Plant-Based Beverage

Short Soy Milk Shelf Life: Diagnose the Process Before Changing the Bag

Northeast China · Soy milk (plant-based beverage)

The Challenge

The client was running a PE+PE structure with roll-film inline filling. Shelf life fell short of target, and the expectation was to solve it by moving to a higher-barrier bag.

Sterilisation runs at a 98°C pasteurisation level, which does not kill spore-forming bacteria — the real bottleneck for shelf life.

The client wanted to keep the existing bag format and filling method, without rebuilding the line.

What We Did

  • Diagnose before changing material: shelf life was broken into three lines of enquiry — sterilisation process, packaging barrier, storage and transport conditions — to locate the actual weak link first.
  • Sample-based verification: the client sent both the product and the bag currently in use, so the comparison ran on the real content rather than on barrier figures alone.
  • Material route: a boil-resistant film as the main direction, leaving room for a later process upgrade, with coating technology explored in parallel to raise the barrier.
  • Practical format: keeping roll-film inline filling unchanged to hold the client's switching cost down.

The Result

  • Structure and process bottleneck confirmed: the issue is sterilisation intensity, not the barrier of the packaging itself.
  • The material direction has moved into sample trials, advancing on a verify-first-then-specify basis; the project is currently at the material analysis and solution confirmation stage.

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