Ham scramble: Southern delicacy companies struggle to replace methyl bromide
By Lindsey Konkel
Environmental Health News
October 22, 2014
Mahogany and marbled, Sam Edwards’ thinly-sliced ham melts in your mouth, with flavor that may rival even the finest European meats.
Once referred to as prosciutto’s “redneck cousin,” the South’s country ham industry is undergoing a transformation. Often served with grits and gravy, country ham has become increasingly popular with chefs seeking a local alternative to European dry-cured meats.
The fate of the Southern delicacy, however, lies not on the fickle tongues of foodies, but with environmental regulators and an international treaty.
For more than 30 years, Edwards – like many country ham producers – has used a single chemical to keep critters from infesting high-value hocks. That chemical, methyl bromide, is being phased out under a 1987 United Nations treaty because it is one of the most potent compounds depleting the Earth’s protective ozone layer.
The nation’s country ham producers – about 50 companies – are hanging on as they scramble to find a pest-killing alternative.
The ham industry is exempted under the U.N.’s Montreal Protocol, but its annual allocations of methyl bromide are shrinking. Next year, its allowable use will decline 9 percent from the amount allowed this year.
“If you were to take methyl bromide away today, we couldn’t produce our long-cured hams,” said Edwards, a third-generation country ham producer in Surry, Va.
Gregg Rentfrow, a meat scientist at the University of Kentucky, said the process of creating country ham is a throwback to the way food was preserved before refrigeration. Producers rub sugar, salt and spices into the meat. Water is forced out of the fibrous tissue and the ham dry cures.
That drawn-out process gives the product a rich flavor, but also leaves it more susceptible to bug infestations than its quicker cousin, the wet-cured ham. Wet-cured, or “city ham,” as Rentfrow calls it – think cold-cut slices sold at deli counters – is injected with a curing solution and takes only hours to complete.
Improved sanitary conditions have kept most critters out of many production facilities. “We don’t see a lot of problems with bugs like we used to,” Rentfrow said.
But some ham mites always sneak in, said Thomas Phillips, an entomologist at Kansas State University. “This group of pests co-evolved with human culture to specialize on stored food. They’re very good at getting in,” he said.
Not all country ham producers use methyl bromide. It’s the longer-aged, high-quality niche products that are at stake in the search for pest control solutions.
Mite infestations begin when ham is aged around four months, said Wes Schilling, a Mississippi State University food scientist. Country ham is aged anywhere from about 50 days to four years.
“Methyl bromide was like a sledgehammer,” Phillips said, adding that replacing it will take “a number of new tools in the pest control toolbox.” Phillips and Mississippi State researchers are mounting a three-year, federally-funded study to come up with alternatives.
The chemical was first introduced as a fire suppressant in the late 1800s, and used in fire extinguishers until the 1960s, when it sickened workers. The ability of the gas to snuff out fires by filling up every nook and cranny also made it a desirable insecticide for fumigating soil, wooden shipping containers, grain elevators and ham hocks.
Ham producers fill a room of dry-curing meats with methyl bromide gas at first sign of a mite. “The rule is if I see even one in a room with 5,000 hams, I am supposed to fumigate,” said Edwards, who uses the chemical three to eight times per year.
European producers, Edwards said, are allowed to have mites on their products during the dry-curing process, as long as they are removed before packaging and shipping. Some kill off mites by dipping their hams in hot olive oil, he said.
The phaseout of methyl bromide and other ozone-depleting chemicals has been hailed as a great success. In September, the United Nations reported that after 30 years, the ozone layer is finally starting to rebound.
But a few industries, for which governments deem “no technically or economically feasible alternatives exist,” according to the treaty, are allowed to keep using the pesticide.
There’s no timeline for when the ham exemptions will expire. Each year the EPA solicits applications for methyl bromide use. The U.S. government then nominates those exemptions to the countries that signed the Montreal Protocol. “The exemption period is intended to be limited and temporary to allow time for the development and implementation of alternatives,” wrote Christie St. Clair, an EPA press officer, in response to questions.
Year-to-year applications make it difficult for producers such as Edwards, who cures some hams for up to four years, to plan for the future. Edwards grew up in the business, learning the art of dry-curing from his father and grandfather.
– who sells his Surryano ham for more than $3 per ounce – about $500 to fumigate a room, while it now costs nearly $2,000.As methyl bromide has become scarcer, it’s also become more expensive. The rising cost may cause some producers to phase it out before the government does, according to Rentfrow. It used to cost Edwards
Candace Cansler, executive director of the National Country Ham Association, estimates that 50 companies make country hams, which comprise about 4 percent of all hams produced in the United States.
California strawberry growers are the biggest group still using methyl bromide. In 2015, they will be allowed to use about 370 metric tons. Country ham, in comparison, will be allowed about 3 metric tons. All uses amount to just a sliver of historical consumption. In 1991, the United States used more than 25,000 metric tons of the pesticide.
|Calendar Year||Amount Authorized |
|2016||To Be Determined Nov. 2014|
methyl bromide authorized for all critical
uses, mostly strawberries, in the U.S.
About 13 percent of California’s strawberry fields are dependent upon methyl bromide. But exemptions for strawberry growers will end after 2016, according to David Doniger, director of the Climate and Clean Air Program for the Natural Resources Defense Council in Washington, D.C.
“Because nearly all ozone-depleting chemicals have been eliminated worldwide, the ozone layer is slowly mending, and millions of skin cancer deaths have been avoided,” he said.
Experiments with two new mite-killing chemicals already widely used for treating grains and nuts have turned up mixed results. Phosphine gas killed mites in all stages of development, but it’s also corrosive to copper and other metals used in heating and electrical wiring. The chemical did about $25,000 in damage in a trial run at Edwards’ facility. Another option, sulfuryl fluoride, marketed as ProFume, killed adult mites but not eggs and larvae. Early trials have indicated that turning up the heat during fumigation may make ProFume more effective. However, sulfuryl fluoride is considered a potent greenhouse gas.
Phillips also has created bait stations, using pheromones to draw mites away from hams that are being tested in some ham facilities this year.
Researchers at Mississippi State are experimenting with gels and other food grade coatings made from seaweed to keep the mites off. “We’re testing what it does to the quality and flavor profile of the ham,” Schilling said.
So far, early tests of a new food grade coating have been promising, Edwards said. After four months, there were no mites and the flavor was “on the money,” he said. They still need to test the coatings for about another year to see if they stand up to the challenge of his long-cured products.
For producers, a solution can’t come fast enough.
“We want to be stewards of the planet,” Cansler said, "but we also need to make a living and employ the people that work for us.”
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