1/26/2013 7:00 AM
By Shannon Sollinger Virginia Correspondent
LEESBURG, Va. — For thousands of years, humans have used fermentation to keep their vegetables coming to the table long after the growing season is over.
Sandor Ellix Katz, a self-described “fermentation revivalist,” led a workshop on wild fermentation at the 14th annual Future Harvest CASA (Chesapeake Alliance for Sustainable Agriculture) Conference Jan. 18 at the National Conference Center in Leesburg.
Wild fermentation, he explained, means simply that the bacteria already present on the vegetable do the work for you. If you add a culture — sourdough bread, yogurt — that’s fermentation, but not the “wild” variety.
His definition is simple: “Fermentation is the transformative action of microorganisms.” Presto: A container full of cabbage, carrots, garlic and beets becomes sauerkraut.
To be honest, he conceded, when food rots, that’s a metabolic transformation, “but not fermentation.”
“Fermentation is the creative space between fresh and rotten,” he said.
The trick is to get the “good” bacteria to work before the “bad” ones — the ones that turn cabbage to a pile of slime rather than crunchy sauerkraut —can get started. You do that by controlling the environment — in this case, keeping the vegetables underwater (their own water) where there’s no oxygen.
And all raw plant materials are natural hosts to lactic acid bacteria, the ones the fermenter wants to put to work.
Katz assembled his uncomplicated, “you can do this at home” fermentation arsenal: the vegetables, several quart jars, a knife, a grater and salt.
“We cut the vegetables up to create more surface area and add salt to remove water,” Katz said.
Then submerge the vegetables under the water and let the lactic acid bacteria go to work. Underwater there’s no air, and molds need air to thrive. The lactic acid bacteria are at home in that anaerobic environment.
Katz called the process “simple environmental manipulation” to encourage the growth of certain organisms and discourage the growth of others. The USDA, he claimed, has never documented a case of food poisoning from sauerkraut. “You can’t say that about other vegetables,” he said, citing recent outbreaks of food poising traced to tainted spinach and tomatoes.
“If our cabbage had been contaminated, the lactic acid bacteria acidify the environment and that destroys the bad’ bugs. This is a strategy for both preservation and protection.”
Canning is the opposite, he said. It uses heat to sterilize the vegetable and kill all the bugs, good, bad or indifferent. Unfortunately, the high heat also leaches nutrients, particularly vitamin C, out of the food, and “Clostridium botulinum (commonly found in soil) has a high tolerance for heat and thrives in the absence of oxygen.”
The most widespread use of fermentation over the centuries has been the production of alcohol, Katz said. Right after the still, in temperate regions, comes the use of fermentation to preserve food for long periods of time.
“Milk becomes cheese, meats are cured and vegetables become sauerkraut. Now you have a vegetable for the rest of the year.”
Soybeans, for instance, supply as much protein as a steak. But unless you have a four-chambered stomach, you can’t digest them. But those transformational microorganisms break those proteins down to their constituent amino acids — they “predigest” them for the single-stomach consumer — and you have soy sauce, miso and tempeh.
Second, fermentation detoxifies. Consider the casaba melon, Katz said. “In some soils, it has a high concentration of cyanide. Chop it up, put it in water and the cyanide is broken down to a benign form.”
Finally, fermentation augments the nutrients in the vegetable. Fermenting vegetables, especially the dark green cruciferous ones — broccoli, cabbage and kale — breaks some natural compounds down into isothiocyanates, which “may help prevent cancer by promoting the removal of potential carcinogens from the body,” according to Oregon State University Linus Pauling Institute.
Katz worked the chopped up, salted vegetables with his gloved hands, wrung them out (helps break down the cell walls and remove the water), and stirred the mixture around.
In some indigenous cultures, he said, the vegetables go into a barrel and children — their feet suitably cleaned — hop in to jump up and down and process the water out of the plants’ cell.
Then it was into the quart jars. Tighten the lid, he said, take it home and put it on your counter. Loosen the lid once a day to let any accumulated carbon dioxide out and relieve pressure — most of that production takes place in the first few days.
How long should it sit on the counter? Until it pleases your taste, he said. That might be three days, three weeks, three months. Even three years.
When it has reached the taste and texture you like, put it in your “fermentation slowing device” (aka refrigerator) and it will keep for years.
Consuming fermented foods is good for you, Katz said. It repopulates intestinal flora. It is thought to strengthen the immune system and improve brain chemistry. But it is not a magic bullet.
“To say it is a cure for AIDS is a vast exaggeration. I am very skeptical that any food will solve all our problems,” he said.
Avis Renshaw, a Loudoun County farmer and proprietor and cook at Leesburg’s Mom’s Apple Pie, attended the workshop to extend her “personal quest to learn more about nutrition,” she said.
She said she appreciated his “saying it’s not a cure for anything, but a way to help your health.”
Renshaw said she has applied for a vendor’s slot at the Leesburg Farmers Market and, if accepted, will be adding fermented products to the fresh vegetables on the table. The problem with selling fresh vegetables — she concedes it is less of a problem with farmers market shoppers — is that people don’t cook the way they used to. Fermented vegetables, she said, “they can eat right away.”