The first and most important concern when packaging beer is preventing contamination by two of the main culprits that reduce the shelf-life of beer, stray yeasts, and exposure to oxygen.
A very basic breakdown
The basic steps for transferring beer to bottles or cans are fundamentally the same.
1) Empty containers are rinsed and then blasted with CO2 to remove debris and any cleaning solution that may have been used in the rinsing cycle.
2) The container is purged with CO2 several times, pressurizing with CO2 prevents excess foaming when the beer is forced into the container under pressure.
3) Afterwards, the pressure is slowly relieved until the beer is at ambient pressure.
4) Next comes the capping machine or can lid. Before closing the container, the small air space between the beer surface and the bottom of the cap or lid needs to be purged.
a. On some bottling lines the bottle is passed under a narrow, high-pressure jet of water that hits the beer, causing it to foam up and drive the air out of the bottle. The cap is then applied before any oxygen can re-enter the bottle.
b. On canning lines a shot of CO2 is injected to drive out any oxygen just prior to seating the lid.
c. On other systems, fill head dive to the bottom of the bottle and slowly rise as the bottle begins to fill. This technique creates a positive motion where the filling nozzle dispenses beer below the level of the product. By utilizing this method, dissolved oxygen is reduced and a more complete “fill” is achieved with the proper amount of foam left on the bottle or can to force out remaining oxygen.
5) After the cap or lid is applied, the outside of the container is rinsed to remove any beer that may have foamed out during the process.
Filling Bottles Manually – many start-ups to medium sized microbrewers venture into the finished package market segment utilizing manual filling systems. These manual systems range from simple ball valve controlled units to more elaborate electronic fill valve controls. A most important consideration when filling cans or bottles manually is dissolved oxygen pick up. Controlling this can be a very tricky endeavor. One must be very resolute to ensure the minimum of dissolved oxygen pick. The best method for filling bottled beers is by way of a Counter Pressure filling head, which allows carbonated beer to flow into the pressurized bottle. Because the bottle is pressurized with CO2 gas, there is minimal loss of the saturated CO2 in the beer. When beer temperature and flow are just right, beer fills evenly and without excess foam. Without the use of a counter pressure filling head, filling beer would be nearly impossible due to the excess foam created when filling the unpressurized vessel.
Filling Cans Manually – beer can filling is somewhat easier than beer bottle filling. Because cans are not pressurized, a gravity type or stem valve can be utilized. With a gravity filler, beer must be chilled to just above freezing to reduce the amount of carbonation (foam) that outgases during the filling process. If beer is too warm, excessive foam will not allow for a consistent and or reliable fill levels.
When canning manually, the operator does the work that electronics would otherwise do in a more automated system. Essentially, the operator would manually place a can underneath a fill head then depress a start button to initiate the flow of beer. At minimum, with smaller systems, the beer output should be electronically monitored so the level of beer in the can is controlled. Controlling the fill levels by way of manual valves tends to increase dissolved oxygen levels and decreased CO2 content.
To begin with, and operator places a can (and in some cases, two cans) under a single or set of purge heads to purge the cans much the same as beer bottles as described above. After the cans have been purged with CO2 for a pre-determined time they may be moved under a gravity flow fill head where the filling process is initiated. In all cases, whether manual or automatic, foam is typically allowed to form a “head” and flow over the can lip in order to reduce the amount of dissolved oxygen in the finished product. If no head of foam is formed above the can, prior to applying the lid, the operator risks introducing an extreme level of CO2 thus shortening shelf life and affecting taste.
Automated packaging lines
Tooling up for automated packaging of your beer is an expensive and necessary undertaking in your journey to becoming a fully operational professional brewing facility with the ability to service the craft beer enthusiast consumer clamoring (hopefully) for your product in a growing marketplace. There are temporary or transitional packaging services you can use like contract packaging services or mobile canning or bottling services but, in the long run, having your own packaging line saves you in packaging expenses and gives you much greater control over the quality of the packaged nectar you worked so hard to create.
When evaluating your potential investment in a packaging system, there are more than simply machinery considerations that need to be included in your calculations.
1) Will your brewery be able to produce sufficient volume of beer to make this investment profitable? If not, are there contract packaging opportunities from other small beer makers you can capitalize on to offset costs?
2) On top of your investment in the packaging system there is the investment in the raw packaging materials themselves. Cans, bottles, six-pack carriers, labels, crown caps, case boxes, etc all have minimum print production limits (and don’t forget to include the one-time set-up costs for each printed packaging item) that can easily exceed the cost of making the beer itself. The result is a substantial additional investment in packaging material inventory.
