Estimated reading time: 7 minutes
Best for: Packaged-food producers, commercial kitchens, bakeries, refrigerated-food producers, and frozen-food manufacturers
What You’ll Learn
- What shelf life actually means
- The difference between food safety and food quality
- Factors that determine shelf life
- How small producers can establish a reasonable shelf-life testing program
- Why packaging, temperature, and water activity can dramatically affect shelf life
What Is Shelf Life?
Shelf life is the period during which a food product remains acceptable under specified storage conditions.
But there are really two different questions:
Is the food safe?
and
Is the food still good?
Those aren’t necessarily the same thing.
Quality can decline because of changes in flavor, texture, aroma, appearance, moisture, or oxidation without the food necessarily becoming unsafe.
Conversely, dangerous microbial growth isn’t always something you can see, smell, or taste.
That’s why shelf-life decisions need to consider both food safety and product quality.
Why It Matters
Shelf life affects nearly every part of a food business:
- Production scheduling
- Inventory
- Distribution
- Wholesale opportunities
- Retail relationships
- Food waste
- Customer satisfaction
- Food safety
A product with a seven-day refrigerated life has a very different distribution opportunity than one that remains acceptable for 60 days.
Extending shelf life can therefore have enormous business value — but only when it is done safely.
What Determines Shelf Life?
There isn’t one standard shelf life for baked goods, sauces, snacks, refrigerated meals, or other foods.
Shelf life depends on the specific product.
Important factors include:
Ingredients
Sugar, salt, acids, fats, preservatives, dairy, eggs, fresh produce, and other ingredients can affect stability differently.
Moisture and Water Activity
Two products can contain similar amounts of water but have very different abilities to support microbial growth.
This is why water activity (Aw) can be more useful than simply asking whether a product feels moist or dry.
Water activity is particularly important when determining whether certain products can safely be stored at room temperature.
pH
Acidity affects the ability of many microorganisms to grow.
For some products, pH is a critical food-safety control.
Processing
Baking, cooking, drying, freezing, pasteurization, and other processes can dramatically affect shelf life.
Packaging
Packaging can protect food from:
- Moisture
- Oxygen
- Light
- Contamination
- Physical damage
A heat-sealed package may behave very differently from an open container.
Storage Temperature
Temperature can be one of the biggest shelf-life variables.
Refrigerated, frozen, and room-temperature versions of the same product can have dramatically different shelf lives.
FDA recommends keeping refrigerators at or below 40°F and freezers at 0°F.
Best-By Doesn’t Automatically Mean Unsafe
Date labels frequently cause confusion.
Except for infant formula, federal regulations generally do not require product dating, and USDA explains that commonly used date labels generally relate to product quality rather than automatically indicating that a product becomes unsafe on that date.
For producers, however, that doesn’t mean dates should simply be guessed.
Your date should be supported by knowledge of your product, processing method, packaging, storage conditions, and appropriate testing.
State requirements can also apply.
A Practical Shelf-Life Testing Process
For a small producer, start with controlled testing.
1. Define the product
Document the exact recipe and production process.
Shelf-life testing isn’t very useful if the recipe or process constantly changes.
2. Define storage conditions
Determine how the product will actually be sold:
Room temperature
Refrigerated
Frozen
Test under realistic conditions.
3. Produce a normal batch
Use your normal production procedures and packaging.
Record the production lot.
4. Store multiple samples
You need enough samples to evaluate the product at several points during its expected shelf life.
5. Establish testing intervals
For example, a shelf-stable product being evaluated for 90 days might be examined at:
Day 0
Day 15
Day 30
Day 45
Day 60
Day 75
Day 90
The appropriate intervals depend on the product.
6. Evaluate quality
At each interval evaluate characteristics such as:
- Appearance
- Aroma
- Flavor
- Texture
- Package condition
- Moisture changes
- Rancidity
- Mold or other visible spoilage
Record the results instead of relying on memory.
7. Perform appropriate safety testing
For products where microbial safety or shelf stability is uncertain, sensory evaluation isn’t enough.
Depending on the product, testing may include:
- Water activity
- pH
- Microbiological testing
- Challenge studies
A qualified food laboratory or food-safety professional can help determine what testing is appropriate.
Build in a Safety Margin
Suppose testing shows that product quality consistently becomes unacceptable around 75 days.
That doesn’t necessarily mean you should put a 75-day best-by date on the package.
Commercial products experience temperature changes, transportation, handling, storage differences, and normal production variation.
A reasonable shelf life should account for those realities.
Common Mistakes
Copying a competitor’s shelf life. Their formulation, process, packaging, and testing may be completely different.
Relying only on appearance or smell. Foodborne pathogens aren’t necessarily detectable by sensory evaluation.
Changing the recipe after testing. A significant formulation or processing change may invalidate previous shelf-life conclusions.
Ignoring packaging. Changing the package can change shelf life.
Testing only one sample. One package doesn’t establish a reliable pattern.
Assuming freezing kills everything. Proper freezing prevents bacterial growth while frozen, but FDA notes that freezing does not kill most bacteria.
Best Practices
Document your formulation.
Standardize the production process.
Record production lots.
Define storage conditions.
Use consistent packaging.
Maintain shelf-life testing records.
Consider pH and water activity where relevant.
Use qualified laboratory testing when food safety cannot reasonably be established through your existing process controls.
Reevaluate shelf life when significant ingredients, processes, packaging, or storage conditions change.
Software Tips
Shelf-life management can be connected directly to production lots.
If a product has an established 45-day shelf life and a batch is produced on August 1, the system can calculate the appropriate best-by date automatically.
That information can then follow the lot through inventory and sales.
This also allows reports to identify inventory approaching its best-by date so it can be sold, discounted, donated when appropriate, or otherwise addressed before becoming waste.
Questions We Hear Every Week
Can I just use the shelf life of a similar product?
Use similar products as background information, not proof of your own shelf life.
Do I need a laboratory?
Not necessarily for every quality determination, but some products require technical testing to establish safety. When shelf stability is uncertain, professional testing is money well spent.
What’s the difference between shelf life and expiration date?
Shelf life describes how long the product maintains acceptable characteristics under defined conditions. The date printed on the package communicates a particular date to the customer.
Does freezing make food last forever?
At 0°F, properly handled frozen food can remain safe for very long periods, but quality still deteriorates over time.
Related Guides
- Water Activity
- Inventory Management
- Batch & Lot Tracing
- Food Safety
Final Thoughts
Don’t guess at shelf life.
Start with the product formulation, understand the factors that control its safety and quality, test the actual packaged product under realistic conditions, and document what happens.
For many small food producers, understanding shelf life can also open new opportunities for wholesale distribution and larger production runs.