Why Some Food Storage Won’t Last – Double Enamel Cans

Written by The Ready Store

In our previous installment on Why Some Food Storage Products Won’t Last we covered the importance of a good can seam and how a poor seam will lead to increased levels of oxygen over time which results in food spoiling early. Today we are going to look at another element of the can, the necessity of a double sided enamel coating.

Can Diagram

There are two main reasons to use a double enameled can, first the flavor of your food is preserved by creating a layer between the steel and the food. Without the layer the food will take on the taste of the steel can over time.

The other benefit is preventing rust both internally and externally. Moisture coming in contact with metal will lead to rust which over time jeopardizes the can’s ability to create the ideal atmosphere for the food contained inside.

While double enamel cans cost more (and some companies skimp by going with a one sided enamel) you shouldn’t settle for anything less. You need to make sure that your food storage #10 cans comes with external and internal enamel coated walls so you can maximize the shelf-life of your food storage.

Updated December 2, 2011


  1. Bill Thomas wrote:

    Which companies use double enamel cans?

    December 5th, 2011 at 4:53 am
  2. Don Gordon wrote:

    You sell Mountain House & Saratoga Farms. Do both of these use the so called double enamel cans? Are you refering to paint on inside AND outside or double on inside? With proper storage, enamel on outside is not necessary unless someone excersizes poor storage location, etc. Even then, it would be noticable. MH uses a nitrogen flush along with oxogen absorbers. They also claim a 25-30 year shelf life with proper storage. I have 120 #10 cans stored in <60 degrees. I was told there would be no problems.

    December 5th, 2011 at 5:57 am
  3. Dave W. wrote:

    I stored all my food in a water/air proof tub.I know nothing can get in.A bear couldn’t get into it without the key.20 cans of food,AR-15 and 100 rounds of ammo.All locked up in a pelican 1690 Transport Case.That is just my back up plan.

    December 5th, 2011 at 6:05 am
  4. Billy Lo wrote:

    Dave W, you need more ammo in there bro.

    December 5th, 2011 at 6:22 am
  5. John wrote:

    Has anyone heard the buzz on the news about the BPA in the lining of cans? Is this something we should be nervous about with our long term storage cans?

    Does Milar bags have BPA?

    Thanks for looking into this stuff.

    December 5th, 2011 at 7:44 am
  6. Cheryl wrote:

    My son is a metallurgist for Silgan, the company that makes all the cans for DelMonte as well as Campbell and several other companies. The BPH present in any food grade can linings is only a few parts per billion. Back in the 50,s the cans had a few parts per MILLION. MUCH more BPH. There have been no proven links between that tiny amount of BPH and any illnesses, cancers, etc. regardless of what you hear in various webcasts. The research has been done, the claims are false!!

    December 5th, 2011 at 8:58 am
  7. Cheryl wrote:

    As Billy Lo said, Dave W, you need WAY more ammo than a hundred rounds! Try and see if you can’t get at least 500 packed. I have at least a thousand though they do weigh a lot.

    December 5th, 2011 at 9:01 am
  8. Renee wrote:

    We can’t eat such high salt items in freeze dried food. So instead of already made stuff, I bought ingredients to make food from The Ready Store. I then located no salt bouillon cubes and bases. Will I have trouble finding these items in a food crisis and is there anyway to make these jars store longer?

    December 5th, 2011 at 9:23 am
  9. Renee wrote:

    It’s been a long time since math class. Is that greater than 60 degrees or less than 60 degrees? If we run ourheater and humidifier through our central air for our sinuses, at 40%, does that affect the food. If so, where should we store it for the winter?

    December 5th, 2011 at 9:25 am
  10. Cheryl wrote:

    Renee, not sure if this will answer your question or not.. I live in Northern Wisconsin in an old farmhouse. My basement rarely ever gets over 60 degrees, nor drop much lower than that. It IS damp though, and I can’t run a dehumidifier. What I have been doing is getting 1-gallon food storage bags (The kind that close with twisties) and putting each can into a bag. I then fold the top over and carefully seal the bag with clear carton packing tape. I’ve been doing this for YEARS and have never had a single can show any signs of rust. Food inside the still unopened can will not be affected. It’s the temp extremes one finds by storing their food say, in the garage. THAT would make for limited shelf life and poor taste.

