In our previous installment on Why Some Food Storage Products Won’t Last we looked into the role that 02 absorbers play in keeping your stored food not only safe but nutritious and tasty for the long haul. Today we are going to talk can seams. While it isn’t the most exciting sounding topic in food storage land it is a VERY important component to getting your food reserves to live up to their name.

First off, there are several forces working to spoil your food storage namely Humidity, Air, Light, and Temperature (HALT). A metal #10 can will clearly block light and an 02 absorber can reduce oxygen levels to neccessary levels but if the can does not have a great seal then air and moisture will enter the can over time and speed up spoilage and kill nutrition and palatability. Without a rock solid seam your average food item will go downhill fast.

In a Brigham Young University study, they examined the quality of rice after it has been canned and stored for a long period of time. They found that 1/3 of the cans they sampled had a poor seam which led to increased air and humidity levels. See the image below for examples of good and poor can seams from their study.

While the rice in this particular study did relatively well (even with bad can seams) the important point for this article is to show what a good seam looks like and the ramifications for most foods (outside of rice and a couple others that don’t need great environments) that would not fair so well when placed in a can with an inferior seam.

At The Ready Store we understand the importance of a good seam, we test our cans regularly and at the slightest seam degradation we stop production and tune the can seaming equipment to make sure it turns out the perfect seam as seen in the image below. We know our food is only as good as the seam on the can and want our product to be there for our customers when they need it most.

TIP for the DIYer: Purchase a dial/digital caliper and measure seam width and height of the top and bottom seams for consistency (cans from the manufacturer are sent to food storage companies with 1 seam already made. The food storage company fills the can with food then performs the last seal on the open end). If both are very similar it would tell you that the food storage company is doing a good job of matching the manufacturer’s seam.  If the height was significantly shorter (we are dealing with 1/1000 of an inch here) than the manufacturer’s then I would worry about overlap of the body and cover hooks, if the thickness was a lot larger than manufacturer’s (should be .058 of an inch) than I’d be worried about overall tightness. In the image at the top of this page you will see in the poor seams that they are fatter and not overlapping internally as much as they should. Another option (which destroys the can) is to cut a can in half and check the cross-section of the seams as we have in the photo of a Saratoga Farms can above this paragraph.

Unfortunately most people in the US don’t get to handle their #10 cans before purchase and those that do don’t have the training to evaluate a seam correctly. In the end, buy from someone you trust. Food storage packaging needs to create the ideal environment for the food and for that to happen the can must be sealed well.