Distilleries Industry Terminology

ABV (Alcohol by Volume)

The percentage of ethanol by volume in a liquid at a standard temperature (commonly 20°C). It is the primary strength measurement for spirits globally.

- The new make comes off at 70% ABV before dilution. - Label this gin at 45% ABV. - We’ll increase the entry ABV slightly to improve extraction.

Aging/Maturation

The time-dependent transformation of spirit in contact with wood and oxygen, producing color and complex flavors via extraction, oxidation, esterification, and other reactions.

- Scotch requires a minimum maturation of three years in oak. - Hot summers accelerate maturation in our rickhouses. - We’re comparing maturation outcomes between warehouse A and B.

Angel's Share

The portion of spirit lost to evaporation through the barrel during maturation.

- Our angel’s share averages 2–4% per year. - Tropical aging increases the angel’s share significantly. - Humidity control can reduce the angel’s share of alcohol relative to water.

Barrel Proof (Cask Strength)

Spirit bottled at the strength at which it leaves the cask, without or with minimal dilution.

- We released a barrel-proof bourbon at 62.3% ABV. - Cask strength lots often skip chill filtration. - Calculate tax based on the lot’s proof gallons at barrel proof.

Batch Distillation

A non-continuous distillation method where discrete charges of wash are distilled in runs, typically using pot stills.

- Our pot still handles 1,500 L batch distillations. - We adjust cuts each batch to maintain the house style. - Batch-to-batch variation is balanced through blending.

Blending

Combining multiple spirits (different casks, ages, distillates, or components) to achieve a desired and consistent flavor profile.

- Blend high-ester and light rums to hit the target profile. - The master blender uses 12 cask types in the final cuvée. - Blending smooths batch variation before bottling.

Botanicals

Plant materials (e.g., herbs, spices, peels, roots) used to flavor spirits such as gin, aquavit, and some liqueurs via maceration, percolation, or vapor infusion.

- Juniper, coriander, and angelica are the core botanicals. - We’re trialing fresh citrus as a botanical in the gin basket. - Always verify botanical allergen status for HACCP.

Bourbon

A U.S. whiskey defined by regulations: at least 51% corn in the mash bill, distilled to ≤80% ABV, entered into new charred oak barrels at ≤62.5% ABV, and bottled at ≥40% ABV.

- The mash bill at 70% corn meets the bourbon standard. - Bourbon must enter new charred oak at ≤125 proof. - Used barrels disqualify the whiskey from being called bourbon.

Cask Finish

Secondary maturation in a different cask type (e.g., sherry, port, rum) to add layers of flavor after primary aging.

- A 12-month sherry cask finish adds dried-fruit notes. - We’re finishing the rye in port pipes. - The finish program diversifies our portfolio.

Char Level

The degree to which a barrel’s interior is carbonized by flame; impacts extraction, flavor development, and filtration in maturation.

- Standard bourbon barrels are char #3. - We ordered char #4 for deeper caramel and smoke. - Specify toast and char levels to the cooperage.

Chill Filtration

A process of cooling spirit and filtering out fatty acids and other compounds to improve clarity and stability, sometimes at the expense of texture and flavor.

- This release is non-chill filtered to preserve mouthfeel. - We chill filter at -2°C with 5-micron pads. - Chill haze is reduced by chill filtration but may strip flavor.

CIP (Clean-in-Place)

Automated cleaning of tanks, lines, and equipment by circulating detergents and sanitizers without disassembly, ensuring hygiene and product safety.

- Run a caustic CIP on the beer column before the next mash. - We validated our CIP cycle as a HACCP critical control point. - The CIP skid logs concentration, temperature, and time.

Column Still

A continuous distillation apparatus (e.g., Coffey, multi-plate columns) that separates components using trays or packing and controlled reflux.

- Our 20-plate rectifier yields 95% ABV GNS. - Increase reflux on the column to purify the spirit. - Columns enable continuous distillation at scale.

Congeners

Flavor-active compounds (e.g., esters, aldehydes, higher alcohols) formed mainly during fermentation and modified by distillation and aging.

- We’re targeting fruity ester congeners in the rum. - Heads carry volatile congeners like acetaldehyde we want to minimize. - Congener profile drives the new make’s character.

Cooperage

The craft and business of making and supplying wooden barrels; also the facility or company that produces them.

- We contracted a Missouri cooperage for American oak. - Lead times at the cooperage affect our fill schedule. - The cooperage will toast before charring to our spec.

