At this point the mash contains so much alcohol that the yeast can no longer consume the remaining sugar and convert it to additional alcohol . During this sugar to alcohol conversion process, Carbon dioxide is given off. At the end of fermentation the resulting beer contains about 14 to 16% alcohol and is now ready to be distilled.

Fermenter - a 10,000 gallon cypress tank:

  1. Mash from the Mash Tub is pumped over to the fermenter

  2. Backset is pumped into the fermenter

  3. Yeast is added

  4. Mixture will ferment for 3 to 4 days. Carbon dioxide is given off during fermentation.

  5. After the fermentation is complete it is pumped to a holding tank where it is heated to 145 degrees F before it is pumped to the still.

Mash - Liquid composed of ground-up grain mixed with boiling water. This extracts soluble starch, which is converted into maltose by the enzyme amylase.  the liquid is drained from the mash tub and fermented into wart.

Mash bill - The grain recipe used to make whiskey

Wart or Beer - the liquid that goes into the still.

SOUR MASH     Get Info

Sour mash is the name for a process in the distilling industry that uses material from an older batch of mash to start fermentation in the batch currently being made, analogous to the making of sourdough bread. The term sour mash can also be used as the name of the type of mash used in that process, and a whiskey made using this process can be referred to as a sour mash whiskey. Sour mash does not refer to the flavor of the whiskey, as is sometimes thought.

The sour mash process was developed by either Dr. James C. Crow or Dr. Jason S. Amburgey while they were working at the Old Oscar Pepper Distillery (now the Woodford Reserve Distillery) in Woodford County, Kentucky.

In the sour mash process, the mash – a mixture of grain, malt and water – is conditioned with some amount of spent mash (previously fermented mash that still contains live yeast). Spent mash is also known as spent beer, distillers' spent grain, stillage, and slop or feed mash, so named because it is used as animal feed. The acid introduced by using the sour mash controls the growth of bacteria that could taint the whiskey and creates a proper pH balance for the yeast to work. An established and active strain of live yeast is introduced into the mash that is to be fermented. By using an established and known fermented "sour", this fermentation process controls the introduction and growth of foreign bacteria and yeasts that could damage the whiskey, and improves the consistency and quality of the liquor, so that every bottle tastes as close to the same as possible. Sour mash is popular in bourbon whiskey and Tennessee whiskey.


The normal type of still used today in the U.S. is the continuous distillation column which is often 60 to 70 feet tall. Older stills and the type used for Scotch are pot stills. However, there is one distillery making bourbon today using the old pot still, that is Labrot & Graham distillery who makes Woodford Reserve. Many stills today are made of copper with some of the newer ones today being made mostly of stainless steel with a small amount of copper. The copper has the effect of removing sulfur compounds from the whiskey.

Still - An apparatus, usually made of copper, in  which the distiller's beer is purified by means of hearing the liquid to at least 176 degrees Fahrenheit, but less than 212 degrees Fahrenheit. Because alcohol boils at a temperature lower than water, the alcohol can be evaporated, collected and condensed and thus separated from the water that makes up part of the mash.

Beer - A general term for all fermented malt beverages flavored with hops. A low level (6 to 12 percent) alcohol solution derived from the fermentation of mash by microorganisms.

Beer Still - The stripping section of a distillation column for concentrating ethanol.

Rectifying Column - The portion of a distillation column above the feed tray in which rising vapor is enriched by interaction with a countercurrent falling stream of condensed vapor.

Stripping Column - The section of the distillation column in which the alcohol concentration in the starting beer solution is decreased. This section is below the beer injection point.

Stripping Section - The section of a distillation column below the feed in which the condensate is progressively decreased in the fraction of more volatile component by stripping.

White Dog - Un-aged distillate, just as it comes from the still, is colorless. Also known as "green whiskey" or "high wine."

Fire Copper - a term used in the late 1800's to describe a “sweet mash” whiskey.

Double Distilled - Most distilleries take the output from the still and pass it through a second still called a “doubler” or through a similar device called a “thumber” to increase the proof of the whiskey.

The distillation process is really simple. All you need is a kettle to boil the mash and a condenser or as they used to call it a worm to cool the vapor as it comes off the kettle. The condenser is a copper coil with cooling water flowing over it to keep it cool. Copper "Kettle" type of still used years ago and is used today at the Woodford Reserve distillery. This type of still is also the type normally of still used for making Scotch Whisky.

In making whiskey with this kettle type of still, often there are three kettles connected together in series. The condensed liquid from the first still goes into the second still which sends its condensed liquid to the third still.

The "column" still is a series of vertical sections that contain trays with bubble caps as shown in the next picture. As the boiling whisky vapors travel up through the trays, it cools a bit and droplets of whiskey and water drop out of the vapor and trickled down through the trays to the bottom of the still. The highly concentrated whiskey is taken off the top of the still where it is cooled. The term "beer column" in the above refers to the introduction of non-distilled whiskey or Beer into the distillation process. The distillation process converts what is actually beer into whiskey by boiling out the whiskey and leaving behind the water.
The whiskey vapor from the boiling mash travels up through the bubble caps. The floor of the bubble tray has condensed liquid which the vapor bubbles through. As the vapor bubbles through the liquid some of the vapor cools and condenses. As the liquid builds up in the tray it will overflow the drain pipe and flow down the column to be reboiled. Modern day "column" still used today in making American whiskies such as Bourbon.

