Distillation Glossary

18th Amendment – The 18th amendment of the United States Constitution effectively established the prohibition of alcoholic beverages in the United States by declaring illegal the production, transport and sale of alcohol (though not the consumption or private possession).

21st Amendment – The 21st amendment to the United States Constitution repealed the 18th Amendment to the United States Constitution, which had mandated nationwide Prohibition on alcohol on January 17, 1920.

ABV – Alcohol by volume. The Ethanol content of a spirit expressed as a proportion of its volume.  Read our article on ABV titled “Demystifying ABV Calculation: How to Determine Alcohol by Volume in Your Homebrewed Mash”

Acetaldehyde – A chemical and bi product of fermentation that is perceived as green apples in both aromas and flavor.

Acetone – A colorless, volatile, flammable, and pungent substance released at the start of distillation.

Acid Rest – A step done early in the mash around 95F by traditional brewers to lower the pH of the mash.

Acrospire – The shoot that grows as a barley grain is germinated.

Adjunct – Any unmalted grain or other fermentable ingredient used in the brewing process. Adjuncts used are typically either rice or corn, and can also include honey, syrups, and numerous other sources of fermentable carbohydrates. They are common in mass produced light American lager-style beers.

Aeration – The action of introducing air or oxygen to the wort (unfermented beer) at various stages of the brewing process. Proper aeration before primary fermentation is vital to yeast health and vigorous fermentation. Aeration after fermentation is complete can result in beer off-flavors, including cardboard or paper aromas due to oxidation.

Aging – Distilled spirit is stored in wooden barrels (usually Oak) to enhance the flavor.

Air lock – A valve often used in fermentation.

Alcohol – A synonym for ethyl alcohol or ethanol, the colorless primary alcohol constituent of beer. Alcohol ranges for beer vary from less than 3.2% to greater than 14% ABV. However, the majority of craft beer styles average around 5.9% ABV.

Alcohol by Volume (ABV) – A measurement of the alcohol content of a solution in terms of the percentage volume of alcohol per volume of beer. This measurement is always higher than Alcohol by Weight. To calculate the approximate volumetric alcohol content, subtract the final gravity from the original gravity and divide by 0.0075. For example: 1.050 – 1.012 = 0.038/0.0075 = 5% ABV.
Alcohol by Weight (ABW) – A measurement of the alcohol content of a solution in terms of the percentage weight of alcohol per volume of beer. For example: 3.2 percent alcohol by weight equals 3.2 grams of alcohol per 100 centiliters of beer. This measure is always lower than Alcohol by Volume. To calculate the approximate alcohol content by weight, subtract the final gravity from the original gravity and divide by 0.0095. For example: 1.050 – 1.012 = 0.038/0.0095 = 4% ABW.
Alcoholic

• Warming taste of ethanol and higher alcohols. Can be described as spicy and vinous in character. The higher the ABV of a beer, often the larger the mouthfeel it has. Alcohol can be perceived in aroma, flavor and as a sensation.
• A person with a disabling disorder characterized by compulsive uncontrolled consumption of alcoholic beverages.

Alembic – A type of copper still design

Amylase – An enzyme that breaks down starch into fermentable sugars

Azeotrope – A mixture of two or more liquids that boils  at a constant temperature and composition, meaning the vapor has the  same composition as the liquid mixture. Azeotropes can make separation  by simple distillation difficult.

Backings – Also singlings and low-wines – what results after beer is run through a thumperless operation once. They have a good percentage of alcohol, but they won’t hold a bead.

Backins or Back-ins – See Backings

Backset – What is left in your still after distillation. Referred to as” Dunder” when Rum has been distilled.

Bale – wire or chain strapped across top of cap to keep it from blowing off during the cooking process.

Barrel/Cask-Aging – Aging  the product of distillation in a wooden (often oak) barrel or cask that  may or may not have been previously used to age another spirit and may  or may not have been charred to blacken the inside. The aging process  mellows some of the harshness of the spirit while also infusing it with  both color and character from the wood itself.

Batch Distillation – Distillation performed in discrete batches, where a certain amount of mixture is processed at a time.

Beer – the fermented liquid made from corn meal bases which, when cooked in the still, produces the moonshine.

Blending – The art of putting together the different collection cuts to achieve the best final product as possible.

Blockaders – Men who made moonshine. The name is a holdover from the days in our history when blockades were common, as were blockade runners. Also gave rise to the expression “blockade whiskey.”

Blubber – The bubbles which result when moonshine in the proof vial is shaken violently.

Boiler – The body of the still.

Boiling Flask (Pot Still) – The container in which the liquid mixture to be distilled is heated. In simple distillation, this is the only vessel used.

