Butter Oil Production Line Case Study: From 30m³ Storage Tanks to Food-Grade Filling

When a food manufacturer says they need a “butter production line,” the first question should always be:

Are they producing butter from cream, producing AMF from butter, or handling liquid butter oil that is already prepared?

In this case, the customer already had liquid butter / butter oil stored in tanks.
They did not need a final concentrator, separator, or vacuum dehydration system.
What they needed was more practical: a system to transfer, heat, blend, control temperature, and fill the finished product.

So the correct project name is not “complete AMF production line.”
The correct name is:

Liquid Butter / Butter Oil Heating, Blending and Filling Line

This matters because the equipment configuration becomes much more focused.
Instead of selling the customer equipment they do not need, the line is designed around the real production problem:
stable heating, gentle blending, temperature control, and food-grade filling.

Project Overview

The customer’s line was designed for liquid butter / butter oil processing before packaging.
The main equipment included:

• 2 sets of 30m³ storage tanks
• Food-grade screw pumps
• First 1000L heating and mixing tank
• Second buffer and mixing tank
• Chiller
• Plate heat exchanger
• 4-head filling machine
• Lid placing machine
• Capping / sealing station
• Cross paddle + bottom frame agitator

The process flow is simple and clear:

30m³ Storage Tanks → Screw Pumps → 1000L Heating & Mixing Tank → Buffer & Mixing Tank → Filling Line

At the same time, the temperature control system works through:

Chiller + Plate Heat Exchanger → Jacket Temperature Control for Both Tanks

The Main Challenge: Liquid Butter Is Temperature-Sensitive

Liquid butter and butter oil look easy to handle when they are warm.
They flow well, they can be pumped, and they can be filled.
But once the temperature drops, the whole process changes.

Butter oil can become thicker, slower to transfer, and harder to fill.
Industry references describe AMF / butter oil as liquid above around 36°C and solid below around 16–17°C.
This means temperature control is not optional. It directly affects production stability.
Source: Dairy Processing Handbook

If the line is not designed correctly, the customer may face:

• Slow material transfer
• High pump load
• Product remaining inside pipelines
• Uneven blending
• Inaccurate filling
• Longer cleaning time
• Temperature variation between batches

For this reason, we designed the system as a temperature-controlled liquid butter / butter oil handling line,
not just a normal filling line.

Why We Did Not Use a Final Concentrator

At the beginning of many butter oil projects, there is one common misunderstanding:
people may think that every butter oil project needs a complete AMF production process.
That is not true.

A complete AMF-from-butter process usually includes melting, holding, concentration, and vacuum dehydration.
In standard butter-to-AMF processing, melted butter can be heated to around 60°C,
held for up to 30 minutes, then sent through final concentration and vacuum treatment before cooling to packing temperature.
Source: Dairy Processing Handbook

But this customer’s requirement was different.
The customer already had liquid butter / butter oil in storage tanks.
They did not ask us to reduce moisture, separate phases, or produce standard AMF from raw butter.

So the correct solution was:

Heating + Blending + Temperature Control + Filling

Not:

Concentration + Dehydration + AMF Refining

This made the project more practical and more cost-effective.

Recommended Process Parameters

For this type of line, the main process target is to keep the butter oil in a stable liquid condition while avoiding unnecessary overheating.

The typical packing temperature for AMF / butter oil is around 40°C,
which is also practical for smooth filling.
In this project, there was no need to heat the product to 90–95°C because the customer did not require vacuum dehydration.

Equipment Breakdown

1. 30m³ Storage Tanks

The line starts from two 30m³ storage tanks.
For liquid butter / butter oil, storage tanks should not be treated as normal liquid tanks.
They should be designed to keep the material warm and stable before transfer.

Recommended features include:

• Food-grade stainless steel contact parts
• Insulation
• Heating or temperature-maintenance design
• Bottom outlet for smooth discharge
• Sanitary valves
• Level monitoring
• Easy-clean internal structure

If the storage temperature is too low, even a good pump will struggle.
In butter oil processing, stable storage temperature is the first step to stable production.

2. Food-Grade Screw Pumps

A screw pump is a good choice for liquid butter / butter oil transfer.
Compared with a centrifugal pump, a screw pump provides gentler and more stable flow for temperature-sensitive oil-fat materials.