Dilution/Proofing

The controlled addition of water to adjust spirit strength to target bottling proof; must account for temperature and measurement accuracy.

- Proof down gradually to reduce saponification risk. - Use temperature-corrected tables when proofing. - We proof with RO water for consistency.

Distillation

Separation of components by boiling and condensation, exploiting differences in volatility to concentrate ethanol and desirable congeners.

- The spirit run refines the low wines. - Distillation rate influences reflux and copper contact. - We set cut points based on sensory and ABV readings.

Distillation Proof

The alcoholic strength of spirit as it leaves the still, often regulated by spirit category and used for compliance and record-keeping.

- Bourbon must be distilled under 160 proof. - Record distillation proof in the daily logs. - Higher distillation proof yields lighter flavor.

Dunder

Residue from rum distillation used to acidify and flavor future fermentations; similar to backset in whiskey.

- Add 10% dunder to the fermenter for Jamaican-style rum. - Dunder pit microbes boost ester formation. - Monitor dunder acidity as part of the recipe.

Enzymes (Amylase)

Biocatalysts used to convert starches to fermentable sugars; alpha-amylase breaks chains, glucoamylase releases glucose.

- Dose alpha-amylase during the cook for liquefaction. - Glucoamylase completes saccharification before fermentation. - Enzyme activity is verified with iodine tests.

Esterification

A reaction between acids and alcohols forming esters, key contributors to fruity and floral aromas in spirits.

- Long ferments encourage esterification and fruit notes. - Oak casks facilitate slow esterification over time. - We target ethyl acetate and ethyl butyrate levels.

Fermentation

Yeast-driven conversion of sugars into ethanol, CO2, and flavor compounds; the foundation of spirit character.

- Fermentation finishes in 72 hours at 30°C. - The yeast strain and nutrients control fermentation kinetics. - pH drop confirms a healthy fermentation.

Foreshots

The very first fraction to come off a still, rich in highly volatile, undesirable components; removed for quality and safety.

- Discard foreshots before collecting heads and hearts. - Methanol and ultra-volatile compounds concentrate in foreshots. - Tight management avoids smearing foreshots into hearts.

Fusel Alcohols

Higher alcohols (e.g., propanol, butanol, amyl alcohols) formed during fermentation; affect aroma, mouthfeel, and potential haze.

- Lower the ferment temperature to reduce fusels. - Excess fusel oils can cause harshness and haze. - Manage fusels via cuts and fermentation health.

Geographical Indication (GI)

A legal designation linking a product’s qualities and reputation to its geographic origin and specified production methods.

- Scotch Whisky GI dictates production and labeling rules. - Tequila’s GI limits production to specific regions. - Verify GI claims before export labeling.

GNS (Grain Neutral Spirit)

A highly rectified ethanol, typically ≥95% ABV, often used as a base for vodka, gin, and liqueurs.

- We buy GNS and redistill for our vodka. - Dilute GNS to 40% ABV before carbon polishing. - GNS purity is ≥95% ABV by definition.

Grist

Milled grain intended for mashing; particle size distribution influences extraction and mash flow.

- Adjust mill gap to optimize grist particle size. - Grist composition affects conversion and lautering. - Check grist moisture before mashing.

HACCP

Hazard Analysis and Critical Control Points: a systematic preventive approach to food safety and regulatory compliance.

- Our HACCP plan lists botanicals as an allergen hazard. - CIP verification is a HACCP critical control point. - Auditors reviewed our HACCP records last week.

Heads

The early fraction following foreshots; contains lighter volatiles that are reduced or recycled to improve spirit quality.

- Extend the heads cut to reduce solvent notes. - We recycle heads into the next low wines charge. - Heads contain acetaldehyde and ethyl acetate.

Hearts

The desired middle cut of a distillation run, retained for maturation or bottling due to its clean and balanced profile.

- Collect hearts between about 73–65% ABV. - Only hearts make the final single-barrel release. - Sensory checks confirm the hearts window.

Hydrometer

A device that measures specific gravity; alcohol hydrometers (alcoholmeters) are used to determine proof or ABV in distillates.

- Use an alcohol hydrometer with temperature correction. - Verify ferment attenuation with a SG hydrometer. - Calibrate hydrometers annually to maintain accuracy.

In-Bond

Status of spirits stored under excise control without tax payment, typically in licensed bonded premises.

- Transfer barrels in-bond to our secondary warehouse. - Keep accurate in-bond records for TTB audits. - Aging in-bond defers excise tax liability.