Boiling Chips – Small porous stones used to create an even, smooth boil in heated liquids.

Boiling Point – The temperature at which a substance changes from a liquid to a vapor (gas) at a given pressure.

Bootlegger – Someone who sells moonshine or legal spirit under illegal circumstances.

Breaks at the worm – An expression used at the moment when the whiskey coming out of the flake stand turns less than 100 proof, and thus will no longer hold a bead.

Brix Scale – a measurement used in brewing and other industries to determine the sugar content in a liquid solution.  Read our article about the brix scale titled “Unlocking the Secrets of the Brix Scale: A Guide to Measuring and Mastering Sugar Content in Brewing”

Busthead and popskull – Names applied to whiskey which produces violent headaches due to various elements which have not been removed during the stilling process.

Cap (2 meanings) – The top third of the still. It is removable so that the still can be filled after a run.  Or, the foamy krauesen that forms on the top of a fermenting liquid.

Cap Arm – The copper pipe connecting the cap with the next section of the still; it conveys steam to this section.

Cape – the bulge in the main body of the still. It is the point of greatest circumference.

Collar – the connection for the cap and the body of the still.

Condensation – The process by which a gas or vapor changes to a liquid.

Condenser – A device used to cool and condense vapor back into liquid. It is an essential component of a distillation setup. Worm, Dephlegmator, Liebig and Shotgun are all examples.

Congeners – These  are substances other than ethanol (see later) which are produced during  fermentation. Their presence contributes to the flavor of the end  product (positively and negatively)

Continuous Distillation – A process where a constant  feed of mixture is introduced while the products are continuously  withdrawn. Common in industrial applications.

Conversion – Enzyme conversion of starches to fermentable sugars. Also, can be called saccharification.

Cuts – The  four stages of the distillation run. (See foreshots, heads, hearts, and  tails). Collection in small containers to identify the changes from  Heads, Hearts, and Tails before blending.

Dead Devils – Tiny beads in the proof vial which indicate that the whiskey has been proofed sufficiently. Stop adding water or backings at the moment shaking the proof vial produces dead devils.

Degrees Lintner – A  unit used to measure the ability of a malt to reduce starch to sugar,  that is, its diastatic power. While the measurement is applicable to any  amylase, in general it refers to the combined α-amylase and β-amylase  used in brewing.

Dephlegmator – A reflux condenser able to condense all vapors and partially condenser column vapors. Used mainly in plated columns.  Read our blog article on the dephlegmator titled “Understanding the Dephlegmator: Enhancing Distillation Efficiency”

Diastatic Power (DP) – An indicator of the total enzymatic strength available to convert starches into fermentable sugars.

Distillate – The condensed vapor collected after the distillation process, containing the separated components.

Distillation – A separation process used to separate components of a liquid mixture  based on their differing boiling points. The mixture is heated to  vaporize the more volatile components and then condensed back into  liquid form.

Distillation Column – A tall vertical tower or column  used in fractional distillation. It contains a series of trays or  packing material that provide surfaces for vaporization, condensation,  and separation of components.

Dog Heads – when the beer is almost ready to run, it will boil up of its own accord in huge, convulsive bubbles which follow each other one at a time.

Doubled and Twisted – in the old stills, all the singlings were saved and then run through at the same time thus doubling their strength. Whiskey made in this fashion was called doubled and twisted.

Doubler/Thumper – An  airtight container that can be placed between the boiler and the  condenser of a pot still to increase the proof of a single run.

Ethanol – The  specific type of alcohol consumed in alcoholic beverages. A clear,  colorless, flammable oxygenated hydrocarbon. Chemical formula: C2H5OH.  It has a boiling point of 78.5°C in the anhydrous state. However, it  forms a binary azeotrope with water, with a boiling point of 78.15°C at a  composition of 95.57 percent by weight ethanol.

Eutectic Mixture – A mixture of substances that melts or  solidifies at a lower temperature than any of its individual  components. This phenomenon can impact separation during distillation.

Faints or Feints – Dead beer; or backings that steam has been run through in a thumper to strengthen a run. These are drained and replaced before each new run.Technically  tails only. Often used to refer to a mixture of heads and tails to be  recycled into a following batch. Feints are low in alcohol and are  re-distilled.

Fermentation – The anaerobic conversion of sugar to carbon dioxide and alcohol by yeast.

Fermenter – The  vessel in which the process of mash fermentation takes place. This is  what contains all the ingredients of the mash during the fermentation  process.

Filter – A device or technique used to remove unwanted particulates or congeners.