The screw pump should be selected based on:

• Product viscosity at working temperature
• Required transfer flow rate
• Pipeline length
• Tank height difference
• Filling line capacity
• Sanitary design requirement
• Whether the pump needs insulation or heating jacket

For better control, we recommend using a VFD-controlled food-grade screw pump.
This allows the customer to adjust feeding speed based on batch size and filling speed.

3. First 1000L Heating & Mixing Tank

The first 1000L tank is the main processing tank.
We do not recommend calling it only a “reactor” in the final proposal because the customer is not doing a strong chemical reaction.
The better name is:

First 1000L Heating & Mixing Tank

Its function is to:

• Receive liquid butter from storage tanks
• Heat and hold the material
• Add formulation ingredients
• Blend the product gently
• Prepare the material for the second tank

This tank is especially important if the customer adds antioxidants, flavors, colors, emulsifiers, or other food-grade formulation ingredients.

4. Cross Paddle + Bottom Frame Agitator

The agitator design is one of the most important parts of this case.
For this line, the customer’s tank uses:

Cross Paddle + Bottom Frame Agitator

This structure is practical for liquid butter / butter oil because it creates circulation without excessive shear.

This is not a high-speed disperser application.
The goal is not to break particles aggressively.
The goal is to keep the product uniform, warm, and stable.

In dairy fat processing, mixing should be effective but controlled.
Excessive shear may introduce air or create unwanted emulsification problems.

5. Second Buffer & Mixing Tank

The second tank works as a buffer and final temperature adjustment tank.
The recommended name is:

Second Buffer & Mixing Tank

Its role is to:

• Receive product from the first mixing tank
• Continue gentle blending
• Stabilize product temperature
• Act as a buffer before filling
• Support continuous filling operation

This tank is useful because filling lines need stable feeding.
If the product temperature or flow is unstable, filling accuracy may be affected.

6. Chiller + Plate Heat Exchanger

The chiller and plate heat exchanger are used for jacket temperature control.
In this project, they connect to both mixing tanks to help control heating and cooling.

The system supports:

• Stable product temperature
• Faster temperature adjustment
• More consistent filling condition
• Better batch repeatability
• Reduced overheating risk

For butter oil, cooling does not mean making the product cold.
The goal is to bring the material to a controlled filling temperature, usually around 40°C,
depending on the customer’s recipe and packaging requirement.

Filling and Packaging Section

The downstream line in this case includes:

• 4-head filling machine
• Lid placing machine
• Capping / sealing station
• Conveyor system

This type of line is suitable for continuous filling of small to medium containers.

Common butter oil / AMF packaging formats include:

• 1kg to 19.5kg containers
• 20–25kg carton or bag-in-box
• 185kg or larger industrial drums
• 200L drums
• IBC / tote packaging

Industry references mention that AMF can be filled into 1kg to 19.5kg containers for household or restaurant use,
while industrial use often requires drums of at least 185kg.

Should Nitrogen Flushing Be Added?

For butter oil products, nitrogen flushing is worth considering.
Oil-fat products are sensitive to oxidation.
If too much air remains in the container, the product may develop off-flavor or quality loss during storage.

Nitrogen can be used before, during, or after filling to reduce oxygen exposure.
Codex also allows inert gas flushing for airtight containers, and dairy processing references describe nitrogen headspace as a common method for AMF packaging.
Source: Codex Standard for Milkfat Products

For this line, we recommend offering nitrogen flushing as an option:

Optional Nitrogen Flushing System for Oxidation Protection

This is especially useful for customers who need longer shelf life or export packaging.

What Additives Can Be Added?

The answer depends on the customer’s final product.
If the customer is producing pure butter oil or AMF, additives must be limited and comply with food regulations.

If the customer is producing a butter oil blend, flavored butter oil, or dairy fat blend, the formula may include:

• Antioxidant
• Flavor
• Colorant
• Emulsifier
• Vegetable oil
• Stabilizer
• Other food-grade ingredients

Before finalizing the equipment design, we normally ask:

• Are the additives liquid, powder, or paste?
• Are they heat-sensitive?
• Do they need pre-dissolving?
• What is the dosing accuracy?
• Are they added manually or automatically?
• How long do they need to mix?
• Do they change product viscosity?

