Prudent Food Storage

The wise store up choice food and olive oil, but fools gulp theirs down. - Proverbs 21:20

Section 2 Common Storage Foods
E. Fats and Oils



E. FATS AND OILS

All oils are fats, but not all fats are oils. They are similar to each other in their chemical makeup, but what makes one an oil and another a fat is the percentage of hydrogen saturation in the fatty acids of which they are composed. The fats which are available to us for culinary purposes are actually mixtures of differing fatty acids so for practical purposes we'll say saturated fats are solid at room temperature (70°F, 21°C) and the unsaturated fats we call oils are liquid at room temperature. For dietary and nutrition purposes fats are generally classified as saturated, monounsaturated and polyunsaturated, which is a further refinement of the amount of saturation of the particular compositions of fatty acids in the fats.


E.1 BUYING AND STORING OILS AND FATS

There is a problem with storing oils and fats for the long term and that is they want to go rancid. Rancid fats have been implicated in increased rates of heart disease, arteriosclerosis and are carcinogenic (cancer causing) so are best avoided whenever possible.


Oxygen is eight times more soluble in fat than in water and it is the oxidation resulting from this exposure that is the primary cause of rancidity. The less saturated a fat is, the faster it will go off. This may not, at first, be readily apparent because vegetable oils have to become several times more rancid than animal fats before our noses can easily detect it. An extreme example of rancidity is the linseed oil (flaxseed) that we use as a wood finish and a base for oil paints. In a matter of hours the oil oxidizes into a solid polymer. This is very desirable for wood and paint, very undesirable for food.


Because of this difficulty in storing fats and oils for any long period of time many books and articles on the subject of food storage make only passing mention of them, if they say anything at all. This is unfortunate because fat contains nine calories to the gram compared to the four calories contained by either carbohydrates or protein. This makes fat a valuable source of concentrated calories that could be of real importance if faced with a diet consisting largely of unrefined grains and legumes. For small children, infants, nursing mothers, and the elderly, they may not be able to consume the volume of food that would be necessary in the course of a day to get all of the calories they would need to avoid weight loss and possible malnutrition. Additionally, fats play an important role in our perception of taste and texture and their absence would make many foods more difficult to prepare and consume. Furthermore, a small amount of dietary fat is necessary for our bodies to properly absorb fat soluble vitamins like A,D,E and K.


Long term storage of fats may be problematical, but it is not impossible. There are some general rules you can follow to get the most life out of your stored cooking oils and fats.


  1. Exposure to oxygen, light and heat are the greatest factors to rancidity. If you can, refrigerate your stored oil, particularly after it's been opened. If possible, buy your oils in opaque, airtight containers. If you purchase it in plastic, particularly clear plastic, then transfer it to a gas impermeable glass or metal container that can be sealed airtight. If you have a means of doing so, vacuum sealing the storage container is an excellent idea as it removes most of the air remaining inside, taking much of the oxygen with it. Transparent glass and plastic containers should be stored in the dark, such as in a box or cabinet. Regardless of the storage container, it should be stored at as cool a temperature as possible and rotated as fast as is practical. All other considerations being equal, oils and fats with preservatives will have a greater shelf life than those without, provided they are fresh when purchased.

  2. Unless they have been specially treated, most unopened cooking oils have a shelf life of about a year to a year and a half, depending upon the above conditions. Some specialty oils such as sesame and flax seed have shorter usable lives. If you don't use a lot, try to not buy your fats in big containers. This way you won't be exposing a large quantity to the air after opening, to grow old and possibly rancid, before you can use it all up. Once opened, it is an excellent idea to refrigerate cooking fats. If it turns cloudy or solid, the fat is still perfectly usable and will return to its normal liquid, clear state after it has warmed to room temperature. Left at room temperatures, opened bottles of cooking oils can begin to rancid in anywhere from a week to a couple of months, though it may take several more months to reach such a point of rancidity that it can be noticeably smelled.

  3. Although darker colored oils have more flavor than paler colored, the agents that contribute to that flavor and color also contribute to faster rancidity. For maximum shelf life buy paler colored oils.



Updated: 9/18/96; 4/16/97; 7/21/97; 10/20/97; 9/15/98; 11/02/99; 12/01/03


Copyright © 1996, 1997, 1998, 1999, 2003. Alan T. Hagan. All rights reserved.