Final Gravity – Final Gravity (FG) is the final reading with the brewing hydrometer when fermentation is completed.

Flake Stand – The container through which water is constantly flowing for final condensation of the steam. Holds the worm, condenser, or radiator, depending on which apparatus is being used.

Flavoring – Intentional addition of extracts or fruit essences.

Foreshots – The first cut of liquid to emerge from the still.

Fractional Distillation – A type of distillation that  involves using a fractionating column or distillation column to achieve  multiple vaporization-condensation cycles within a single distillation  process. This is particularly useful for separating components with  closer boiling points.

Funnel – Usually holds whatever material you are using to strain the whiskey. Whiskey passes through it and into the jug or jar.

Furnace – Stone structure in which the still sits for heating.

Fusel oil – Bitter, oily liquid known as congeners composed of generally undesirable substances.

Goose Eye – A good bead that holds a long time in the vial.

Grain Bill – Types and ratios of grains used in a whiskey recipe.

Headache Stick – the long thump rod.

Heads – The second cut of distillate

Hearts – The third cut, and the sweet spot of the distillate.  The desired product, typically collected in the middle of the distillation.

Heater Box (or pre-heater) – A device which heats the fresh beer which will be used in the next run.

High Shots – Untempered, unproofed whiskey. At times it is nearly as strong as 200 proof.

Hydrometer – Used  to measure a solution in water. Home distillers use two specific types  of hydrometers. In the brewing process, a saccharometer is used to  measure the solution of sugar in water. In distilling, an Alcoholmeter  is used to measure a solution of alcohol in water.  Read our article on the saccharometer titled “Mastering the Triple-Scale Hydrometer: Your Complete Guide to Precision Brewing”

Infusion – The  process of infusing a finished spirit with an added flavor, usually by  putting the desired ingredient (fruit, vegetable, spice) directly into  the spirit and letting it steep for a specific period of time.

Krauesen – Layer of foam that forms on the top of a mash/wash during fermentation.

Long Thump Rod – An open-ended copper pipe which conveys the steam into the bottom of the thump barrel where it is released.

Low Wines – A low ABV liquid produced from a stripping run.

Malt – Germinated,  sprouted, dried and ground grain. Malting initiates the process by  which enzymes are produced that will convert the long chain starches  into fermentable sugars. When the sprouts are dried this process is  interrupted and suspended until the malted grains are rehydrated at  specific temperatures to activate the enzymes in the mash process.

Mash – A mixture of ground grains, malt, water, and yeast. Can also be used to describe fruit-based mixes.

Mash Stick – The stick used to break up the cap that forms over the mash and stir up the contents of the barrel. Sometimes it is made of a stick which has a crook in the end. Several holes are drilled in this crook, and pegs are inserted to form a comb-like device. It can also be a stick with several nails driven in the side.

Mashing – The art of cooking grain and converting starches to fermentable sugars.

Mash Tun – A large vessel able to withstand high temperature used to mix a mash or a wash and can serve double duty as a fermenter.

Moonshine – Illicitly produced, distilled spirits on which no tax is paid.  Various names given moonshine include ruckus juice (pronounced “rookus”), conversation fluid, corn squeezin’s, corn, white, white lightenin’, cove juice, thump whiskey, headache whiskey, blockade whiskey, etc.

Oaking – Adding color and character in glass with oak chunks, staves, or chips.

Original Gravity – The  original gravity (OG) is the first reading taken with the brewing  hydrometer to measure the specific gravity of a wash before fermentation  has started. Also known as initial gravity or starting gravity

Parrot – A device connected after the condenser arm containing the alcoholmeter, which allows real time readings of alcohol level.

Peated – A  term you might see on a Scotch whisky bottle, indicating the malted  barley has been dried over a peat fire and the finished product will  have a distinctive smokiness.

Plug Stick – a hickory or white oak stick with a bundle of rags fastened to one end. The rags jam into the slop arm thus sealing the bottom of the still.

Poitín – Illicit, untaxed Irish moonshine.

Pot still – A  traditional still generally used for the making of whiskey and brandy.  Often made from copper and designed for quick passage of vapor with  minimal reflux.  Read our article about the pot still titled “From Ancient Origins to Timeless Craft: Unveiling the Rich History and Art of Pot Stills in Liquor Distillation”

Pot-Tail – see Slop.

PPG – PPG  stands for Points per Pound per Gallon. PPG is used as a measure of the  available gravity points in a grain, sugar, or recipe.  Read our article about PPG titled “Gravity Points 101: The Importance of PPG in Brewing History and Practice”

Proof – The proportion of alcohol in distilled spirit.  See Temper for an alternate meaning.

