The beginner’s step-by-step guide to shelf life and packaging

The beginner’s step-by-step guide to shelf life and packaging

Over-packaging erodes profits

Why do shelf-life testing? Insufficient packaging allows water activity in food products to rise or fall over time—causing undesirable physical changes, moisture migration, chemical degradation, and susceptibility to microbial growth. Over-packaging, on the other hand, is expensive and can erode profits. How can you figure out the exact amount of packaging your product needs? All of these issues are controlled by water activity. If you understand how water activity works, you can develop and package products that stay safe and desirable for the entirety of their shelf life—without overspending.

What exactly is shelf life?

Shelf life is the time during which a product remains desirable. Your product may exhibit some changes during shelf life, but the end of shelf life is defined as a point where the product is no longer acceptable to consumers. Unacceptable changes could be sensory characteristics, a loss of chemical stability, a change in physical properties, microbial growth, vitamin degradation, and more. 

Step 1: Identify what ends shelf life

The first step to determining shelf life is to identify what ends your product’s shelf life. There are three main factors that influence shelf life:

  • Microbial properties: mold or potentially hazardous bacteria that grow to unsafe levels in your product.
  • Chemical changes: browning, lipid oxidation, enzymatic reactions, and more
  • Physical deterioration: changes in texture, caking clumping, moisture migration, and more.

These three factors can be intrinsic within the product itself—how it’s formulated. Or they can be extrinsic—related to storage conditions, particularly the storage humidity and temperature, or the type of packaging. All three factors are connected to—and can be controlled by—water activity.

Watch the video below to see how water activity is used to predict, prevent, and control the factors that end shelf life.

Get the essentials of water activity condensed in this 20-minute webinar. You’ll learn:

-What water activity is
-How it’s different from moisture content
-Why it controls microbial growth
-How understanding water activity can help you control moisture in your product.


Shelf life, shelf-life testing, packaging
Figure 1. Water activity stability diagram (by Dr. Ted Labuza) showing the effect of water activity on modes of failure


Unlock the steps