Age Your Canned Goods
Why I now think of best-by dates as maybe-getting-interesting-by dates.
As far as I can tell, European connoisseurship in canned goods goes back about a hundred years. It was well established by 1924, when James H. Collins compiled The Story of Canned Foods. Collins noted that while the American industry—which started in the 1820s and took off during the Civil War—focused on mechanization and making locally and seasonally abundant seafood and vegetables more widely available, the European industry continued to rely on handwork and produced luxury goods for the well-off, who would age their canned sardines for several years like wine. Today, Rödel and Connetable, both more than 150 years old, are among the sardine makers that mark select cans with the fishing year and note that the contents “are already very good, but like grand cru wines, improve with age” for up to 10 years.
But the appreciation of can-aged foods wasn’t unknown in the United States. Collins recounts an informal taste test conducted by a New York grocer who rounded up old cans from a number of warehouses, put on a luncheon in which he served their contents side by side with those from new cans, and asked his guests to choose which version they preferred. Among the test foods were fourteen-year-old pea soup and beef stew, and twelve-year-old corned beef and pigs’ feet. The guests preferred the old cans “by an overwhelming majority.”
There must be many such minor treasures forgotten in kitchen cabinets and basements and emergency stashes all over the country. My own supply still being fairly young, I consulted the eminent Sacramento grocer Darrell Corti, who very kindly shared a few items from his storeroom. I compared a new can of French sardines in olive oil with 2000 and 1997 millésimes. The brands were different, and so were the size and color of the fish and the quality of the olive oils. That said, the young sardines were firm and dry and mild; the older vintages were fragile to the point of falling apart, soft and rich in the mouth, and fishier in a good way. A 2007 (70th anniversary) can of Spam was also softer than the 2012 (75th), less bouncy and less immediately and stingingly salty, though the aromas were pretty much the same. Some Corti Brothers mincemeat aged for a year under a cap of suet was delicious, its spices and alcohols seamlessly integrated. A five-year-old tin of French goose foie gras: no complaints. Two vintages of Corti Brothers bergamot marmalade: the older noticeably darker in color and surprisingly reminiscent of Moroccan preserved lemons. And 3-year-old Cougar Gold—still moist and not as sharp as open-aged cheddars—was deeper in color and flavor than the yearling version, with a touch of caramel and the crunchy crystals that are the hallmark of hard aged Goudas.
The trouble with aging canned goods is that it takes years to get results. However, we can take a hint from manufacturers, who often accelerate shelf-life tests by storing foods at high temperatures. A general rule of thumb is that the rate of chemical reactions approximately doubles with each 20-degree rise in temperature. Store foods at 40 degrees above normal—around 100 degrees—and you can get an idea of a year’s change in just three months.
But it’s possible to go further. At 120 degrees, you get a year’s worth of change in six weeks; at 140 degrees, three weeks; at 180 degrees, five days.
Of course temperatures that high are cooking temperatures, and their heat energy drives reactions that would never occur in normal storage. But if we’re interested in the evolution of canned foods, which have already been extremely cooked, then why not treat them to a little additional simmering and see what happens? (It’s safest to stay a little below the boil, to avoid building up steam pressure in the can.)
I’ve found that braising cans change the flavors and textures within, but unpredictably so. It doesn’t seem to do much for sardines, but tuna in water loses its beefiness and becomes more pleasantly fishy and also a little bitter, while tuna in oil somehow gets more meaty and less fishy. Like its aged version, can-braised Spam takes on a softness that’s especially nice when you fry the surface to a crunchy crust.
I don’t recommend cooking foods in the can as a routine thing. Cans have various linings that may gradually release unwanted chemicals into foods, and this process will also accelerate at high temperatures. But it’s a way to explore how canned foods are capable of developing.
I do hope that some restless, frontier-seeking food lovers will look past our present happy surfeit of small-batch pickles and fruit preserves and try their hands at canning age-worthy meats and fish. This could be done Appert-style in mason jars, but it’s also a chance to combine cooking with metalwork, as some French cooks have done. Jules Gouffé’s 1869 Book of Preserves simply directs the cook to solder lids on tins for a number of fish, meat, and vegetable preparations, and the 1938 edition of the Larousse Gastronomique does the same for foie gras.
And there are some things you could really only put up in metal. According to the early canning chroniclers A. W. and K. G. Bitting, in 1852, Raymond Chevallier-Appert presented to the French Society for the Encouragement of National Industry an entire sheep, already a year in the can.
Vintage head-to-tail: Now there’s inspiration for rethinking the can, and the stash-worthy.
Harold McGee writes about the science of food and cooking. He’s the author of On Food & Cooking: The Science & Lore of the Kitchen and Keys to Good Cooking, and he posts at curiouscook.com.