Spring is here, and for those who need to avoid grocery store produce due to sprays and cross contamination, that means food preserving. I have done a little bit of canning, but I’m no expert: I’m here to talk about avoiding corn in canning supplies. If you have questions about how to actually do the canning safely or how to make your canned goods taste *good*, that is a question for someone else.
Avoiding Corn in Canning
Lids & Jars
The standard glass canning jars available in the grocery store are perfectly safe for a corn allergy. Rather, it’s lids are the single biggest concern for corn allergy in canning. The new Ball BPA-free lids are NOT corn free. I don’t think anyone has been able to get a detailed answer from Ball about what exactly is in the resin, but something in it is causing many corn allergics to react, and NOT just the most sensitive folks. Some are even breaking out in a rash from touching the lids. I had thought for a time I was okay with them because I was able to store non-canned food in them. Turns out that the resin in the seal was simply staying on the lid and not touching the food. Once I water-bath canned dozens of quarts of (expensive, mail-order) mandarin oranges, I discovered that when the boiling water melts the resin and creates a seal, it also infuses all of the water with corn. My non-allergic friends and family have been enjoying my delicious, now-corny mandarins all winter.
One possible option other than the Ball canning lids is Tattler reusable canning lids.
I’ve been using the Tattlers and so far, so good, but I’ve done basically two batches of applesauce so far and not much else. Updated August 2015: Yeaaahh I think I had a mild reaction to applesauce canned with the old school tattler lids. On top of that, right after I bought a bunch of them they changed their lids to be “new and improved” and have a better seal. No definitive reports on safety.
Another alternative is to use the Weck canning system. These are reported safe by several corn allergics. I haven’t tried them quite simply because they are expensive. The seals on the Weck jars are natural latex rubber, so NOT safe for a latex allergy.
I suggest you give tattler or Weck (if you aren’t allergic to corn) a careful try with one or two cans and see how it goes. If you do not tolerate either, unfortunately you’re stuck with freezing and dehydrating.
There are a couple other kinds of canning lids, but I don’t know anything about them. If you have some options and links and contact info to the companies, please comment below.
Ingredients
As always, any ingredients you use in canning need to be safe for you. Application of heat can denature some allergens for some people, but so far I haven’t heard of anyone with a corn allergy being able to eat corn just because it had been cooked enough. Here are the biggest concerns with canning:
Salt
Salt can most definitely be corny, so use something that you know is safe for you. Any safe salt should work fine instead of “canning salt.” The main reason to use canning or pickling salt is that it will not have minerals which may alter the appearance (but not taste or safety) of your canned items.
Sugar
Sugar can be cross contaminated with corn. Make sure to use something you know is safe for you.
Lemon Juice or Vinegar
Botulism requires an anaerobic (no air) environment and low acidity to grow. Adding an acid is a common way of making a low-acid food item such as a vegetable or some varieties of tomatoes safe for water-bath canning. Both pre-squeezed lemon juice and vinegar are commonly corntaminated. In the case of vinegar, it’s actually typically made *from* corn. There are vinegars that are not made from corn, though many of them are contaminated in some way. If you have a safe premade vinegar, great. Do NOT use your own homemade vinegar though, unless you have a way to be 100% sure that it is ph 4.5 or below. Similarly, the FDA’s official recommendation on lemon juice is to only use the bottled stuff because it has a standardized acidity. Of course this standardized acidity can be achieved by adding corn-derived acids, so that is no good for us. If you have a bottled lemon juice that works for you, great.
If you don’t have safe vinegar or lemon juice, probably skip these recipes and convert them to pressure canned recipes instead, which do not require a high acidity since the high heat of the pressure canner will kill all botulinum spores.
General Canning Resources
If you are new to canning, I recommend that you read up on canning safety. Even if you have some basic familiarity, you may want to review. Safety recommendations have changed in the last decade or two, so what you learned from your grandmother may not be safe. Botulism is a real concern with canned goods, even today, so it is important to follow temperature, acidity, and cook time guidelines in well-tested recipes. The below resources can teach you about canning in general, but be aware that the recommended ingredients may not be safe for you.
Corn Allergy Girl 
We were very sad when all of the Alaskan salmon my grandmother caught and canned for us was an immediate, obvious and horrible reaction. We discovered the corny Ball lids the hard way too. My mom cans a lot of jams and we have been okay with her lids “Home Discovery”. We haven’t tried any in about a year but maybe others will find that one safe too.
Oh man, what a rough way to learn that lesson! Where do you buy the Home Discovery canning lids from, Valerie? I googled and found mention of the brand but no online sellers.
Yes, it was very sad because it was the best tasting canned salmon ever and my kids loved it. Talk about easy meals if it we didn’t get corned from it! I will ask my mom where she gets the lids. She is in Canada so they may not be as easy to find in the US.
Came back to check this post to see if any updates by you or any commenters. We are visiting again at my parents and my mom has canned goods she wants to know if we can eat. She hasn’t found any more of those Home Discovery lids that we did well with. Have you ever hear of Bernardin lids and if any corn allergics have had success with them?
Hi Valerie. I searched and Bernardin is made by the same company as Ball and Kerr and became BPA free at the same time as those two brands, sadly. I suspect they would be corny for the same reason.
People are doing well with the Harvest Guard brand reusable canning lids. Unfortunately the rubber ring is latex and I finally have confirmation that I am allergic to latex. I believe that is why I cannot tolerate those lids and that it is not a corn issue. If you are not allergic to latex, that may be a good option for you.
There are some european canning lids that stll have BPA that I may look into trying out. Meanwhile I bought a freeze dryer since canning just still is too difficult for me personally with my sensitivities.
Thanks for the info. This is very helpful. I was also trying to see if you mentioned ziplocks somewhere on your page because I thought it was you who was reporting some reactions to the new ziplocks but I can’t find the discussion anywhere. This was about ten years ago. I also found we were reacting to ziplocks after having been good with them previously. Curious if anything has changed and if they are safe now?