Labelling machines and date coding

By hand, the tool that matters is a jig: a cradle that holds the bottle at a fixed height and orientation with a stop for the label edge, so that a hundred bottles come out with the label in the same place. Applying labels freehand is possible and the result announces itself on a shelf. A hand-cranked semi-automatic applicator is the next step and is cheap: the bottle is rolled across a peel plate, the label is transferred and wiped down, and a person feeds it.

Wet-glue machines are the traditional method and remain common in beer and wine. A paper label is picked up, passed over a glue roller and wrapped onto the bottle by a set of brushes or pads. The labels themselves are cheap, the finish is characteristic, and the machines are mechanically involved and need a clean glue system. Wet glue also demands a dry bottle: it will not stick to condensation.

Pressure-sensitive labelling is now the default for small and medium producers. Labels come on a reel with a release backing, the backing is pulled sharply around a peel plate, the label lifts off, and the pack — rolling past on a belt or turned by a set of rollers — takes it and is wiped down. It handles front, back and neck labels, it is easy to change over between products, and the consumables cost more.

Registration is the recurring practical problem. A round bottle has no natural reference, so applicators locate the mould seam, use a sensor on a previously applied label, or simply rely on consistent presentation from the infeed. A label a few degrees out of square is visible from across a room in a way that nothing else on the pack is.

Almost always because of moisture and temperature at the moment of application or afterwards. Adhesives are formulated for a service condition: an adhesive specified for ambient application and ambient storage will let go on a bottle that goes straight into a chiller and sweats, and one specified for wet, cold service will behave differently on a warm dry line. Where a cider will be sold from an ice bucket, that has to be said to the label supplier before the reel is ordered.

The bottle surface matters as much as the adhesive. New glass carries a coating applied at the works to protect it in handling, returned glass carries whatever the wash left, and either can be enough to prevent a good bond. A bottle that has been rinsed and not properly dried will not take a pressure-sensitive label reliably and will not take wet glue at all.

Face stock is the third variable. Uncoated papers look right for a traditional cider and wick moisture, so they cockle and stain in a chiller; coated and synthetic stocks resist that and read differently. And a flat label wrapped onto a strongly curved or shouldered bottle will lift at the edges no matter what the adhesive is — the label has to be sized for the bottle, not for the artwork.

A lot code identifies the batch. It is what links a pack in a shop to the fermentation, the blend, the fill date and the records behind them, and it is the mechanism by which a producer can withdraw a specific run instead of everything they have ever made. In most jurisdictions marking a lot is a legal requirement in its own right, distinct from any date marking, and the requirement is worth confirming locally rather than assumed from another country’s practice.

Applying it is a small industry of its own. Continuous inkjet fires a stream of charged droplets and prints on the move at high speed. Thermal inkjet uses a cartridge and prints a crisper code more slowly. Thermal transfer prints onto the label material, usually before or during application. Laser coders ablate a mark into the label or etch the glass and use no consumable at all, at the cost of a machine and an extraction system. At the smallest scale a hand stamp on the back label, or writing on it, is entirely adequate.

Whatever applies it, the code has to survive. Ink on a bottle that will spend a week in a wet chiller must be a formulation that stays there; a code printed on a label that will cockle is a code that will not be readable at the moment it is needed. Codes are checked on the line, not assumed, and the check is one of the few line checks worth doing on every pallet.

The other half is the record. A code that is applied faultlessly and matched to nothing in the cider house records achieves nothing. The traceability chain runs from fruit intake through the vessel, the blend, the fill and the pack, and the lot code is only the visible end of it.