Excluding contributions attributed to specific individuals or organizations all material in this work is copyrighted to Alan T. Hagan with all rights reserved. This work may be copied and distributed for free as long as the entire text, mine and the contributor's names and this copyright notice remain intact, unless my prior express permission has been obtained. This FAQ may not be distributed for financial gain, included in commercial collections or compilations, or included as a part of the content of any web site without prior, express permission from the author.


DISCLAIMER: Safe and effective food storage requires attention to detail, proper equipment and ingredients. The author makes no warranties and assumes no responsibility for errors or omissions in this text, or damages resulting from the use or misuse of information contained herein. This FAQ is not intended for, nor should it be used in, any commercial food applications.


Placement of or access to this work on this or any other site does not necessarily mean the author espouses or adopts any political, philosophical or metaphysical concepts that may also be expressed wherever this work appears.



Table of Contents


Acknowledgements & Foreword


Section 1 - Shelf Lives


  1. Time, Temperature, Moisture, Oxygen and Light

Section 2 - Foods


  1. Common Storage Foods

A. Grains & legumes


  1. Grains & Grain Products
  2. Legumes
  3. Availability of Grains and Legumes
  4. Storing Grains and Legumes

B. Dairy Products


  1. Dry Milks
  2. Canned Fluid Milks and Creams
  3. Butter
  4. Cheese

C. Eggs


  1. Dry Eggs

D. Sugar, Honey and Other Sweeteners


  1. Granulated Sugars
  2. Honey
  3. Cane Syrups
  4. Corn Syrup
  5. Maple Syrup

E. Fats and Oils


  1. Buying & Storing Oils and Fats
  2. Extending Shelf Life By Adding Anti-Oxidants

F. Cooking Adjuncts


  1. Baking Powder
  2. Baking Soda
  3. Herbs & Spices
  4. Salt
  5. Vinegar
  6. Yeast

G. Infant Formula


  1. Alternatives to Breastfeeding
  2. Selecting and Feeding An Infant Formula
  3. Storing Infant Formulas and Baby Foods

H. MREs - Meals, Ready to Eat


  1. U.S. Military MREs
  2. U.S. Civilian MREs
  3. British/Canadian MREs
  4. Other Self-Heating Ready To Eat Type Products

I. Ration Bars


  1. Ration Bars

Section 3 - Specific Equipment Questions


A. Storage Containers


  1. What is Food Grade Packaging?
  2. Plastic Packaging
  3. Metal Cans
  4. Glass Jars
  5. Mylar Bags
  6. Reusing or Recycling Packaging

B. CO2 and Nitrogen


  1. Dry Ice
  2. Compressed Nitrogen

C. Vacuum Sealing


  1. Vacuum Sealing Considerations

D. Freeze Treating


  1. Freeze Treating

E. Oxygen Absorbers


  1. What Is an Oxygen Absorber?
  2. How Are Oxygen Absorbers Used?

F. Moisture in Packaging and Food Storage


  1. Why Moisture is Important
  2. What Is A Desiccant?
  3. Types of Desiccants
  4. How Do I Use Desiccants?
  5. Where Do I Find Desiccants?

G. Diatomaceous Earth


  1. What is Diatomaceous Earth?
  2. Where Do I Find DE and What Type Should I Buy?
  3. How Do I Use DE in Food Storage?

Section 4 - Spoilage


A. Insect Infestations


  1. Pests of Stored Grains, Legumes and Dry Foodstuffs
  2. Control of Insect Infestations

B. Molds in Foods


  1. Minimizing Molds
  2. Molds in Canned Goods
  3. Molds in Grains and Legumes

C. Bacterial Spoilage


  1. Botulism

D. Enzymatic Action in Food Spoilage


  1. Enzymatic Action

Section 5 - Shelf Lives


A. Food Product Dates


  1. "Best Used By", "Use By" and Other Food Product Dates

B. Closed Dating


  1. Closed Dating Codes Used by Some Food Manufacturers

C. Shelf Lives


  1. Shelf Lives of Some Common Storage Foods

Section 6 - Resources


A. Books


  1. Books

B. Pamphlets


  1. Pamphlets

C. Electronic-online


  1. Information sources
  2. Software sources

D. Organizations


  1. The Church of Jesus Christ of Latter Day Saints - LDS Family Cannery Guidelines

E. Food and Equipment Suppliers


  1. Mail Ordering Storage Foods What You Should Know
  2. Addresses of Suppliers

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