Food and Beverage Automation: CIP, Batching, PackML and Hygienic Design for PLC Engineers

Food and beverage automation uses PLCs, HMIs and SCADA to run batching, heat treatment, clean-in-place, filling and packaging, with traceability from ingredient lot to finished pallet. What sets it apart is hygiene: equipment is washed down daily, cleaning cycles must be proven and recorded, and packaging machines are increasingly programmed to the PackML state model.

The industry covers dairies, breweries, soft drinks, bakeries, confectionery, meat and ready meals. The products differ, but the automation divides the same way: a process side that makes the product in tanks and pipes, a packaging side that fills and packs it on fast lines, and cleaning that ties both to food safety.

The process side: batching and heat treatment

Batching. Ingredients are added by weight on load cells or by volume through flowmeters, in an order a recipe defines, with mixing times and temperatures. The ISA-88 model, which separates recipes from the equipment logic that runs them, is used here as in pharmaceutical automation: phases such as dose, mix, heat and transfer are written once, and products differ only in their recipes. Recipe management on the HMI or a batch server lets production switch products without a programmer.

Heat treatment. Pasteurisers hold a product at a set temperature for a set time. In a continuous pasteuriser, a flow diversion valve sends product back for reprocessing if the holding temperature drops below its limit. These are food-safety controls, so their instruments are calibrated on a schedule, and their records are kept.

Other loops. Fermentation temperature control, carbonation, standardisation of fat or sugar content and cooling all use the same analog measurement and PID techniques as any process plant.

Clean-in-place

Clean-in-place (CIP) cleans tanks, pipework and equipment without dismantling them. It is one of the most common programs a food automation engineer writes, and one of the most scrutinised.

Cleaning effectiveness depends on four factors, often drawn as Sinner's circle: time, temperature, chemical concentration and mechanical action (flow velocity in pipes, spray coverage in tanks). The PLC controls and records all four. Conductivity measures chemical strength and shows when a rinse has cleared the chemical. Flow is checked against the minimum the circuit needs. Temperature is measured on the return, not only at the supply, to prove the far end of the circuit was hot enough.

Route safety is as important as the cycle. Before a CIP starts, the PLC must prove that the circuit is isolated from product: mix-proof valves in the right position, swing bends or panels confirmed by proximity switches, and no tank on the route holding product. Many CIP sets recover the caustic and acid to tanks for reuse, adding level, conductivity and temperature control of the chemical tanks themselves.

Every cycle produces a record: which circuit, which steps ran, the measured values and whether any step failed. Production should not be able to start on a circuit whose last clean did not complete.

Hygienic design and the automation engineer

Hygienic design is mostly mechanical, but it reaches the automation engineer through the choice and installation of devices. The European Hygienic Engineering and Design Group (EHEDG) publishes guidelines on hygienic equipment design, and 3-A Sanitary Standards fill a similar role in the US, especially in dairy. In practice for automation this means:

• Sensors with hygienic process connections and surfaces that drain and can be cleaned.
• No dead legs where product can stagnate, which affects where instruments are mounted.
• Enclosures, motors and sensors rated for the washdown regime; IP69K ratings are common in wet areas, and our IP65 vs IP67 rating chart explains what each code means.
• Cable routing and glands that do not create ledges or gaps where dirt collects.

Packaging lines and PackML

Packaging lines join machines from different builders: filler, capper, labeller, case packer, palletiser. If each machine behaves differently, the line is hard to run and harder to measure. PackML, developed by OMAC and published by ISA as ISA-TR88.00.02, defines a common state model, operating modes (such as production, maintenance and manual) and a set of data tags called PackTags. Our PACK EXPO International 2026 preview covers where packaging automation is heading, from PackML to linear motor transport.

The distinction between Suspended and Held is the useful one. Suspended means the machine is ready but waiting on something outside it, such as no bottles arriving or the conveyor after it being full. Held means something inside the machine stopped it, such as a label reel running out. Because every machine reports the same states the same way, a line controller can coordinate them, and OEE can be calculated consistently across the line. Our MES and OEE guide shows how those states become performance numbers.

Traceability and quality checks

Food businesses must be able to trace ingredients back to their suppliers and products forward to their customers; EU food law, for example, requires this. On the line, automation provides the data: ingredient lot numbers scanned or entered at the point of use, batch records, and finished lot codes printed and verified. Quality devices such as checkweighers, metal detectors and vision systems that check labels and date codes (see AI quality inspection for when a trained model helps) must reject reliably, and the PLC should confirm each reject actually left the line.

Changeovers and allergens

Food lines change product often, sometimes several times a shift, and each changeover is a risk. Automation reduces it in three ways. Recipes download every parameter for the new product at once, so nobody retypes fill volumes or temperatures. Interlocks stop a line starting on a new product until the required clean has completed, which matters most when moving from a product containing an allergen to one that does not. And the changeover is recorded: which recipe was loaded, by whom, and when the first good product was made. Short, reliable changeovers are also one of the quickest ways to raise a line's OEE.

Free courses for food and beverage automation

• CODESYS and IEC 61131-3 Programming: ladder, structured text and SFC, the language that suits CIP and batch sequences. Our CODESYS guide shows how to start.
• Industrial Instrumentation and Process Control: temperature, flow, level, conductivity and 4-20 mA loops.
• HMI Design: Siemens WinCC and FactoryTalk View ME: screens, alarms, trends and recipes.
• Servo Drives and Motion Control: the motion behind fillers, labellers and case packers.

Every course is free in full, with credited video lessons, notes, practice tasks and one final assessment; no card is needed. The optional EDWartens Certificate of Completion is a small one-off fee, US$8.99 for the beginner courses and a little more for the intermediate servo course. It can be checked at edwartens.com/verification. It is not a vendor, EHEDG or food-safety qualification and is not accredited. Create a free account to start.

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