What the rules say. Net weight means not the beans or corn or fruit; it means the food plus liquid. Food and liquid are supposed to fill as much of the can as possible, says the Department of Agriculture, so that for green beans, say, “product and packing medium occupy not less than 90 percent of the total capacity of the container.” Requirements for the food-to-liquid ratio are arcane, but as an example, the USDA requires short-cut green beans in an 8-ounce container to weigh at least 4.5 ounces, filling about 56 percent of the can and leaving 3.5 ounces of water. Chicken breast must have an average drained weight of 56 to 66 percent of the labeled weight, depending on container size.
When we asked a few companies why we found so much liquid, representatives tended to apologize without answering. “It should be about three-fourths corn and one-fourth water,” said a rep from General Mills, owner of Green Giant. “The water is in there to keep the freshness of the product.” A Hormel rep said that all of the company’s canned chunk products, including chicken, should be about 80 percent product and 20 percent water when drained gently. But the cans we opened had 54 percent chicken and 46 percent broth.
Bottom line. You’re not imagining there’s plenty of liquid in some food cans. But the amounts we found are legal, and it’s hard to fill cans much more. To get packaged food with a net weight that’s closer to the actual product weight, you can buy vacuum-packed food, or look for products that do what Chicken of the Sea did last year with tuna: It created a no-drain can with “no liquid to spill!” says a video on the company’s website.
Also look for products that clearly fill their plastic or cardboard packaging. Bypassing metal cans in favor of other packaging might also lower (though not eliminate) exposure to bisphenol A (BPA), which is found in some can linings. Some studies have linked BPA to health problems.