    December 5th, 2011 at 10:46 am
  11. Cheryl wrote:

    Renee, another thing.. Yes, things like bullion will become VERY hard, if not impossible to get in an emergency/survival situation. You should stock up as much as you are able. Also, imported things will be impossible to get. If you use many seasonings such as pepper, cinnamon, and other imported things, they will also be next to impossible to get. You may want to stock up on those things as well. Keep the containers out of direct sunlight, and in the coolest place you can. They should last several years that way

    December 5th, 2011 at 10:50 am
  12. admin wrote:

    @Bill, we do not have a list. As for our product line Mountain House and Saratoga Farms both use double enamel cans.

    @Don, double enamel means a coating on each side. As for Mountain House they no longer use nitrogen flushing, just an 02 absorber. Recent data of the past few years has shown that the 02 absorber works better than nitorgen flushing and that there is no added benefit in doing both.

    @John, the BPA numbers that are coming out are with wet foods like soup, dry foods (dehydrated and freeze-dried) do not exhibit anywhere near the degree of leaching, if it occurs at all.

    December 5th, 2011 at 10:55 am
  13. admin wrote:

    Also, a side note. Our canned drinking water has BPA free enamel lining. Again, with a liquid product such as water and soup or tuna you will get some leaching of the chemicals into the food but with dry food it will be a fraction of even that, if it shows at all.

    December 5th, 2011 at 10:58 am
  14. Carol Miller wrote:

    Use a non-working upright freezer to store items not from The Ready Store. Line the shelves w/newspaper and keep closed for about a week to absorb any residual moisture. Then you can load it up with spices, packaged goods, mixes, etc. Best to use a vacuum sealer like FoodSaver to double seal. I have used two “dead” freezers for years, both inside and outside for safe storage. If outside, remember to lock or chain to keep little ones out. Styrofoam coolers work well also for small items and they can be stacked in a corner someplace.

    December 5th, 2011 at 11:07 am
  15. Survivor wrote:

    Not a complaint – but a previous article mentioned that they insert the little ‘keep fresh’ packages to absorbe oxygen from the cans – and these little packets are full of iron oxide shavings that rust to process the oxygen. Now this article says that “Moisture coming in contact with metal will lead to rust which over time jeopardizes the can’s ability to create the ideal atmosphere for the food contained inside.” Isn’t that the same thing as the ‘stay fresh’ packers? Just askin…

    December 5th, 2011 at 11:11 am
  16. admin wrote:

    @Survivor, not sure I understand your question.

    December 5th, 2011 at 11:20 am
  17. Bebop wrote:

    I’ll quote from an earlier answer to start my reply/questions:

    admin wrote: Also, a side note. Our canned drinking water has BPA free enamel lining. Again, with a liquid product such as water and soup or tuna you will get some leaching of the chemicals into the food but with dry food it will be a fraction of even that, if it shows at all.

    December 5th, 2011 at 10:58 am

    So, here are my several questions:
    So, I guess ‘enamel’ does not mean what it once did, a “glass” (vitreous mineral) coating to a metal. So, what is the ‘enamel’ lining composed of, if not melted then deposited minerals ??? Just liquid chemicals sprayed onto the steel ??? (Not like the tin applied by heat, I think, to what we old farts call “tin cans” )
    Second question: is the ‘enamel’ applied before or after the side seams are made…ie, does the welding of the side seams destroy the enamel ? (And same for the crimped…seamed… tops ?? Does the crimping ruin the enamel ? )

    Most important…If your liquid products are in
    “BPA free” “enamel” cans, why not all products ?
    This is the most important question, thank you.
    I’ve bought from you before, and I await your answers…

    Thank you, sincerely

    December 5th, 2011 at 1:54 pm
  18. admin wrote:


    It is a FDA approved phenolic enamel which is used by major caners across the country. As for the inner portion of the can it’s coated after the seam is welded so the entire inside is protected.

