Essential Guide for Food Manufacturers: Steam Tray Materials, Durability, and Heating Efficiency

Table of Contents

1. Aluminum Trays vs. Stainless Steel Steam Trays: Which Material Is Best for Food Factories?

2. Why Do Steam Trays Dent or Deform? Three Common Causes and How to Fix Them

3. Do Hole Patterns Really Affect Steaming? The Impact Can Be Big Enough to Ruin a Whole Batch

4. Hard to Clean Steam Trays? Food Companies Often Overlook These Three Areas

5. Steam Trays May Seem Minor, but They Play a Critical Role in Product Quality

In food factories, central kitchens, and chain restaurant production environments, steam trays may look like simple accessories, but they significantly influence steaming efficiency, steam distribution, product expansion, and overall food safety.
Whether you produce steamed buns, mantou, xiaolongbao, dim sum, ready-to-eat frozen foods, or large-batch products for retail channels, the tray material, hole configuration, and thickness are key factors that determine the consistency and quality of your final products.

1. Aluminum Trays vs. Stainless Steel Steam Trays: Which Material Is Better for Food Factories?

The material of a steam tray directly affects its durability, heat conductivity, food safety performance, and overall service life. Koten Machinery has prepared a quick comparison guide to help manufacturers identify which tray material best suits their production needs.

Criteria	Aluminum Trays	Stainless Steel Steam Trays
Durability (Resistance to Damage)	Prone to denting, deformation, and scratches; requires frequent replacement	Highly heat-resistant, maintains shape, long service life
Food Safety (Audit Compliance)	Easily oxidizes, susceptible to detergent corrosion; higher food safety risk	Meets food-contact-grade standards; low bacterial retention; compliant with factory audits
Ease of Cleaning (Tendency to Accumulate Residue)	Edges accumulate residue easily; darkens over time	Smooth surface, easy to clean, low bacterial retention

When businesses shift from occasional steaming to high-frequency daily production, the durability of steam trays becomes a major cost factor. Aluminum trays tend to deform and oxidize under long-term heat, pressure, and cleaning, whereas stainless steel trays maintain structural stability and food safety—resulting in a more reliable and worry-free production line.

2. Why Do Steam Trays Dent or Deform? Three Common Causes and How to Improve Them

Deformation of steam trays is one of the most common issues in food factories, especially in high-frequency steaming operations.

It is not a matter of bad luck — deformation usually results from the accumulation of the following factors:

1. Uneven Load and Concentrated Weight

Typical operating issues include:

• Overloading the tray with too many products

• Placing most of the weight on a single corner or area

• Stacking multiple steamers in a way that creates uneven pressure

These conditions can cause the center of the tray to sink and the four corners to lift or warp.

2. Incorrect Cleaning Methods

For many trays, deformation is caused not by steaming, but by improper cleaning procedures.

Common incorrect cleaning practices include:

• Rinsing a hot tray with cold water → rapid expansion and contraction leading to warping

• Scrubbing aggressively with metal brushes → surface scratches and accelerated corrosion

• Using strong alkaline or industrial detergents → chemical attack on the metal surface

3. Inadequate Material Quality or Thickness

Many low-cost steam trays suffer from issues such as:

• Metal thickness that is too thin

• Insufficient weld strength at joints

• Poor surface finishing and treatment

Over time, these weaknesses naturally lead to deformation under daily production use.

How to Prevent Steam Tray Deformation

✔ Choose trays with a thickness of ≥ 1.0 mm

✔ Ensure an even loading pattern and stacking method

✔ Avoid exposing hot trays directly to cold water during cleaning

✔ Use food-grade cleaning chemicals

✔ Regularly inspect tray flatness and weld integrity

“Koten stainless steel steam trays are built for durability and stable steam distribution, making them the preferred specification for many food manufacturers.”

