Can Metal Lug Caps Be Used for Highly Acidic Foods?

Can Metal Lug Caps Be Used for Highly Acidic Foods?

Challenges of Packaging Acidic Foods

In food processing and preservation, acidic environments present a significant challenge. Products such as ketchup, jam, and pickles, due to their low pH levels, place higher demands on the corrosion resistance and sealing performance of caps and containers.

If packaging materials are not properly selected, the inner layer of the cap may corrode, the liner may fail, and the food’s flavor and shelf life may be compromised. This leads many companies to ask: Can metal lug caps be safely used for highly acidic foods?

Acid Resistance Conditions and Limitations

The answer is yes, but within limits: metal lug caps can be applied to foods with pH ≥ 4.2.

The lower the pH (higher acidity), the greater the challenge for both the metal and the liner. Kamellia’s metal lug caps, combined with strict quality control processes and suitable liner designs, effectively resist typical acidic environments, maintaining sealing and preservation performance.

Applicable cases:

• Jams and fruit preserves: usually above pH 4.2, safe for stable application.
• Ketchup: classified as medium to high acidity, suitable for metal lug caps.
• Pickles: depends on fermentation conditions; if pH ≥ 4.2, safe to use.

If the food acidity is too high (pH < 4.2), long-term contact may affect the cap liner. In such cases, professional testing and evaluation are recommended.

Kamellia’s Quality Control and Material Selection

• Professional Expertise

Since its founding in 1967, Kamellia has specialized in cap manufacturing for over half a century, accumulating extensive experience in food-grade applications and providing tailored solutions for different acidic foods.

• Safety Assurance

Uses PVC materials compliant with food hygiene regulations, meeting safety standards for food contact.

• Strict Quality Control

Each production batch undergoes inspections for coating thickness, liner thickness, tensile elasticity, oil resistance, and heat resistance. Samples are retained for one year to ensure consistency and traceability.

• International Certifications

Certified under ISO 9001:2015 Quality Management System, reflecting Kamellia’s dual commitment to quality and sustainability.

Choosing the Right Cap for Your Food Products

For acidic foods such as ketchup, jam, and pickles, metal lug caps are an ideal choice, providing both sealing integrity and preservation—provided the food pH is not lower than 4.2.

If your product requires stricter preservation conditions, or if you would like to further understand the compatibility between caps and acidic foods, please contact Kamellia today. With professional expertise and international certifications, we are dedicated to creating the most reliable packaging solutions for your brand.

More Metal Lug Cap FAQ：

1      What is the Difference Between Metal Lug Cap and Regular Bottle Caps?

2      How to Choose the Right Metal Lug Cap for Your Product?

3      What Customization Options Are Available for Metal Lug Caps?

4      How to Choose the Right Metal Lug Cap for Your Product?

5      What Are the Common Applications of Metal Lug Caps?

6     What Are the Materials of Metal Lug Caps? What Are Their Advantages and Disadvantages?

7      What Products Are Metal Lug Caps Suitable For?

8      What Factors Affect the Price of Metal Lug Caps?

9      Do Lug Cap Liners Support PVC-Free and Eco-Friendly Materials?

10   Can Lug Caps Withstand High-Temperature Retort or Pasteurization?