Shelf-life varies, depending on storage and food conditions. Typically you can see an indicated range for shelf-life. Rice is classified as 15-30 years, for example, and some sources estimate 10-15 years. Usually, this disparity in time keeping is an indication of the nutritional value of the food. For example, the nutrients in the rice will begin to break down after 10 to 15 years. The rice is still healthy to eat under the right conditions for 30 or more years, however, it may have lost much of the nutrients.
Dry products will keep their expiration date well past when they are packaged dry and oxygen is removed from the box. It involves repackaging products in sealed containers or mylar bags and removing all oxygen using oxygen absorbers or a vacuum pump. Most people use their vacuum machines of the sort foodsaver to extract air; seal the food in a tight vacuum bag; then put the bags in a larger Mylar bag with oxygen absorbers.
Once the vacuum is sealed, the food remains until you have enough to fill the Mylar container. It is a safe approach to use when buying small quantities at a time, however, it is safer to pack an oxygen absorber in Mylar. The sealing mechanism will be discussed later.
Until filling, place the bag in a bucket or other suitable food safe container when sealing food in large Mylar bags, such as the 3-6 gallon sizes. The bag will need sides help to fill and store.
How To Use Oxygen Absorbers The Right Way
For Mylar bags it is possible to use oxygen absorbers, glass jars with a sealing gasket on the lid, and PETE plastic bottles with gasket style lids. For the oxygen absorbers to do their job, the jar needs to close fully.
Oxygen absorbers are stronger than most vacuum machines at extracting oxygen, however, they do not have the visual proof that many people expect. This is because air is just 20 per cent oxygen, and after the oxygen is consumed the nitrogen and other components remain. Most times after a few hours you’ll see the Mylar bag expanding around the food, but don’t be surprised if it doesn’t. The oxygen absorbers will do their job as long as the container is sealed.
Repeat until the food is packed and you are able to seal it, to open the oxygen absorber box. After opening, remove the amount you’ll be using within the next 30 minutes, secure the remaining oxygen absorbers in a glass jar or sealed vacuum bag. DO NOT open a single foil lined with an absorber!
Packing Dry Foods In Mylar Bags With Oxygen Absorbers
Follow these steps to safely pack dry foods:
- Pack foods well within their useful life, before their expiration date. Make sure they are completely dry.
- Choose the size of Mylar storage bag you will use. If you are using bags larger than 1 gallon, place them in a bucket for support.
- Clip a tiny corner or slit into the food packaging or remove it. This allows oxygen to be pulled from inside the packaging.
- Place the food in the bag. Do not overfill. Leave room for sealing.
- Check the inside lip of the bag for small food particles that can interfere with the seal. Clean the inside of the bag with a dry cloth, if needed.
- Add oxygen absorbers on the top of the food in the Mylar bag. DO NOT OPEN the individual foil packed absorber, the contents are not edible.
- Seal the Mylar with an impulse sealer for best results. If you are using an iron, check the seal thoroughly to be sure it is completely sealed. Label the bags with the contents, date sealed and a use by date.
- If using buckets, seal the bucket with a lid and gasket. Store the sealed bags or buckets in a cool, dark and dry place. Place them off the floor, elevated on a shelf to allow air circulation around and under the buckets or bags.
- Rotate foods, using within their storage shelf life.
Suitable Foods for Drying and Long Term Storage
Almost every food can be stored under the right conditions. Meats and vegetables can be canned, dried, freeze-dried, pickled, or cured.
Here is a list of foods suitable for dry storage, along with how long they will keep sealed in Mylar with oxygen absorbers and stored under good conditions:
- Whole hard grains such as Buckwheat, Dry Corn, Kamut, Hard Red Wheat, Soft White Wheat, Millet, Durum wheat, and Spelt keep for 10 years or more.
- Soft grains such as oats, barley, quinoa, and rye. Stored whole, these grains will last 8 years or more.
- White Rice keeps for 10 – 30 years stored under proper conditions. Use brown rice within 2-5 years. Brown rice contains oils which can go rancid.
- Corn keeps for up to 30 years or longer when stored whole. Cornmeal is good for 5 to 10 years.
- Dried potato slices, dices and flakes keep for up to 30 years, but may yellow a bit over time.
- Professionally dehydrated vegetables keep for 10 to 20 years, and freeze-dried fruits and vegetables for up to 25 years. Use home dehydrated foods within 2 to 5 years. Moist fruits such as raisins are not suitable for sealing.
- Sugar keeps indefinitely without an oxygen absorber or vacuum. Keep it dry, however or you’ll have a hard lump.
- Pasta keeps for 20 to 30 years.
- Powdered milk keeps for up to 20 years.
- Dried beans such as pinto beans, kidney beans, lentils, black eye peas, lima beans, and other dried beans keep for 10 to 30 years or more. Beans keep well, but require longer to cook as they age. Older dried beans cook well in a pressure cooker.
- Flour, cornmeal, and baking mixes, 5 to 10 years
How Many Oxygen Absorbers To Use? What Size?
Oxygen absorbers come in various sizes shown by the amount of oxygen CC’s they are going to consume. Volume guidelines once again come in ranges, as certain foods have more oxygen-containing spaces around them. Densely packed rice harbors less oxygen than pasta, which is loosely packed and has gaps flowing through. With your bag size, use the prescribed cc’s, use the limit with porous and loosely packed products.
For 1 to 2 quart glass jars and mylar bags, use 100 to 300 cc’s, depending on the food density. Gallon containers need 300 to 500 cc’s. For 5 to 6 gallon buckets, lined with Mylar, use 1500 to 2000 cc’s.
If the prescription is for 1000 cc of oxygen absorbers, one 1000 cc absorber may be used, two 500 cc absorbers, four 300 cc absorbers or any combination of up to 1000 cc or more. Remember that when you use 300 cc absorbers, three will only give you 900 cc, so you need to add a fourth, even though you are going beyond the minimum required.
So What Are The Right Conditions? Storage Life Depends On Four Variables:
- Temperature: Heat is your enemy. Foods break down faster at higher temperatures. Store your long-term food products below 75°F/24°C whenever possible. If you must store foods at higher temperatures, rotate them more often to ensure nutritional quality.
- Moisture: Foods must be completely dry before packing and don’t package them on extremely humid or rainy days. If moisture levels exceed 10% inside the air-tight packaging, foods can spoil.
- Light: Mylar bags do an excellent job of keeping out light, but foods stored in clear PETE bottles or glass jars need to be stored in a dark room or cupboard.
- Insects and Rodents: Freezing products for a day or two then allowing them to warm again before sealing kills insects and eggs that may be present. Whenever possible, store sealed packages in rodent proof containers such as food safe metal cans. Empty popcorn tins do a good job of excluding rodents. Watch your storage areas for signs of rodent droppings and act quickly if you suspect an infestation.
Signs of Spoilage
Please inspect the food before and after opening for signs of spoilage. Check for bloated bags or canisters before opening. If a Mylar bag is like a balloon blown up, discard it without opening. This can be caused by too much moisture in the food before sealing.
After opening, check for signs of some kind of mold or spoilage. Some foods like rice, dried potatoes and grains can yellow slightly over time and can still be consumed safely. Dramatic color changes can point to spoilage. Donate the sniff test to food as well. The off odor is a sign of spoilage, too.
Some of the most critical laws of long-term food storage is understanding and changing the shelf life of your products so that you always have a fresh supply. It doesn’t mean you will waste food, rather, recycle your oldest grocery stores into current use and bundle new long-term storage purchases.