All fillers have a bowl or similar device to receive beer from the bright beer tank for distributing the beer to the various valves. Filler bowls vary from relatively small center bowls to torus or doughnut-shaped ring bowls to separate bowls placed at a distance from the filler. A gas pressure-regulating and/or -relieving valve maintains bowl pressure, and the beer level in the bowl is maintained by a float or by conductivity probes or differential pressure tubes. With the float method, the float usually opens and closes a port as it raises and lowers.
Filler Bowl Operations
The filling unit or filler bowl should be cleaned and sanitized before bottling. To prepare for filling, the beer lines, hoses, and filler should be cooled down using cold water. The water should be blown out before beer is introduced into the filler. The system is then pressurized, and beer is supplied to the filler bowl from the bright beer tank. Some brewers will vent the bowl pressurizing gas prior to the introduction of beer to lower the oxygen contact with the incoming product.
Types of Bottling Machines
The bottles are delivered on a conveyor belt, separated at a predetermined spacing by a separating device, and positioned on a lifting platform under the filling elements by a star wheel infeed device. Basically, for the brewer, there are two types of bottling machines available.
Tandem or direct line bottling is a lower volume (8–30 units per minute) most applicable to the growing craft brewer. Direct line systems allow an operator to rinse, fill, cap, label, and post rinse bottles on one line (Figure 17.7).
All high-speed machines are rotary machines as shown in Figure 17.8. These have a carousel with anywhere from eight to more than 100 valves and bottle platforms, and range in speed from 20 BPM to more than 1,000 BPM.
Filling Valve Technology
Beer can be introduced into the bottle via a filling tube. The filling tube is made up of a tube through which the beer passes and a return gas vent at the level of the required filling height. Some high-speed fillers (>1,000 bottles/min) operate without filling tubes. There are two basic types of filling valves, short tube and long tube. Long or short tube refers to the length of the tube associated with the filling head. They work differently, but both fill under counter pressure (the bottle is counter-pressurized to the same pressure as the filler bowl above the valves containing the carbonated beer) and the product flows by gravity into the bottle.n tunnel pasteurization, and (5) less of an impact on flavor than tunnel pasteurization.
Short Tube Fillers
The first kind of filling tube is very short and sticks into the bottle only a short distance. Short tube fillers have a vent tube about which exhausts the air or gas in the bottle as it fills with beer. The product flows in around the vent tube and over a small spreader which fans the product to the walls of the bottle neck, where it cascades down the inside walls of the bottle.
Long Tube Fillers
Long tube fillers use a long fill tube which extends nearly to the bottom of the bottle to fill the bottle from the bottom up. With a long vent tube system for filling to a level, there are two passages in the filling tube. Beer moves through the large passage in the tube to the bottom of the bottle. As the beer level rises in the bottles, the displaced gas escapes through the smaller passage in the tube.
Pre-Evacuation, Counter-Pressure, and Filling
The bottles are lined up and placed one after the other into the filler and are attached to the filler arm that comes down and seats on the sealing surface of the bottle. In pre-evacuation, the bottle is pressed airtight against the filler valve and air is evacuated creating a partial vacuum on each bottle. The next step, whether or not pre-evacuation is used, is introducing counterpressure into the bottle. This step provides pressure inside the bottle sufficient to preserve product carbonation, that is, enough to keep the pressure of the gas in contact with the beer above the equilibrium point during filling so that carbon dioxide is not released from the beer.
Post Air Evacuation
Once the bottle has been filled and dropped away from the filler valve, it is necessary to clear the head space of oxygen prior to crowning. Any entrained air beneath the crown will quickly oxidize the beer. This is done by creating foam in the bottle neck, with the foam rising and displacing the gas in the head space.
Bottle knockers are used on relatively slow-speed bottle fillers.
The ultrasonic foamer utilizes an ultrasonic generator and a transducer with a stainless-steel shoe that contacts the bottles while they are still on the filler.
Jetters, i.e., fobbers are devices that shoot a high-pressure jet of sterile deaerated water into the head space of the bottle neck. This excites the top layer of beer, causing the beer to foam before it enters the crowner. The most important parameter determining the amount of foam is the pressure of the water jet.
Sterile filtration has the advantage over pasteurization of giving very gentle treatment to the beer; with no heating and cooling there is no potential for flavor changes. The additional filtration can also improve non-biological stability and clarity of the beer. Sterile filtration physically removes beer spoilage organisms from the beer as it passes through a cartridge membrane filter. It is essential the beer first undergo primary diatomaceous earth filtration or sheet pad filtration before it undergoes sterile cartridge membrane filtration.
After crowning, the filled containers are conveyed past a fill-check unit. This unit can be adjusted to reject any container that has a low fill, a headspace not filled with beer foam, or a bottle that lacks a cap. The fill-check unit, if installed after the filler, must be installed downstream from the filler at a point where the beer is quiet and the foam has not yet started to settle.
Post Bottle Rinsing and Drying
When a bottle comes off the filler, it receives a post rinse treatment to wash off the foam, and is then passed through a blower to remove the bulk of the water.
Click on the following topics for more information on bottling beer.