The Twinline cork with two natural cork disks on both ends represents a perfect combination of the agglomerated body and the natural cork for economic, technical, and aesthetic reasons. With Gultig’s resin coating, it offers the following characteristics: perfect adherence to the bottle neck, limited contact with the wine, and additional protection against “off-flavors” from cork or binder.

Technical Wine Cork with Two Natural Cork Disks

Length: Standard 39 mm and 44 mm
Diameter: Standard 24 mm, optional 23.5 mm
Tolerances: Length: average +/- 0.5 mm, standard deviation max. 0.4 mm, Diameter: average +/- 0.4 mm, standard deviation max. 0.3 mm
Disk thickness: ≥ 4 mm
Disk quality: 4 grades
Wash: Guaranteed without chlorine or oxalic acid
Sterility: Wine sterility by autoclave processing as well as SO2 treatment according to Gultig’s process
Residual Peroxide: < 0.2 ppm
Granule size: 3-7mm
Granule & Disk adhesive: Polyurethane, comply with FDA 170-199, 2002/72/EC
Production process: Steam pressure process, resin coating
Torsion: >6 daN/cm2
Extraction force: Average 200-400 N
Humidity: Adjusted to the customer’s bottling requirements +/- 1.5 %
Surface treatment: Silicone polymers, comply with FDA 73-575 and 181-28; EC 1935/2004
Options: Ink branding on the sides, fire branding on the ends
Other: Special sizes upon request
Advised bottle storage: Upright or horizontal in a warehouse preferably at constant temperature
Advised period of storage: Depends on quality of natural cork disks

Handling and Packaging

Storage: Natural corks should be stored in a well-aired odor free area at about 18°-20°C.

  • If stored below 15°C, natural corks can become hard and brittle resulting in imperfect sealing.
  • If stored above 25°C, natural corks can become too soft. This could result in the corks coming out of the bottleneck.

Storage before bottling: Natural corks should be stored at least 24 hours before being used at 18°-20°C.

Bottles: Use only bottles whose neck has an inside diameter that corresponds with the following standards:

Wine bottles: DIN EN 12726
Champagne bottles: DIN 6094-5

Corking jaws: The corking jaws should be regularly examined for damage before and during use. Damaged jaws may cause creases and other irregularities to the cork; leakers and increased cork dust may result. When fully compressed, jaws should not close to more than 16 mm.

Corker: In order to avoid cork dust, the following parts of the corker should be carefully examined before use:

  • Hopper, or any moving parts of the hopper: to determine if any sharp edges are detected
  • Cork shoot or tube: to determine if any sharp edges are detected
  • Corking jaws: (see above)
  • Heated jaws should not exceed 80°C
  • Star wheel should be appropriate for the bottle diameter

The centering cone and plunger should be examined for exact placement above the bottle resulting in an optimum seating of the cork in the bottleneck.

Filling height: The filling height depends on the type of bottle, the cork length and the temperature of the wine at bottling: For a standard claret bottle with a 44 mm long cork at 20°C, there should be 55 mm of space between the lip of the bottle and the wine itself; this would be about 11 mm head space. With a cooler wine, the filling height is correspondingly lower; with a warmer one, correspondingly higher. (Please refer to our bottling fill level chart).

Internal pressure: The internal pressure of the bottle should be examined at regular intervals. For vacuum corkers, once per hour is advised. The needed resting time after corking depends on the internal bottle pressure.

Bottles neck up or laid down: About three hours after corking, the natural cork regains 95 % of its original diameter; after 24 hours 99 % of its original diameter. (Depending on the cork’s moisture, these times may vary slightly).

Ideally, to avoid leakers due to positive head pressure in the bottleneck, bottles should remain upright for 24 hours. In the case of pressure reducing devices such as CO2 injection or vacuum corkers, maintaining bottles upright for 5 minutes is adequate.

Storage and transport of bottled wines: Great variations in temperature during the storage and transport of bottled wine should be avoided. The changes in volume causes by temperature variations may result in corks moving up or down the bottleneck resulting in leakers.