All bourbon and most whiskey stills are either completely made of copper or have some amount of copper inside.

The above photograph is a section of a column still with the side cut away. The internals show the bubble caps that allow the boiling vapors to rise in the still and allow the condensed liquid to flow down the still.  The whiskey still mostly in use today in America consists of one or two distillation columns. The first column takes the beer and converts it to low proof whiskey or "low wines". The second column separates out more water from the whiskey and thus increases the percent alcohol or proof. What comes out of the second column is called "high wines" . 



  1. The fermented mash, beer, is pumped into the still (distillation column) after being heated. In the still the beer mash is heated to between 178 and 196 degrees F. Alcohol boils at 172.9 degrees where as the water boils at 212 degrees. As the mash boils the alcohol turns to vapor and the water and solids are left behind. The vapor is taken off the top of the still and condensed as it passes through cooling coils (worm). Thus the alcohol vapor is turned into liquid alcohol.

  2. Often the alcohol is sent to a second still where its further strengthened by removing more of the water that is carried over from the first still. Some processes use a third still. 

  3. As you increase the proof or percent of alcohol in what comes off the still you loose some amount of flavor. The higher the proof of a bourbon, the lower the amount of flavoring elements it contains. Some makes prefer to distill at high proof but most companies keep the proof well below the limit of 160 proof. Above 160 proof you loose most of the flavor and by law the alcohol cannot be called whiskey or bourbon. The highest proof obtainable is around 195 proof. You cannot get 200 proof because of changes in boiling point of water/alcohol mixtures as the concentration of water drops to far. At very high proofs the alcohol boiling point approaches that of water.

  4. When the still is first started up, the initial proof of the liquid coming off the still is low and the quality is less than desirable. The proof is tested at the Tail Box with a hydrometer and the initial alcohol is recycled back to the still. When the desired proof is reached, the recycle line is closed off and the alcohol is sent to a holding tank.

  5. The holding tank is used to collect the alcohol where water is added to drop the proof to the level desired for storage in barrels. The alcohol proof has to be dropped to at least 125 proof for aging, by law.

  6. There are two methods of increasing the proof as the alcohol comes off the top of the beer still. One method uses a doubler. The alcohol vapors are condensed and sent to a pot still (doubler) where it is boiled again to further separate the alcohol from the water.  Another method used is called a "Thumper". In this method, vapor from the top of the still is sent into a tank of boiling water where it makes a loud thumping sound. As the vapor passes through the water, additional water is removed from the vapors.

BARRELS    Get Info

The new, white oak barrels are filled to capacity with the high wine (alcohol), ready for several years of aging. The barrels are charred on the inside, giving bourbon its amber color and mellow but potent taste. A barrel has a liquid measure equal to 42 American gallons.

Angel's Share - The portion of the whiskey that evaporates from the barrel during the aging process. Typically around 2%, by volume, evaporates per year.

Barrel - A liquid measure equal to 42 American gallons or about 306 pounds; one barrel equals 5.6 cubic feet or .159 cubic meters; for crude oil, one barrel is about .136 metric tons, .134 long tons, and .150 short tons.

Proof – The scale, measured in degrees, used to denote alcohol content; in the United Stated, 200° is equal to 100% alcohol. The term ''proof '' means that liquid which contains one-half its volume of ethyl alcohol of a specific gravity of 0.7939 at 60 degrees Fahrenheit (referring to water at 60 degrees Fahrenheit as unity).

Proof Gallon – One gallon of alcohol at 100° proof.


Aging must take place for a minimum of two years. If aged less than four years, labeling must include age. Most bourbons are aged from four to eight years.

As the liquid ages in the barrel, variations in temperature as the seasons change force it to expand and contract through the caramelized layer of charred wood inside the barrel, "mellowing" it and giving it the distinctive bourbon flavor and appearance.

Most warehouses are built on hilltops or in a staggered format in open fields. They contain several stories of "racks" for housing the barrels and usually allow a certain amount of airflow. Because temperature changes often affect barrels stored on the top story more quickly, some distillers rotate the barrels as they age to even out the process.

Temperature changes cause pure water in the bourbon to evaporate, so the barrels when opened commonly contain much less liquid than when they were filled. Bourbon loses about three percent of its volume for each year of aging, but contains between 10 and 20 percent more alcohol.
Angel's Share - The portion of the whiskey that evaporates from the barrel during the aging process. Typically around 2% to 3%, by volume, evaporates per yea

Because no two barrels of bourbon have been subjected to the exact changes in temperature, variations in alcohol content and character result. Most distillers blend bourbon from the various barrels to ensure a uniform and distinctive final product.

BOTTLING    Get Info

The final step before shipping and selling the whiskey to the consumer.


Originally whiskey was only sold by the barrel. In a tavern the whiskey was transferred to glass decanters and from these decanters the whiskey was poured into glasses. Once the glass bottle became easy and fairly inexpensive to make whiskey was sold by the bottle. They didn't have modern packaging methods so they wrapped the bottle in cardboard.  The wrapped bottle was then placed into a wooden case for storage and shipping.



The left over mash has a lot of food value left over and makes excellent animal feed.

See Whiskey - What's the Difference for a comparison of different brands of whisky.

The recipe listed above came from "the Book of Bourbon and Other Fine American Whiskeys" by Gary Regan & Mardee Haidin Regan, 1995

Grain Water Mash Yeast Fermentation
Distillation Sour Mash Animal Food Barrels Aging