Brewing beer involves both art and science and requires precise control of various variables to consistently produce high-quality beer. Temperature control is a crucial factor in the brewing process as it directly affects the flavor, aroma, and mouthfeel of the beer. Many breweries and brewpubs use specialized control panels to regulate temperature and other parameters during brewing.
There are two common types of control panels used in brewing: PID (proportional-integral-derivative) and PLC (programmable logic controller) control panels. While both serve the purpose of temperature regulation, they differ in functionality, complexity, and cost.
PID control is a widely-used method for regulating temperature in brewing due to its significance in the brewing process. It comprises three components – proportional, integral, and derivative – that work together to maintain the mash or wort temperature at a set point.
The proportional component responds in real-time to temperature changes by comparing the current temperature with the desired setpoint. If the actual temperature exceeds the setpoint, it decreases the power to the heating element, causing the temperature to decrease. Conversely, if the actual temperature falls below the setpoint, it increases the power to the heating element, raising the temperature.
The integral component adjusts the control output based on the duration of temperature deviation from the setpoint. If the temperature remains off-target for an extended period, the integral component increases the output to correct it faster.
The derivative component predicts future temperature changes by analyzing the rate of change in the present temperature. This prevents overshooting or undershooting of the setpoint, which can result in off-flavors or quality issues.
By working in harmony, these three components ensure better temperature control and consistency in the mash or wort.
PLC (Programmable Logic Controller)
PLCs are digital computers designed for industrial automation and control applications. They consist of hardware and software components, including a CPU, memory, input/output (I/O) modules, and a programming language. The programming language is used to create programs that run on the PLC and control the I/O modules.
The hardware components of a PLC system vary depending on the specific application but generally include a CPU, power supply, input modules, output modules, and communication modules. The CPU is the core of the PLC and performs necessary calculations and logic operations. The power supply provides electrical power, while the input and output modules establish connections between the PLC and physical devices like sensors, valves, and motors. Communication modules enable the PLC to communicate with other devices or systems.
PLC systems find application in controlling various brewing processes such as temperature regulation during fermentation and maturation, filling and packaging, and recipe management. In a typical brewery or brewpub control system, temperature sensors, pressure sensors, and other input devices are connected to the PLC input modules. The PLC program uses this input data to control the output modules, which are linked to valves, pumps, and other control devices.
For example, during fermentation, the PLC can regulate the beer’s temperature by opening or closing a cooling valve based on readings from temperature sensors. The PLC can also monitor fermenter pressure and adjust the relief valve automatically. Automation of these processes ensures consistent production of beer to the desired specifications.
PID vs. PLC Control Panels in Brewing
Both PID and PLC control panels play a significant role in brewing control, but they differ in functionality, complexity, and cost.
PID control panels are generally simpler and less expensive compared to PLC control panels. Their primary purpose is temperature regulation and maintaining consistency in the brewing process. They use a feedback loop to monitor temperature sensors and adjust heating elements, pumps, and valves to maintain a stable temperature within a narrow range.
PLC control panels are more complex and expensive. Apart from temperature regulation, they can control multiple processes such as pump control, valve control, and overall automation of the brewing process. PLCs can also integrate other systems like data logging, recipe management, and remote access.
PID control panels are usually simpler to operate, with intuitive interfaces and fewer programming requirements. On the other hand, PLC control panels can be more complex and demand higher technical expertise for operation and maintenance.
In a fully automated and standardized brewery, a PLC control panel may be the preferred choice. It can automate various steps in the brewing process, allowing brewers to focus on other aspects of operation. However, in a brewpub where the brewing process is more artisanal and hands-on, a PID control panel may be more suitable. It provides precise temperature control and consistency while allowing the brewmaster to make adjustments based on their knowledge and experience.