Proof Vial – A glass tube used to check the bead of the whiskey. A Bateman Drop bottle was the most popular as it held exactly one ounce, and was just the right shape. Others used now are bottles that rye flavoring comes in, or a government gauge.

Racking – The process of transferring mash/wash from one container to another.

Rectification – The process of purifying or refining a liquid mixture by repetitive distillation or fractionation.

Reflux – The process of returning condensed vapor back  to the distillation column. It helps maintain temperature and aids in  efficient separation, especially in fractional distillation.

Reflux still – This  still uses a distillation column which facilitates greater separation  of the mash, and results in a refined and higher proof distillate.

Relay Arm – The pipe connection from the bottom of the relay barrel back into the still.

Relay Barrel or Dry Barrel – A fifty-gallon barrel with connections for the cap arm, relay arm, and a long thump rod. Catches “puke” from the still during boiling and conveys it back into the still.

Rig – A distillation set up

Run or A Run – A distillation cycle.  An expression meaning to run the contents of the still through the whole operation once. It gave rise to expressions like, “There’s gonna be a runnin’ tomorrow,” “He’ll make us a run,” etc.

Sediment – The settling of suspended particles to the bottom of the fermenter.

Singlings – See Backings.

Slop – That which is left in the still after the whiskey will no longer hold a bead at the end of the worm. It is too weak to produce and so it is dumped at once. Left in the still, it will burn. Some people use it for hog feed, others in mash.

Sour Mash – Mash made with pot-tail.

Sparge – Removing fermentable liquid from grain after starch conversion in order to strain off as many sugars as possible.

Specific Gravity – In brewing, Specific Gravity (SG) is used to measure the sugar in solution compared to just water.  Read our article titled “Brewing 101: Understanding the Magic of Specific Gravity”

Spirit Run – The last and final run of a multiple run process. Ran slow to get the best product.

Steam Distillation – A method used to distill heat-sensitive compounds or components with high boiling points by introducing steam into the mixture.

Still – The container into which the beer is placed for boiling. Also called the Evaporator, Boiler, Kettle, or Cooker. The name can also refer to the entire operation from the evaporator through the flake stand.  Read our article on the different types of liquor stills titled “Exploring the Art of Distillation: A Guide to the Different Types of Liquor Stills”

Stripping Run – The  first runs of a multiple run process. Where the alcohol is stripped out  of the fermented beer. To increase ABV and clean it up more. Producing  what is called low wines. In preparation for a spirit run.

Swab Stick or Toothbrush – A hickory stick half as thick as your arm and long enough to reach from the top to the bottom of the still. One end is beaten up well so that it frazzles and makes a fibrous swab. This is used to stir the beer in the still while waiting for it to come to a boil, thus preventing it from sticking to the sides of the still, or settling to the bottom and burning. If the latter happens, the whiskey will have a scorched taste.

Sweet Mash – Mash that has been made with pure water. The first run through the still is made with sweet mash.

Split Brandy – A mixture that is half whiskey, half brandy. It is made by mixing mash that is one-quarter fruit content. Then proceed as usual with the beer-making, and running.

Temper – The process of adding water or backings to the whiskey to reduce its strength to about 100 proof.

Thump Barrel – Also Thumper or Thump-Post—a barrel which holds fresh beer, and through which steam from the still bubbles thus doubling its strength. The strengthened steam moves from here into the short thump rod which carries it either into the heater box, or into the flake stand.

TPW – Tomato paste wash

Tails – The last part of the distillate. This phase of the distillation run has high volumes of congeners and oils.

UJSSM – Uncle Jesse’s Simple Sour mash.

Vacuum Distillation – Distillation performed at reduced  pressure (lower than atmospheric pressure), which lowers the boiling  points of components and helps prevent decomposition of heat-sensitive  materials.

Vapor Pressure – The pressure exerted by a vapor in equilibrium with its liquid phase at a certain temperature.

Wash – A liquid mixture containing sugar and yeast.

Worm – The condenser associated with a traditional pot still and thumper.  Often a copper tube, usually sixteen to twenty feet long which is coiled up so that it stands about two feet high and fits inside a barrel. Water flows around it for condensing the steam which passes into it from the still.

Wort – The solution of grain or fruit sugars strained from the mash tun

Yeast – A  sugar eating fungus used in fermentation. Any of certain unicellular  fungi, generally members of the class Ascomycetaceae, (although a few  are members of the class Basidiomycetaceae). Many types of yeast are  capable of producing ethanol and carbon dioxide by the anaerobic  fermentation of sugars. Yeasts are composed of approximately 50 per cent  protein and are a rich nutritional source of B vitamins