    The BPA-free enamels are something the can manufacturers are working on and that is what we have been told. My guess is they are holding off on making the changes until they can do it in a cost effective manner. The technology is clearly there since a small number of companies are already doing it but it is not yet a product/process adopted by major can manufacturers yet.

    December 5th, 2011 at 4:43 pm
  19. TexasRedNeck wrote:

    Dave, you definitely need more ammo. That case has handles and wheels. 1000 rounds of 5.56 weighs about 29 pounds. Pack a spare bolt, firing pin, gas rings, extractor spring. Murphy’s law – those little nagging items will break and keep a weapon from running. Also, don’t forget some water purification device. 20 cans of food is not very useful without the water to hydrate.

    December 5th, 2011 at 9:18 pm
  20. Milt wrote:

    General Material Science info. Enamels are ceramic, which in layman’s term is “non-metallic inorganic chemistry”. The main problem in the development of proper enamel coatings for metals lies in the development of the chemical bonding of the enamel coating to the underlying metal. Constant R & D work is being done, and great promise is currently being shown in the use of composites, instead of metals as the underlying base. If only the cost of the composites decreases slightly, you’ll see a lot of composite, instead of steel/metal cans. The shipping costs could end up being the driving factor in the final development.

    December 6th, 2011 at 9:59 am
  21. Dustin wrote:

    Hi everyone,

    I’m “cheryl”s son. I work with Silgan Containers, who manufactures 50% of the steel cans in America, selling to the likes of Del Monte, Campbells, etc. I can’t say much (company proprietary info concerns) but we’re working on BPA-free coatings at the request of our customers. I’m personally not concerned about eating food from BPA-coated cans, there isn’t enough of it there to do anything IMHO.

    With regards to the article saying you need double enameled cans, I don’t buy it. Just like everything else in life, “it depends” (on what you’re putting in the can). Things that are more aggressive (tomato products, citrus products) need thicker coatings. Other things likes peaches you don’t use ANY organic coatings because Americans are used to seeing their peaches bright orange – a chemical reaction with the tin plating on the steel keeps this color. If it wasn’t touching tin (ie, if you had a polymer coating) the peaches would be a yucky grey color and people would think that they are bad. It all depends on the product…it also depends on how the can is made. There are three different types of metal can manufacturing methods and they all require different coatings.

    @Milt – I don’t understand any of what you said, doesn’t make sense to me.

    December 23rd, 2011 at 6:03 pm
  22. anunturi timisoara wrote:

    hold opinion until I look into it further. Good article , thanks and we want more! Added to FeedBurner as well…

    January 15th, 2012 at 7:28 pm
  23. McKinley wrote:

    I have a bunch of dry goods [dry milk, tang, hot cocoa powder, etc] that I want to preserve in #10 cans–where can I buy empty-ready-to-be-sealed BPA free, double coated enamel, cans?

    January 19th, 2012 at 1:26 pm
  24. Cheryl wrote:

    Right now I do not believe there are double coated BPA free cans made. As Dustin was saying above, the industry is currently working on an enamel that’s BPA Free, but as of yet, has not come up with one. At this point, all the lined cans have some (parts per billion) BPA in them.

    Back in the 50’s through the early 80’s, the BPA content in the coatings in cans was MUCH higher than now; in the parts per MILLION as opposed to parts per BILLION now. No ill effects were noted to the people eating foods from those cans all those years. BPA hasn’t been outlawed in cans for that reason.. it’s been safe all these years. BPA free enamel is still in the works; still in the development and research phases

    January 21st, 2012 at 8:47 am
  25. Anglea Prutt wrote:

    I really enjoyed reading this. It is nice to get a fresh perspective of things.

    March 10th, 2012 at 7:58 am

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