- By Jason Wilson
After attending a local beer brewery tour several years back, I became fascinated by the detailed science and math underlying the production process. It did not take long for me to become a homebrew enthusiast, and in 2012 my wife and I fermented our first beer batches using a commercial kit of the type used by thousands. I would label these first three attempts as “not so good,” but I was intrigued by the concept and kept improving my skills.
With a day job completely unrelated to the beer brewing field, it was necessary to learn more by reading books and gathering information on the topic. As time passed, I upgraded equipment and improved my skills, so I could have progressively better results. Realizing that progressing would demand careful control of the brewing process, it became important to research how to automate the system.
Recipe for success
The basic recipe for beer has been around for a very long time. Barley grain is malted, which means it is soaked in water and allowed to germinate, then dried and sometimes roasted, or kilned. At the brewery, this grain is crushed and introduced into hot water, creating the mash, and the heat converts the grain starches into sugars. The mash is boiled with hops to create unfermented beer, or wort. The wort is cooled, and then the yeast is introduced to perform the fermentation process of converting sugars into alcohol. Temperature control figures prominently at every step.
For instance, during the mashing process there are various enzymes that are activated once the temperature rises to a certain point, and then denatured once the temperature moves a little higher. One enzyme might be activated at 149°F and denatured at 152°, while other enzymes have varying and sometimes overlapping temperature ranges. The resulting final product’s flavor is affected by which enzymes are active for how long, so the brewer needs to control the mash accurately to a target temperature profile for a specific time to take advantage of various flavor-impacting enzymes during the process. Even with a mechanical or digital thermometer, this is exceedingly hard to do by hand, and even in the best case requires constant manual attention and intervention.
Most homebrewers start with small kettles, burners, a cooler, and some other accessories—all of which they work manually. Results can be quite good, but obviously the manual steps can introduce a lot of variability and are time consuming. As homebrewers become more proficient, they recognize the need to gain better control of the process to make consistent and improved batches and confidently track improvements (figure 1).
With upgraded small-batch kettles and burners at hand, the next step was to reach out for inspiration from an acquaintance who teaches automation at a nearby technical college. Without any specific training in electrical, instrumentation, or controls programming, the complexity and expense of automation systems seemed a little intimidating. Hopefully, my hands-on handyman experience would be enough.
A key outcome of this connection was becoming introduced to the AutomationDirect website, where it quickly became clear how the company’s solenoid valves, sensors, industrial controllers, and other associated items could help to automate a brew system. The parts were economical, and there was plenty of support information available to help build confidence. Also, it was quick and easy to obtain additional pieces and parts as the project developed.
Even without a programming background, it was easy for this first-time hobbyist to learn about and use the software (figure 2). The AutomationDirect website offered many helpful technical support documents and videos, and when it became necessary to reach out for phone support to get past a minor snag, their experts were very knowledgeable and helpful.
The first task was to automate the monitoring and control of temperature. The solution was to use an AutomationDirect CLICK programmable logic controller (PLC), with thermocouples wired to inputs using thermocouple extension wire, and the outputs connected to solenoids regulating gas flows. The burner was controlled to maintain temperature using on/off logic, and multi-event recipes allowed detailed configuration of time and temperature set points for each step (figure 3).
Another next step was to automate some of the brute-force tasks, such as filling and emptying the kettles. With a little plumbing, and some float level sensors and solenoid valves wired to the PLC, it was possible to control each of these steps accurately (figure 4). Almost all these products were stainless steel or food-grade components sourced from the AutomationDirect website.
With the basics well in hand, the project was soon moving into more advanced capabilities. After learning how to use a smartphone as a mobile human-machine interface (HMI), various HMI displays were configured to monitor the brewing status and change set points. The PLC was configured to perform some data logging to create a record of each batch, helping to replicate the best batches in the future, and enabling decisions to be made about how and where to improve the recipe. With mobile/remote monitoring capability, it is now possible to confidently go jogging or do anything else while brewing beer, instead of hovering over the system like a mad scientist.
Brewing into the future
Bill Owens, who founded America’s first brew pub in 1983, once said “Give a man a beer and waste an hour. Teach a man to brew and waste a lifetime.” Many would say the word “waste” is a bit strong when describing a beverage that is among the most-consumed worldwide and is found in almost every culture, but one can see how it is easy to get excited about this hobby.
Today, the homebrew system is still under development, but none of the time spent so far has been a waste. On the contrary, it has been fun refining the brewing process and improving recipes. The experience with AutomationDirect products and the system built using them has delivered a lot of flexibility to experiment, and one day may enable the operation to be scaled up to a commercial level.
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