Gin Distillation & Production – Art Meets Science

Gin is one of the few spirits where the artistry of production is as much about restraint as it is about innovation. Unlike whisky or rum, which rely heavily on fermentation and maturation, gin’s defining character emerges primarily during distillation. Every decision, from the purity of the neutral spirit to the way botanicals are extracted and cuts are managed, determines the balance of flavour in the final glass.

Gin distillation is one of the most technically precise operations in spirits. Where whisky distillers can lean on cask influence, gin distillers must capture perfect balance in a single run. That requires intimate knowledge of chemical volatility, botanical solubility, and sensory cut management.

For me, the most exciting development is the integration of sensory and chemical benchmarking. Distillers can now measure α-pinene levels in juniper or linalool in coriander and map how their gins compare to benchmarks like Gordon’s or Tanqueray. This blend of artistry and analytical science is pushing gin into a new era of precision.

The Base: Neutral Spirit

The canvas for gin is a highly rectified neutral spirit, typically distilled to 96% ABV or higher to strip out congeners and allow botanicals to shine.

• Grain-based spirit (wheat, barley, rye): common in London Dry gins. Clean and crisp.

• Grape-based spirit: G’Vine uses Ugni Blanc grapes, giving a softer, rounder base.

• Potato-based spirit: Chase creates gins with a weightier mouthfeel.

• Molasses-based spirit is economical, neutral and used by several large-scale distillers.

The choice of base spirit subtly affects texture and sweetness, though in premium gins the neutral spirit is usually so clean that botanicals dominate.

Extracting Botanical Flavours

Botanical extraction is where science and artistry converge. Distillers must coax flavour compounds from seeds, roots, peels, and herbs in a way that preserves balance.

Maceration

Botanicals are steeped in diluted neutral spirit (often around 45–50% ABV) for several hours to overnight. The infused liquid is then distilled.

• Strengths: Robust extraction of heavier compounds like α-pinene (juniper), coumarins (angelica), and lactones.

• Drawbacks: Can lead to heavy, resinous gins if not balanced.

Classic example: Tanqueray London Dry relies heavily on maceration for its bold juniper punch.

Vapour Infusion

Delicate botanicals are placed in baskets above the liquid in the still. Alcohol vapours pass through, extracting lighter volatile oils.

• Strengths: Preserves bright citrus terpenes and floral compounds.

• Drawbacks: Less intense; requires careful calibration.

Bombay Sapphire exclusively uses vapour infusion via historic Carterhead stills.

Split Charging / Hybrid Methods

Many modern gins combine both: macerating roots and seeds, while vapor-infusing delicate peels or flowers. Tanqueray No. 10 distills fresh citrus fruit separately in small stills, combining robustness with brightness.

Cut Management: Timing is Everything

During distillation, flavours emerge in sequence as volatile compounds evaporate at different points:

• Early (heads): Bright citrus (limonene, citral).

• Heart: Juniper (α-pinene, sabinene), coriander (linalool), spice balance.

• Late (tails): Earthy roots (angelica, licorice) and heavier oils.

If a distiller cuts too early, the gin may lack juniper structure; too late, and it risks bitterness or solvent-like notes. Analytical tools like GC-MS (Gas Chromatography-Mass Spectrometry) now allow producers to map exact concentrations of volatiles, benchmarking their cuts against competitors. This is the new frontier of gin-making science.

Dilution and Stability

After distillation, gin is typically collected at 70–80% ABV before being diluted to bottling strength with ultra-pure water, usually demineralised or carbon-filtered since minerals can react with citrus oils and cause haze, known as the “louche” effect. London Dry must be at least 37.5% ABV in the EU and UK, though it is often bottled between 41–47%, while Navy Strength sits at a traditional 57% ABV, historically strong enough to ignite gunpowder and still valued for its intensity. Old Tom and other flavoured gins generally fall slightly lower, with sweeteners or infusions added to create softer or more expressive profiles.

Technical Challenges

• Botanical Variability: Coriander from Morocco vs. Bulgaria shows dramatically different oil content. Distillers must adjust recipes accordingly.

• ABV Effects: Higher charge strength emphasises dryness and juniper; lower charge strengths emphasise citrus and floral oils.

• Batch Consistency: Industrial producers like Diageo rely on strict sensory panels and GC-MS data to ensure Tanqueray distilled in Scotland tastes the same as Tanqueray distilled in the US.

• Innovation vs. Regulation: While creative botanicals are encouraged, distillers must ensure juniper dominance to retain legal gin status.

Distillation in Practice

• Tanqueray: Maceration-led, high juniper load (~70% botanical bill), bold, piney profile.

• Bombay Sapphire: Carterhead stills with vapour infusion; light, floral, delicate balance.

• Beefeater: Classic steeping method, 24-hour maceration before distillation; balanced juniper and citrus.

• Hendrick’s: Distills in both Bennett (maceration-heavy) and Carterhead stills, blending robustness with delicacy; adds cucumber and rose essences post-distillation.

• Four Pillars: Uses German Holstein stills; macerates classic botanicals, then vapour-infuses Australian natives like lemon myrtle for freshness.

Gin production is a marriage of tradition and science. Neutral spirit provides a clean canvas; distillation techniques decide how botanicals are expressed; cut management sculpts the flavour arc; dilution and stability polish the final spirit. Whether bold like Tanqueray, delicate like Bombay Sapphire, or terroir-driven like Four Pillars, every gin tells the story of these technical decisions.