Patience is a trait that brewers cultivate from the very first batches they brew. Remember the agonizing wait for your first bottles to condition or for that first keg to force carbonate? Experience and a steady pipeline help ameliorate the painful wait for beer to finish its last step, but even at the biggest production breweries, brewers are always watching the clock and always wishing things would go just a little bit quicker.
In the October/November Gearhead column (“The Force Behind the Fizz”), we looked at how some brewers, especially lager brewers, are using natural carbonation to imbue their beer with bubbles, but the far more common technique is static-force carbonation. The typical setup uses a carb stone in a bright tank, and through controlling temperature, pressure, and time, brewers can dial in the exact level of carbonation they are shooting for. It’s foolproof, but the time it takes is a precious resource in the brewery. Carbonating beer in a bright tank can take anywhere from a few hours to a few days, and this lag time at the end of the brewing process can wreak havoc on the production schedule. While good brewers are not known for taking shortcuts, an efficient brewer is a profitable brewer, and a streamlined process can be the difference between meeting production goals and leaving orders unfilled. Instead of filling a tank with beer and waiting for it to carbonate, many brewers are using an in-line carbonation system to inject carbon dioxide into the beer as it moves from one vessel to another.
A variety of systems for in-line carbonation is available, and the technique scales from large production breweries, such as AleSmith (San Diego, California) and Modern Times (San Diego, California), down to the homebrew level. The way they work is simple and similar from the largest commercial installations down to the homebrew scale. The home brewery setups, such as Blichmann Engineering’s QuickCarb, are particularly simple: A pump pushes beer from one vessel (say a secondary fermentation vessel) past a thumb-sized carb stone mounted perpendicular to the flow in a T-junction and into a second vessel (say a corny keg). A regulated tank of CO2 is connected to the barb on the end of the carb stone, and gas bubbles through the stone and into the liquid. By the time the beer reaches the destination vessel, it’s carbonated to spec. The exact carbonation level of the finished beer can be dialed in by adjusting how much gas pressure is applied to the stone. Since the solubility of carbon dioxide into liquid depends on the temperature of the liquid, you can look up the pressure values on the “carb chart” (see “In-line Carbonation: DI-WHY?”, below). Once the process is dialed in, the system will carbonate a five-gallon batch in about an hour. The commercial systems do the same thing, but the calculations are handled by controller software.