Bottling. Breweries have been bottling their beer since the pre-industrial era, although bottling only first really took-off with the development of modern industrialization in the latter half of the 19th century. This was because glass bottles became much cheaper and much more accessible with the introduction of mass production. Partially as a result, many breweries started selling their beers into ever more distant markets.
It is difficult to generalize about the current importance of the different types of bottling, as this varies significantly from market to market, depending on the level of technology, tradition, culture, legislation, and geography. The different types of bottling technology used by breweries large and small today can be divided into the following categories:
Modern bottling lines for returnable bottles can handle anything from a few hundred up to about 100,000 bottles per hour. Such a bottling line will normally look like this: Empty bottles from the market are received in crates that are placed on a conveyor leading to the unpacker where the bottles are lifted unto a separate conveyor. The empty crates are normally washed in a tunnel before being transported to the packing end of the line. The bottles are then fed upside down into the baskets in the bottle washer, a large machine where the dirty bottles are transported through a number of different compartments where they are sprayed with and submerged in both caustic and clean water, thoroughly rinsing both their interior and exterior (including removal of old labels). The conveyor then transports the clean bottles to the either visual (very rare these days) or automatic inspection by an empty bottle inspector (EBI) for any remaining traces of liquid or dirt. It is worth noting here that in recent years, beer consumers in the United States have roundly rejected returnable bottles, apparently thinking them unsanitary. They are now exceedingly rare, and the tell-tale scuffed shoulder of the returnable bottle has almost vanished from store shelves.
Postcard depicting bottling machinery, c. 1910. pike microbrewery museum, seattle, wa
Whether brand new or recycled, the bottles are then fed into the filler, a large rotary device connecting the bottles to the bowl containing the beer ready for filling. But before beer is filled into the bottles, the air is sucked out of them to remove the harmful oxygen. This may happen either once or twice—single or double pre-evacuation—which is always followed by a pre-pressurisation with pure CO2 that serves to both provide a “beer friendly” atmosphere in the bottles and aligns the pressure in the bottle with the one in the tank, making sure that the subsequent filling can take place without the beer foaming. When the bottles are full, they enter the rotary capper where caps/crown corks are applied to the bottle mouths and squeezed tightly onto them.
In a large brewery the next step will usually be the tunnel pasteurizer, another very bulky machine that is essentially a huge shower with water increasing in temperature in the first half of its length and decreasing in the last half, controlled in such a way that each bottle gets a heat treatment that is sufficient to destroy any live microorganisms during its passage through the pasteurizer, leaving the bottled beer microbiologically stable. The pasteurized bottles are then fed to the labeller, and finally a full bottle inspector (FBI) that automatically checks filling height, capping, and labelling. From here the bottles will be conveyed to the packer where they are automatically packed into six-packs, cases, and/or crates.
On an aseptic bottling line there is no tunnel pasteurizer. Frequently, the task of ensuring microbiological stability of the beer is instead achieved by flash pasteurization or sterile filtration (
This technology was introduced in the 1990s and made possible by progress in the quality of PET and PEN bottles with respect to their barrier properties, the protection against CO2 escaping from the bottles and oxygen entering them. Both these phenomena are detrimental to the quality and shelf life of the bottled beer. Bottling lines for plastic bottles are very similar to aseptic glass bottling lines, as the bottle material does not allow tunnel pasteurization. On the most advanced of such bottling lines, the bottles are “blown”—produced from small plastic cartridges by hot air in moulds—just before entering the filling line.
The introduction of plastic bottles for beverages, including beer, on a large industrial scale took place in the 1970s following advances in the plastic industry allowing production of containers from either materials that in themselves provide sufficient barrier properties or producing these from composites—several layers of different plastics—giving combined, satisfactory wall qualities. Besides being much lighter than their glass counterparts, plastic bottles offer advantages with respect to safety, as they don’t break easily. Further, a new plastic bottle is significantly cheaper than a similar glass bottle. The most commonly used material is PET (polyethyleneterephtalate), a compound in the polyester family, that can be used as a single layer bottle for beer with a shelf life almost as long as glass bottles. A newer and still more expensive type of plastic for bottles is PEN (polyethylenenaphtalate) having the advantage over PET that its barrier properties is superior to PET and that it can be washed with caustic just like glass bottles, allowing PEN bottles to be used as returnable bottles for beer or other carbonated beverages. While consumers in many parts of the world are used to seeing beer in plastic bottles, the American consumer has yet to warm to this packaging, and it remains a rare sight. Recently, however, some mass-market brewers have introduced plastic bottles that have the same general appearance as glass bottles, and these are now increasingly seen at public venues such as stadiums.
Many different types of very simple machinery are available to brewers, allowing them to bottle very cheaply. In comparison to the technologies described above, these simple types obviously suffer from the disadvantages of having very low capacities—sometimes only up to a few hundred bottles per hour—and being very labor intensive. Consequently, this technology is found mostly in small craft breweries, and often in connection with bottle conditioned and barrel aged beers.