These details affect the feeding port, agitator speed, tank design, and cleaning method.

Food-Grade Design and Cleaning

For a food manufacturer, the equipment must be easy to clean and safe for product contact.

Recommended design details include:

• SS304 food-grade contact parts
• SS316L optional for higher requirements
• Sanitary pipes and valves
• Food-grade seals
• Polished internal surface
• CIP spray ball reserved
• Easy-drain bottom structure
• No obvious dead corners
• Insulated pipelines where needed

In real production, hygienic design is not only about compliance.
It also helps reduce cleaning time, product residue, and batch contamination risk.

Challenge, Solution and Results

Challenge

The customer needed to handle liquid butter / butter oil from large storage tanks and send it to a filling line.

The main challenges were:

• The material is temperature-sensitive
• The customer did not need final concentration equipment
• The product needed gentle mixing
• The filling line required stable feeding temperature
• The system had to be food-grade and easy to clean

Solution

Z-MIXER designed a line with:

• 2×30m³ storage tanks
• Food-grade screw pumps
• 1000L heating and mixing tank
• Second buffer and mixing tank
• Cross paddle + bottom frame agitator
• Chiller + plate heat exchanger
• 4-head filling and packing line

The system focused on the customer’s real process:
heating, blending, temperature control and filling.

Results

The final design helped the customer achieve:

• More stable material transfer
• Better temperature control
• More uniform blending
• More reliable feeding to the filling line
• Lower risk of unnecessary over-processing
• More cost-effective equipment scope
• Better matching between process needs and equipment investment

Most importantly, the line was not over-designed.
The customer did not need a final concentrator, so we did not include it.

FAQ

1. Is this a complete AMF production line?

No. This is a Liquid Butter / Butter Oil Heating, Blending and Filling Line.
It is suitable when the customer already has liquid butter / butter oil and only needs heating, blending, temperature control and filling.

2. When is a final concentrator needed?

A final concentrator is usually needed when the customer wants to produce AMF from butter or cream and must reduce moisture and non-fat solids.
If the raw material is already finished liquid butter / butter oil, it may not be needed.

3. Why use a screw pump?

A screw pump provides stable and gentle transfer for temperature-sensitive oil-fat materials.
It is better than a centrifugal pump when viscosity increases at lower temperature.

4. What agitator is used in this case?

The tank uses a cross paddle + bottom frame agitator.
This design improves circulation, blending, and bottom movement without excessive shear.

5. What filling temperature is recommended?

For many butter oil applications, around 40°C is a practical filling temperature,
but the final setting should depend on the customer’s formula, viscosity, and packaging size.

6. Can additives be added?

Yes. Depending on the product, additives such as antioxidants, flavors, colors, emulsifiers, or stabilizers can be added.
The dosing method depends on whether the additive is liquid, powder, or paste.

7. Is nitrogen flushing necessary?

It is optional but recommended for better oxidation protection, especially for longer shelf life or export packaging.

Final Recommendation for Butter Oil Manufacturers

If your factory already stores liquid butter, butter oil, or dairy fat blend in tanks,
you may not need a complete AMF production line.

What you may need is a practical system for:

• Storage transfer
• Heating
• Blending
• Temperature control
• Filling
• Packaging

Before selecting equipment, confirm these details:

• Raw material name and composition
• Working temperature
• Viscosity at working temperature
• Additives and dosing method
• Batch size or hourly capacity
• Filling container size
• Cleaning method
• Need for nitrogen flushing
• Need for insulated pipelines

The right process definition can save cost and reduce production risk.

Planning a liquid butter or butter oil production project?

Send us these details and our engineers will suggest a practical configuration:

• Raw material: liquid butter, butter oil, AMF, or dairy fat blend
• Working temperature and viscosity
• Batch size or hourly capacity
• Additives to be mixed
• Filling size: 1–20kg, 25kg carton, drum, or IBC
• Cleaning requirement: manual cleaning or CIP

At Z-MIXER, we customize food-grade heating mixing tanks, screw pump transfer systems,
temperature control systems, and filling lines for liquid butter, butter oil, and dairy fat products.

Send us your process requirements, and we can provide a process flow diagram, equipment layout, and quotation based on your actual production conditions.