Dairy Plant Cleaning: Milkstone & Protein Removal

How to use this guide

This is a practical decision aid for dairy CIP teams. Use it to align procurement, EHS, QA, and operations on selection criteria, acceptance checks, and monitoring signals. When you have site-specific constraints (allergen control, wastewater limits, or sanitizer restrictions), share them with us so we can propose compliant, supply-ready options.

Where it fits

• Process goal: choose what you are optimizing (hygiene, uptime, energy, water use, corrosion risk, cost).
• Operating window: temperature, concentration, time, and flow/impingement (mechanical action).
• Interfaces: stainless grades, heat exchangers, elastomers (EPDM/NBR/silicone), seals, and spray devices.
• Constraints: food-contact rules, odor/chlorine limits, discharge limits (pH, COD, phosphorus), site EHS rules.

Key decision factors

• soil mix (milk fat + proteins + minerals) and where it builds (plates, dead legs, valves)
• CIP/SIP parameters (time, temp, concentration, flow) and line length/hold-up
• material compatibility (316/304, weld quality, gaskets, aluminum/brass peripherals)

What milkstone is (and why pairing matters)

“Milkstone” is typically a mineral/protein scale (commonly calcium salts plus organics) that hardens with heat and time. Removing it reliably usually needs alkaline cleaning to lift fats/proteins and acid cleaning to dissolve mineral scale. If either step is weak, the next step has to do “double duty” and defects show up.

• Alkaline step: targets fats and proteins; temperature and mechanical action are major levers.
• Acid step: targets calcium/mineral scale; effectiveness depends on acid type, chelation, and temperature.
• Rinse quality: poor rinsing can neutralize the next step and drive deposits (and corrosion) instead of removal.

Temperature windows (common failure mode)

• Too cold: fats stay viscous; proteins can smear; wetting is slower.
• Too hot (wrong chemistry): proteins can “bake on”; foam control becomes harder; corrosion risk can increase.
• Heat exchangers: thin films + high surface temperature accelerate deposit formation; confirm the hottest spots.

Chemistry pairing (what to decide)

• Alkaline cleaner type: detergency + sequestration; choose low-foam/high-foam based on system design and return line behavior.
• Acid cleaner type: choose based on scale type, stainless compatibility, and wastewater constraints.
• Chelants/sequestrants: help keep dissolved minerals from re-depositing (especially with hard water).
• Sanitizer choice: consider microbial target, contact time, and compatibility with stainless and elastomers.

Quick checks (shop-floor friendly)

• Visual + touch: chalky/rough surfaces suggest mineral scale; greasy feel suggests fat carryover.
• Conductivity/titration: confirm concentration at the point of use (not just the tank).
• Return line behavior: foam, air entrainment, and temperature drop can explain “mystery” failures.
• Rinse endpoint: set a measurable endpoint (conductivity/pH) rather than “looks clear.”

Specification & acceptance checks

When comparing products, ask for the data you can verify on receipt:

• Identity: product name, grade, manufacturer, and batch/lot traceability.
• Quality: typical COA items (appearance, concentration/assay, density, pH, viscosity).
• Packaging: drum/IBC/bulk, liner type, closures, and labeling.
• Safety: up-to-date SDS, handling precautions, and required PPE.
• Food-contact/compliance: any required declarations for food plant use (as applicable to your site rules).
• Logistics: lead time, Incoterms, shelf life, and storage requirements.

Handling & storage

• Store in original, sealed packaging, away from incompatible materials (separate acids and caustics).
• Use secondary containment and clear labeling in the operating area.
• For transfers: verify pump/hoses for caustic/acid service and implement spill-control basics.

Troubleshooting signals

If performance drops, these are common early indicators and what to check first:

• Milkstone persists / rough plates: acid strength at point of use, acid type, chelation, rinse endpoint, hottest surface zones.
• Protein soils not removing: alkaline temperature window, flow/impingement, surfactant package, concentration drift.
• Foam overflow in CIP return: air entrainment, pump shear, surfactant balance, defoamer compatibility, temperature.
• Stainless staining/pitting: chloride exposure, sanitizer choice/concentration, dwell time, rinse quality, gasket issues.
• Odor carryover: inadequate cleaning, biofilm niches, sanitizer contact time, rinse sequence.

If you share your current chemistry, operating window, and a few measurements (supply/return temperature, concentration at point of use, rinse conductivity/pH), we can usually narrow down the cause quickly.

RFQ notes (what to include)

• CIP steps and parameters (alkaline/acid/sanitize sequence; time, temp, concentration; flow/pressure).
• Soils + equipment focus (HTST/pasteurizer, plate heat exchangers, tanks, fillers, brine systems).
• Materials of construction (316/304, weld/passivation status; gasket/elastomer types).
• Water quality (hardness, alkalinity, silica if known) and rinse water source.
• Wastewater constraints (pH, COD, phosphorus, chlorine restrictions).
• Target KPI and acceptance criteria (visual standard, conductivity endpoint, micro targets).
• Estimated monthly volume and packaging preference.
• Country of delivery and any compliance requirements.

Educational content only. Always follow site EHS rules and the supplier SDS for safe use.