The Science of Shelf Life and How to Slow It Down

How much attention do you pay to expiration dates or best-by dates? How much does this matter for your long-term food storage?

Best-by dates matter, but don’t fret.

It is possible to build an emergency food pantry with food that is safe to eat far past the traditional best-by dates using proper food storage.

Food storage intended for long-term use is generally considered low-moisture food packed in either #10 cans or in Mylar bags placed within large buckets. This type of food storage significantly extends shelf life. 

The Science of Shelf Life

Shelf life is defined in the following two ways: 

Best if used by shelf life – Length of time food retains most of its original taste and nutrition. 

Life sustaining shelf life – Length of time food preserves life, without becoming inedible. 

Most foods available in the grocery store are dated with a best if used by date that ranges from a few weeks to a few years. 

However, scientific studies have determined that, when properly stored, many foods have a life-sustaining shelf life far beyond the best if used by date. 

While it may not taste quite as fresh, it still is edible and has nutritional value.

By freeze-drying or dehydrating food, you can extend the life sustaining shelf life of many foods – especially when stored properly.

Related Read: 5 Tricks to Test If Your Food’s Gone Bad

Ways You Can Preserve Shelf Life

Knowing how to preserve food with these methods allows you to extend the shelf life significantly.

You can employ several of the same techniques we use when stocking your emergency food pantry.


You can extend the shelf life of many foods simply by freezing them. 

For instance, you can extend the shelf life of bread by wrapping it in foil or plastic wrap, placing it in a sealed container, and putting it in the freezer.

You can also freeze butter, broths, and pasta sauces.


Freezing food only works when you have electricity. Plus, freezing food merely extends the shelf life by a few months.

However, freeze-drying, which freezes and dries the food out, extends the shelf life for years.

We can freeze-dry most foods, including fruit, vegetables, and meat. 

You can DIY freeze-drying foods, but it is costly to purchase a freeze dryer. A more budget-friendly option is to buy freeze-dried foods from an emergency food supplier.


Dehydrating foods, such as wheat, rice, and beans, can extend the shelf life up to 30 years.

You can dehydrate food using an oven, a dehydrator, or even just using the sun.

Once the food is dehydrated, you need to store it safely, such as placing it in secure buckets with oxygen absorbers.

Related Read: How Long Does Dehydrated or Freeze-Dried Food Last After Opening?

Store Securely

The most crucial step in extending the shelf life of foods is to store them securely. Food needs to be stored in the right containers and in the right place.

When thinking about storing food, consider the HALT method.

  • Humidity – Avoid humid spaces.
  • Air – Seal your food in airtight containers with oxygen absorbers to keep as much air away from your food as possible.
  • Light – Avoid light. Store your food in containers, buckets, or Mylar bags, in dark spaces of the home so that it won’t be exposed to light. 
  • Temperature – The best environment to extend shelf life is a cool and dry place at temperatures between 55°F and 70°F.

Mylar bags (a type of foil bag) placed within food-grade storage buckets are the best choice. 

Use Oxygen Absorbers

bag of freeze-dried strawberries with oxygen absorber

You need to use oxygen absorbers when you store dry food in sealed containers, such as mylar bags and sealed plastic storage buckets. 

Oxygen absorbers are little packets of iron powder packaged in a material that keeps the iron in but allows oxygen and moisture to enter and be absorbed. The iron absorbs the oxygen causing the iron to rust. As it rusts, or oxidizes, it absorbs any oxygen that may be present. This helps keep the food safe for extended periods of time.

Can Foods

You can also extend the shelf life of food by processing and canning food using a pressure canner.

Typically, canning foods will extend the shelf life to one year, but it may last longer depending on how you process the food.


If you want to extend the shelf life of fresh herbs, try pureeing them and freezing them.

Here is a guide from Life Made Simple Bakes.

  • Prep - Rinse herbs and pat dry. Chop as desired.
  • Tray - Place herbs in an ice cube tray; silicone ones work best. Fill each well with water, just enough to completely cover the herbs. Press the herbs into the water so they are fully submerged.
  • Freeze - Place the ice cube tray in the freezer and freeze for 3-4 hours.
  • Package - Remove the cubes from the tray and place them in Ziplock bags labeled with each type of herb. Freeze for months.

How Emergency Essentials Extends Shelf Life

The long shelf life of Emergency Essentials food products comes from our multi-layer approach to preparation and packaging

Our foods are:

  • Freeze-dried or dehydrated – a preparation process that removes moisture to keep food from spoiling
  • Sealed airtight with iron-based oxygen absorbers
  • Stored in special heavy-duty containers that protect against pests, water, and the elements
  • Many are kitted in four-layer zipper packs

Our oxygen absorbers:

  • Naturally extend shelf life by removing oxygen
  • Sustain freshness and quality of product
  • Prevent growth of harmful molds and microorganisms
  • Prevent discoloration and deterioration of the food product

The quality and taste of most unopened Emergency Essentials products will last up to 30 years. 

However, this can vary based on food storage conditions and ingredients. For example, products such as eggs and bread mixes with real dairy ingredients or small amounts of oil may have a shorter shelf life (5 to 10 years). 

Home storage conditions may also affect shelf life. For instance, extreme temperatures will deteriorate quality and shelf life. We recommend storing products in a cool and dry place at temperatures between 55℉ and 70℉ to achieve optimal shelf life.

Invest in Shelf Stable Foods

emergency food eggs and has browns

While it is important to know how to extend the shelf life of food yourself, it is wiser to go ahead and stock up on foods that are already designed to last for years.

Emergency Essentials is proud to offer quality long-term food kits in #10 cans and water-resistant buckets, with a shelf life of up to 25 years. Our buckets contain food that has been sealed safely in heavy-duty four-layer pouches. Light, moisture, and rodents aren’t going to get into this food.

Additionally, Emergency Essentials offers shelf-stable MREs with a shelf life of up to 3 years.

We offer a variety of long-term emergency food kits, veggies, fruits, soups, and stews, as well as complete kits for 1 month, 3 months, and longer.

With these on your shelf, you never have to worry about having safe food in an emergency.

Dehydrated foodFreeze dried foodOxygen absorberShelf life

1 comment

Janalee Hoopes

Janalee Hoopes

I love your products and am secure that they are prepared right and will last. I love all the helpful advise that you give us about things also. I know I can trust you. I am a big canner and food preparer and have used your advise and others since a young married lady to prepare, can and store my food. Thanks so much for all you do to help people get prepared. Please keep it up you are deeply appreciated and needed in this world that is turmoil.

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