Infusion

Extraction method where botanicals or other ingredients are steeped in spirit or wash to transfer flavor compounds.

- Cold infusion of citrus peels in neutral spirit for 24 hours. - Compare vapor infusion to maceration for juniper extraction. - Post-infusion filtration clarifies the liqueur.

Low Wines

The intermediate distillate from the first run of a double distillation process, destined for further distillation.

- The wash still yields low wines at around 25% ABV. - Charge the spirit still with low wines and feints. - Blend low wines from multiple batches for consistency.

Lyne Arm

The pipe leading from the pot still to the condenser; its length and angle influence reflux and spirit character.

- An upward-sloping lyne arm increases reflux and lightness. - We’re modifying the lyne arm angle to tweak style. - Copper contact in the lyne arm helps reduce sulfur.

Malt

Germinated and kiln-dried grain (often barley) providing enzymes and flavor precursors for mashing and fermentation.

- Peated malt contributes smoke phenols. - Check malt DP and moisture on arrival. - We source malt from a local maltster.

Mash Bill

The specific proportions of grains used in a whiskey’s recipe.

- A 70/15/15 corn-rye-malted barley mash bill. - Higher rye in the mash bill boosts spice notes. - Document the mash bill for labeling compliance.

Mash Tun

A vessel where milled grain and hot water are combined to convert starches into fermentable sugars.

- Hold saccharification rest at 64°C in the mash tun. - Rakes and screens improve mash tun efficiency. - CIP the mash tun after each cook.

Methanol

A toxic alcohol present in small amounts in distillates, concentrated in early fractions; managed via cuts and compliance testing.

- Ensure methanol stays within legal limits. - A conservative heads cut helps control methanol. - Report methanol in the certificate of analysis.

NAS (No Age Statement)

A product label that omits the declared age, allowing a blend of different ages within legal norms.

- NAS releases allow greater blending flexibility. - Different markets have specific NAS labeling rules. - NAS strategy supports limited cask availability.

New Make Spirit

Freshly distilled spirit prior to any maturation in wood.

- New make at 70% ABV shows a malty, fruity profile. - New make quality predicts cask selection. - We test new make for congener and sulfur levels.

Oak Species

The type of oak used for barrels; species influence grain, extractives, oxygen ingress, and resulting flavor.

- American oak (Quercus alba) vs European oak (Q. robur). - Mizunara oak adds incense and sandalwood notes. - Specify species on cooperage purchase orders.

Oxidation

Reactions with oxygen that modify color and flavor, occurring during barrel aging and handling.

- Micro-oxidation through staves softens tannins. - Excess headspace accelerates oxidation. - Limit oxidation by inerting tanks during transfer.

pH

A measure of acidity/alkalinity; critical for mashing efficiency, yeast health, and product stability.

- Adjust mash pH to 5.4 for optimal enzymes. - A falling pH indicates healthy fermentation. - Keep proofing water pH consistent for stability.

Phenols

A class of aromatic compounds that can deliver smoky, spicy, or medicinal notes; key in peated whiskies and barrel-derived flavors.

- Peated malt contributes 25 ppm phenols. - Manage phenolic carryover via copper contact and cuts. - Phenols integrate over long maturation.

Pot Still

A batch distillation vessel, typically copper, used for producing characterful spirits through discrete runs and cut management.

- Copper pot stills help remove sulfur compounds. - Our spirit still is charged to 80% capacity. - Double pot distillation shapes a richer profile.

Proof

In the U.S., a measure of strength equal to twice the ABV (e.g., 50% ABV = 100 proof); used for labeling and taxation.

- Bottled at 100 proof (50% ABV). - Use TTB proof tables at 60°F for corrections. - Price tiers increase with proof in some markets.

Proof Gallon

A U.S. tax unit equal to one gallon of spirit at 50% ABV at 60°F; used for excise calculations and record-keeping.

- We removed 500 proof gallons this month. - TTB monthly reports require proof gallon totals. - Convert bulk receipts to proof gallons for inventory.

Rickhouse

A barrel warehouse for aging spirits; construction, location, and microclimate influence maturation outcomes.

- Top-floor rickhouse barrels mature faster. - We rotate barrels across the rickhouse annually. - Rickhouse design impacts airflow and temperature swings.

TTB (Alcohol and Tobacco Tax and Trade Bureau)

The U.S. federal agency regulating distilled spirits permits, labeling, excise taxes, and reporting.

- Submit the label for COLA approval to TTB. - Maintain the DSP permit and update TTB on changes. - File monthly TTB forms with proof gallon totals.