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3. Do Steam Tray Hole Patterns Really Affect Steaming? Yes — Enough to Ruin an Entire Batch

Many operators assume that steam will “naturally pass through the tray,” but in reality:

The size, spacing, and arrangement of the holes determine whether steam can rise evenly.
When the hole pattern is incorrect, common issues include:

1. Holes Too Small → Insufficient Steam Flow

・Poor expansion
・Longer steaming time
・Surface cracking

2. Holes Too Large → Steam Impact Is Too Strong

・Bottom indentations
・Surface breakage
・Loose or uneven internal structure

3. Uneven Hole Distribution → Inconsistent Steaming Within the Same Tray

・Center rises higher than the edges
・Uneven height across products

The problem is not the recipe — it’s uneven steam circulation.

4. Different Products Require Different Hole Configurations

Food Type	Recommended Hole Pattern
Steamed Buns / Mantou	Medium-sized holes, evenly distributed
Xiaolongbao / Soup Dumplings	Larger holes to reduce concentrated steam impact
Frozen Prepared Foods	Dense hole pattern for higher steam penetration

Koten Machinery offers multiple steam tray specifications and can recommend optimal hole designs based on your product characteristics.

4. Why Steam Trays Still Look “Clean” but Fail Hygiene Standards — The 3 Most Overlooked Areas

1. Residue Around the Hole Edges Is the Most Commonly Overlooked

Grease and dough particles often remain trapped along the inner edges of the perforations. If not thoroughly brushed, these residues accumulate and become bacterial hotspots. They are not easily visible, but over time they significantly increase food safety risks.

2. Build-up on the Underside of the Tray Is the Biggest Blind Spot

Most staff clean only the top surface while neglecting the underside, where starch deposits, condensation scale, and grease residue accumulate. If not removed, these layers can rapidly support bacterial growth in hot and humid environments.

3. Weld Points and Corners Trap the Most Contamination

Weld joints, folded corners, and small scratches are common accumulation points for residue. Aluminum trays may even develop dark spots due to corrosion. Without regular inspection and cleaning, these locations often become the root cause of hygiene issues.

The biggest risk in steam tray hygiene is often not “failing to clean it,” but “thinking it has been cleaned.” If the hole edges, tray underside, and weld corners are not properly treated, the tray may look clean on the surface but still harbor bacteria in high-temperature, high-humidity environments.

5. Steam Trays May Look Like a Minor Detail, But They Play a Major Role in Product Quality

From material selection to hole pattern design and even overlooked cleaning blind spots, steam trays play a far more important role in large-scale food production than most people realize. Heat transfer efficiency, steam circulation, load-bearing strength, and hygiene control — if any one of these factors is not properly managed, it can result in uneven expansion, surface deformation, incomplete steaming, or even food safety risks.

With 40 years of expertise in steam equipment, Koten Machinery understands every detail that food factories, central kitchens, and chain restaurants face in steaming and preparation workflows. We offer a wide range of professional stainless steel steam trays and steam equipment, and can recommend the most suitable configurations based on your product characteristics, production needs, and cleaning procedures.

Frequently Asked Questions (FAQ)

Q1: What should food factories prioritize when selecting steam trays?
The most critical factors are durability and steam penetration efficiency. Material type, hole pattern, and load-bearing strength directly affect product expansion, steaming uniformity, and equipment lifespan. Beyond price, long-term production stability is the true priority.

Q2: Why are stainless steel steam trays more suitable for food manufacturers than aluminum trays?
Stainless steel withstands high temperatures, resists deformation, and tolerates frequent cleaning—ideal for heavy-duty industrial use. Aluminum trays are lighter and heat quickly, but they dent and oxidize easily, resulting in higher long-term costs and increased food safety risks.

Q3: Does hole size really affect steaming performance?
Yes. The size and distribution of holes determine how evenly steam can pass through, impacting expansion, appearance, and steaming time. Different food types (buns, mantou, pastries, prepared foods) require different hole configurations for optimal results.

Q4: What areas are most commonly overlooked during steam tray cleaning?
Typically: the edges of perforations, the underside of the tray, and weld points or corners. These areas often accumulate grease and starch residues and should be included in a standardized cleaning routine with regular inspections.

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The information in this article is for reference only. For actual models and applicable functions, please refer to the specifications provided by Koten Machinery.

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