In packaging, a Bag-In-Box or BIB is a type of container for the storage and transportation of liquids. It consists of a strong bladder (or plastic bag), usually made of metallised film or other plastics, seated inside a corrugated fiberboard box. The bag is filled by the manufacturer with the desired liquid and sealed.
For use, the customer tears open a pre-cut window at one end of the box and connects a nozzle to a built-in port on the bag to pump out its contents.
The BIB has many common commercial applications. The most ubiquitous uses of BIBs are for wine and to supply syrup to soft drink fountains, and bulk supplied condiments such as ketchup or mustard, in the foodservice context. BIB is also used to dispense sulfuric acid for filling lead-acid batteries in garages and dealerships.
The user is generally advised to not take the bag out of the box, as the bag alone may not be able to contain the internal pressure from its contents and could rupture. After the contents are exhausted, the entire box and bag inside is typically discarded rather than refilled.
The wine cask (or wine box) was invented by Tom Angove of Angove's, a winemaker from Renmark, South Australia, and patented by the company on April 20, 1965. Polyethelene bladders of 1 gallon (4.5 litres) were put into cardboard boxes for sale to consumers. The original design required that the consumer cut the corner off the bladder inside the box, pour out the desired quantity of wine and then reseal it with a special peg.
In 1967 C.H. Malpas and Penfolds Wines patented a plastic, air-tight tap welded into a metallised bladder, making storage much more convenient for consumers. All modern wine casks now utilise some sort of plastic tap, which is exposed by tearing away a perforated panel on the box.
The chief advantage to bag-in-a-box packaging is that it prevents oxidation of the wine during dispensing. After opening, wine in a bottle is oxidized by air in the bottle which has displaced the wine poured; wine in a bag is not touched by air and thus not subject to oxidation until it is dispensed. Cask wine is not subject to cork taint or spoilage due to slow consumption after opening.
After the wine is drunk and the bag is empty, the bag may be removed from the box and blown up through the tap valve like a balloon. The inflated bag makes a convenient pillow.
However, the bag is not hermetically sealed and has an unopened shelf life shorter than bottled wine. Most casks will have a best-before date stamped. As a result, it is not intended for cellaring and should be drunk within the prescribed period.
Bag in a box packaging is also preferred by producers of more economical wines because it is less expensive than glass bottles. Unlike bag-in-box packaging of other liquids, wine is not under pressure so it is perfectly safe to remove the bladder from the box. A bag of wine, once removed from the box, will float on water; this allows quick cooling of a white wine by immersion in an ice bath.