3) Choosing a packaging system. When choosing a packaging line you really need to keep, along with physical power and space requirements, the future and scales of profitability in mind.
a. If you’re a small brewpub looking for a small footprint, low output system for a small amount of on and off premise sales, a mobile packaging service or a small filler system producing 15-30 units per minute, would probably work well.
b. For larger and growing breweries bottling is only profitable when done in volume. What’s considered volume? Industry experts say a brewery who’s serious about distribution should not consider a system that produces less than 50-60 units per minute. If opportunity presents itself, a higher capacity system may be an option if sales demand the larger investment required to purchase a high speed line.
Direct-Line or Tandem Processing – Direct Line bottling is a lower volume (8-30units 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. (usually 4 to 10) All functions should come from one supplier to make for easy warranty and troubleshooting.
To begin with, and operator loads empty bottles onto a Rotary Feed table to allow for accumulation of “bottles in waiting.” A Feed Table should be constructed for stainless steel with the revolving disk made of UHMW or another soft surface so as not to damage bottle bottoms.
Once bottles are loaded onto the Feed Table, they should be automatically transferred to an Internal Bottle Rinser, rinsing bottles is important in order to removed dust particles and debris that may have been picked up during the shipping process. The Rinser should automatically invert bottles over stainless steel rinse heads and be sturdy enough to hold multiple bottles at a time to maximize production requirements.
After the bottles have been rinsed, they move along the direct line conveyor and automatically position themselves under stainless purge heads. Most often, purging is done with CO2 to “push out” oxygen in the bottle which would otherwise contaminate the product. Since CO2 is heavier than air, it sinks to the bottom of the bottle, the oxygen is pushed out as the bottle fills with CO2. Once the oxygen has been removed, the bottles move to the next stage, the counter pressure filling head.
Critical to the correct packaging of beer is to quickly cap the bottle within seconds of filling so as to reduce the amount of oxygen that might otherwise enter the bottle. Once again, dissolved oxygen is any enemy of beer, so it’s best to minimize any opportunity for influx.
After the bottles have been purged, filled and capped, bottles should be rinsed and dried to remove as much beer residue and moisture that may have accumulated on the outside of the bottle. This can be done in a number of ways but most effectively by way of a direct line rinse and external air knife. Together, this dual function prepares your bottle to be packed in its final presentation carton prior to reaching its final destination – your customer!
Rotary fillers – most high speed bottling machines are rotary machines. Rotary systems have a carousel equipped with from eight to over 100 valves and bottle platforms. Rotary systems range from 20 BPM to over 1000 BPM and are available in both short- tube, and long tube designs.
Monoblock design – Monoblock systems are complete units that typically include bottle/ can rinsers, fillers and cappers or seamers. Typically, monoblock units are expensive to purchase and require highly technical operators to maximize production and minimize waste. Many craft beer operators prefer to start with simpler, in-line systems, for their production then grow into the high speed equipment when demand increases.
Fill Valves There are a wide variety of filling valve technologies simple gravity flow, overflow pressure valves and piston valve technology to name a few. However, with craft beer filling, two basic approaches apply; short tube and long tube. Both are gravity fed and fill under counter pressure but work very differently.
– Short tube fillers (aka: vent tube fillers) have a vent tube about 2″-3″ long which allows air or gas to escape the bottle as it fills with beer. Beer flows around the vent tube and over a small rubber spreader which directs the beer out to the walls of the bottle neck, where it flows down the inside walls of the bottle. No beer flows out through the vent tube in normal operation, in fact, the vent tube controls the fill level in the bottle–when the liquid level reaches the end of the vent tube, the flow stops. Fill adjustments are made by adjusting the length of the vent tube.
– Long tube fillers (aka: Quiet Fill fillers) use a long fill tube that fills the bottle from the bottom up. The bottle is filled to the top, and then the extraction of the fill tube lowers the volume to the desired fill height.
Purging and air reduction add-ons
Here are a few additional methods offered to reduce bottle air pick-up:
Pre-purging machines are one way to reduce bottle airs to near-null levels when using old vent tube fillers.
Nitrogen drip systems inject a measured drop of liquid nitrogen into the bottle immediately before the filler. The nitrogen drop then quickly expands to a gaseous form forcing air from the can or bottle.
Pre-evacuation retrofits employ a modified snifter valve (the valve which vents the counter pressure after the bottle is filled) to evacuate the bottle.
CO2 (and nitrogen) purging retrofits placing a gang of nozzles to inject the gas (purging nozzles) ahead of the filler.