Raw Milk Reception & Handling

The Reception Process Flow

1. Tanker arrival and weighing — weighbridge before discharge
2. Sampling — representative sample for laboratory testing
3. Antibiotic / inhibitor screening — rapid test (8–15 min) before tanker discharge
4. Tanker discharge — pump-down through filter and meter
5. Filtration — nominal 100 µm to remove gross extraneous matter
6. Deaeration — remove air picked up during pumping (some operations)
7. Cooling — plate cooler to 4°C if not already at temperature
8. Metering and tracking — volume meter; batch identifier assigned
9. Storage — into chilled bulk milk silo (typically 50,000–500,000 L)
10. Tanker CIP — tanker washed before departure
11. Reception bay CIP — daily clean of discharge pipework

Reception Bay Design

Layout considerations

• Drive-through layout — preferred over reverse-in; saves driver time, reduces accidents
• Covered or enclosed reception — protects against weather, contamination, vermin
• Multiple discharge points — for larger plants accepting multiple tankers simultaneously
• Tanker washing facility — CIP available before departure
• Driver facilities — rest area, toilet, sample documentation area
• Reception bay drainage — rapid drain-off of spills and washdown

Equipment specification

Raw Milk Quality Tests at Reception

See milk grading for the full framework. Tests applied at reception:

Cold Chain Management

Cold chain integrity is critical to raw milk quality:

• Tanker arrival temperature — must be <6°C (UK regulation); ideally <4°C
• Discharge cooling — plate cooler to bring any warm milk to <4°C before storage
• Storage temperature — <4°C, ideally 2–3°C
• Silo cooling — jacketed or coil cooling; agitator to prevent temperature stratification
• Continuous monitoring — T sensors on silos with alarms; data logging
• Holding time — minimise; ideally process within 24–48 hours

Common Reception Issues

Storage Tank Hygiene

Bulk milk silos require rigorous hygiene management:

• Daily CIP — full clean of empty silos and connecting pipework
• Inspection access — hatches for visual inspection; cameras for remote monitoring
• Maximum hold time — typically 48–72 hours before forced use or disposal
• Stratification prevention — gentle agitation to maintain temperature uniformity
• Air exposure — minimise headspace contamination; nitrogen blanket for some operations
• Microbiological control — periodic swab testing of CIP-cleaned surfaces

Reception Documentation

Modern reception must capture full documentation for traceability:

• Driver and tanker identification
• Source farm(s) and pickup time
• Receipt time and temperature
• Antibiotic test result (signed)
• Discharge volume (weighbridge and meter cross-check)
• Compositional results (fat, protein, lactose, SCC, TBC)
• Receiving operator sign-off
• Destination silo and lot number
• Any deviations or rejections (with reason)

This documentation is increasingly captured electronically via reception management software integrated with the plant's MES and ERP systems.

Frequently Asked Questions

What temperature should raw milk be received at?

Less than 6°C is the UK regulatory limit; ideally less than 4°C. Receipt above 6°C triggers an investigation; receipt above 8°C typically causes load rejection. The cold chain from farm tank to dairy silo must be maintained throughout transport — refrigerated tankers, short transport times, immediate discharge on arrival.

Why is antibiotic testing done before tanker discharge?

Because zero tolerance applies — a positive antibiotic result means the entire tanker load must be rejected and disposed of. Testing before discharge prevents contamination of plant silos and downstream products. Modern rapid tests (Charm SL, IDEXX SNAP) deliver results in 5–15 minutes, fast enough to make the decision before discharge starts.

What is a deaerator and do I need one?

A deaerator removes entrained air from milk under partial vacuum. Air pickup during pumping causes foaming, lipolysis acceleration, and downstream processing problems. Most modern reception lines include a deaerator after the discharge pump. Larger plants and those producing UHT, infant formula or high-protein products find deaeration particularly valuable.

How big should milk reception silos be?

Sized for 1–3 days of plant production typically. For a 200,000 L/day plant: 3–5 silos of 100,000–200,000 L each. Multiple smaller silos give more flexibility (segregation, dedicated supplier silos) than one giant silo. Silos should be insulated, cooled, and CIP-capable.

What's the difference between a silo and a bulk tank?

Terminology varies. "Bulk tank" usually refers to the storage tank on a dairy farm. "Silo" refers to the larger storage tanks in the dairy plant. Functionally similar but silos are typically much larger (50,000–500,000 L vs farm bulk tanks of 5,000–30,000 L), with more sophisticated cooling, agitation and CIP systems.

How long can raw milk be stored before processing?

Maximum 48–72 hours from receipt is typical industry practice. Beyond this, microbial growth (especially psychrotrophic bacteria like Pseudomonas) compromises quality, even at 4°C. Most plants aim to process within 24–36 hours of receipt. Longer storage requires specific quality monitoring and may trigger downgrading of downstream products.

What is a typical reception capacity?

Depends on plant size. Small dairy (100,000 L/day): 1 reception bay, ~30,000 L/hr discharge capacity. Mid-market (500,000 L/day): 2 reception bays, ~50,000 L/hr combined. Large industrial (1M+ L/day): 4–6 bays, 100,000+ L/hr combined. Reception is typically not the production bottleneck for well-designed plants.

Further reading: John Watson publishes articles on dairy industry topics on LinkedIn. Browse all articles by John Watson on LinkedIn →

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