For alcohol in glass, the closure follows the drink: screw caps for vodka, gin and most mainstream spirits, cork for still wine and spirits sold on a premium image, crown caps for beer, hard seltzer and ready-to-drink (RTD) mixes. Whichever you choose, the cap has to match the neck finish of the bottle, and in most markets it needs some form of tamper evidence. The sections below compare the options and then cover fit, tamper evidence and recyclability.
Closure types compared
| Closure | Typical use | Strengths | Limits |
|---|---|---|---|
| Screw cap (continuous thread) | Vodka, whiskey, rum, gin, tequila | Low cost, resealable, runs on almost any automated filling line | Cap thread and neck finish must match precisely |
| Natural cork | Still wine, some aged spirits | Lets in a very small amount of oxygen, which supports bottle ageing | Cork taint (TCA) affects roughly 1-3% of bottles |
| Agglomerated or composite cork | Wine and spirits wanting a cork look | More uniform than natural cork and less prone to taint | Not the same material story as a one-piece natural cork |
| Synthetic cork | Spirits, RTD formats | No TCA, lower cost, still gives a pull-out opening | Not suited to wines intended for ageing |
| Crown cap | Beer, hard seltzer, pre-mixed cocktails | Strong oxygen barrier, very cheap, fast to apply | Tighter neck tolerance than a screw finish |
| Pour spout | Bars and restaurants | Fast, consistent pouring | A dispensing fitment, not a shelf seal |
Screw caps for mainstream spirits
Most spirits on a mainstream shelf carry a screw cap, known in the trade as a continuous thread closure. Aluminium is the usual shell material. It is light, resists corrosion, and takes embossing, colour coatings and a tamper band without difficulty.
Inside the shell sits a liner, normally polypropylene (PP) or polyethylene (PE), which acts as the oxygen barrier and keeps the spirit stable for years. A few high-end brands use metal-to-metal screw closures with no liner. The look is cleaner and one possible source of contamination is removed.
Cork and its engineered alternatives
Natural cork is still the reference closure for still wine. Its cell structure admits a trace of oxygen, and that slow exchange is what allows a well-stored wine to mature over decades. Spirits brands in the upper tiers increasingly use cork too, because the stopper raises perceived value.
The weakness is TCA contamination, the cause of "corked" wine, which the industry puts at roughly 1-3% of bottles. A luxury label cannot accept that defect rate, so many producers have moved to engineered corks:
- Agglomerated cork is made of cork granules bound with food-grade adhesive. It costs less than natural cork, performs more evenly and taints less often.
- Composite cork has an agglomerated core capped with discs of natural cork, so the face that touches the wine and the part the customer sees are both traditional.
- Synthetic cork is moulded from plastic polymers. It removes the TCA risk and costs considerably less, but it is the wrong choice for a wine meant to age. Spirits and RTD brands are taking it up as a taint-free stopper.
Crown caps beyond beer
The crimped metal crown is spreading from beer into hard seltzers, pre-mixed cocktails and RTD spirits, often through craft brewers adding those lines. It is pressed onto the bottle mouth at filling, and a pull-tab version spares the drinker an opener. Capping machines for crowns are fast; some handle thousands of bottles per hour.
Three things explain the return. A crown reads as small-batch and craft. It keeps oxygen out well, which matters for drinks with a short shelf life. And it looks different from the rows of screw caps beside it.
Pour spouts and dispensing fitments
A pour spout, in aluminium or plastic, fits into the neck and turns a standard bottle into a bar pourer. Flow rate is the design question: too fast and the bottle drips and spills, too slow and service backs up. Some brands commission custom-moulded spouts carrying their logo, which bar customers see at every pour.
Sports pour spouts add a spring-loaded valve that shuts when the bottle is upright, which stops the neck dripping and reduces waste. They cost more than a plain spout. A further step is an integrated system, where the glass neck, the closure and the dispensing hardware are designed together from the start. That gives a cleaner look and a more dependable seal than a fitment added afterwards.
Getting the neck finish right
The neck finish is the standardised profile at the bottle mouth, and it decides which closures will fit. When cap and finish do not agree, the cap cross-threads, leaks, or comes loose in the customer's hand.
Crown finishes are less forgiving than screw finishes. A single millimeter of variance can mean a failed seal and spoiled product, so dimensional control at the glass plant matters more for a crown bottle. When we match a project to a plant, we check the finish drawing against the closure specification before samples are made. Related reading: how plant capacity planning affects quality consistency.
Tamper evidence
Regulators in the EU, North America and, increasingly, Asia require some form of tamper evidence on beverage packaging, and the rules differ by market. Three methods are common:
- Breakaway band — the ring that stays on the neck the first time a screw cap is twisted off.
- Shrink sleeve — a film covering the join between cap and bottle.
- Induction seal — a foil liner inside the closure, heated by electromagnetic energy so it bonds to the glass rim and tears on first opening.
Brands often combine two of these, for example a shrink band over a breakaway ring. Induction sealing has spread from spirits into wine and craft beer.
Recyclability and newer materials
Aluminium screw caps recycle well on their own. The difficulty is everything attached to them: plastic liners, paper labels glued to the metal, tamper rings in a different material. Mono-material closures, in which every part can go into one recycling stream without separation, are the main direction of development.
Plant-based polymer liners and cork-derived composites are being researched as replacements for petroleum-based plastics, and so are closures that seal by mechanical interlock without liquid adhesives or sealants. None of these is ready for general use, so treat them as something to watch and not something to specify today.
How to choose for your project
Work through five factors and write the answers into your brief.
- Product. Still wine and spirits meant to age point to cork; vodka, gin and mass-market spirits to a screw cap; RTD and craft beer to a crown.
- Price tier. Upper-tier brands spend on natural cork, custom metal closures or integrated dispensing. Value brands prioritise unit cost and compatibility with the filling line.
- Channel. Bars and restaurants want pour spouts and sports caps. Retail needs clear tamper evidence and shelf appeal. E-commerce needs a closure that survives vibration and temperature swings in transit.
- Markets. Tamper-evidence rules, recycling mandates and import standards vary, and the closure must satisfy every country you sell in.
- Supply risk. Depending on one closure supplier or one material leaves you exposed; see our note on setting up a second source for glass.
The closure should be decided alongside the bottle design and filling process, not after them. Bottle shape and weight are covered in our articles on heavy-base vodka bottles, square spirits bottles, bottle choices for craft distilleries and luxury spirits presentation.