I would encourage anyone who's around Cambridge or Somerville either of the next two weekends to go check it out. And I would encourage folks in other cities to do something similar to the Market Stand! It gets folks thinking about food (and other topics) a little more deeply. They come home from the market not only with a bag of turnips, but with new insights into those turnips.
Below are the notes that I distributed to go with my presentation.
FERMENTING VEGETABLES
Today, most of the food we consume has been preserved in one way or another. We rely heavily on refrigeration, freezing, and sterilization/canning. These are all modern techniques. Refrigerating and freezing were impractical during harvest season until recently; canning dates back only to the early 1800s.
Vegetable fermenting is an older preserving technique. There is evidence of fermented kimchi, a close relative of sauerkraut, from as long ago as 600-1000 BCE.
Fermentation relies on the action of microbes to change the chemical composition of our food. Lactofermentation of vegetables, in particular, takes place when Lactobacillus and other types of human-friendly bacteria convert naturally-occuring plant sugars into lactic acid. As the acidity rises, the medium become less and less hospitable to other microbes—most notably the human-unfriendly ones.
Fermentation has advantages over other preservation methods.
When you compare it to canning, you find that fermentation creates an ecosystem in a state of stable equilibrium. You don't have to start your fermentation from a completely sterile state; in fact, you can't! Fermentation also preserves, even enhances, enzymes and vitamins that are diminished or destroyed by the heat of canning.
Fermenting vegetables does not require any electricity. It requires only some salt, to give the Lactobacillus a head start over the human-unfriendly bacteria, and an ambient temperature between roughly 50 and 80 degrees Fahrenheit, which can be found by digging down a few feet into the ground, even at the height of summer or in the depths of winter.
Many raw plants contain compounds that our bodies can't process very well. Fermentation helps us here by breaking down these compounds. Fermented cabbage and fermented soybeans are much more digestible than their unfermented counterparts, for instance.
Finally, fermenting vegetables is fun, and provides a great way for you to get back in touch with your food—literally!
HOW-TO
Choose freshly-picked vegetables. Prime candidates include cabbage, turnips, rutabagas, and radishes. In my experience, these work excellently (presumably because they tend to host healthy colonies of Lactobacillus). You can ferment just about any other vegetables, too, but I would advise combining them with one of the vegetables I mention above, or with a starter. The easiest starter to use is a portion of fermented vegetables or juice from a previous batch.
I like to combine turnips, beets, and parsnips. Cabbage, onions, and carrots. Or just turnips on their own. Any of these will work.
Wash and/or peel the vegetables. Cut off any parts you're not using.
VARIATION 1
Weigh the vegetables. For every pound of vegetables, allocate two teaspoons of salt. Alternatively, for every kilogram, use 20 grams of salt. This works out to roughly 2% salt by weight. Use sea salt or Kosher salt that is free of additives.
Slice or shred the vegetables finely, with a knife or a box grater.
Mix the vegetables together with salt. Add herbs and spices as desired. Pack the mixture tightly into Ball jars or other jars with tightly-closing lids, leaving at least an inch of space at the top. Really push down on the mixture until liquid starts to rise over the top. Close the lid. Leave it at cool room temperature. (Root cellar, cool pantry, or bury it!)
Every day or two, open the lid, taste it with a clean fork, push down until liquid rises again, and replace the lid.
When you like the way it tastes, start eating it! The colder you store it, the more slowly it will sour. When it becomes very sour, it can still be used in soups and stews.
VARIATION 2
Put the vegetables, whole or in pieces, with herbs and spices as desired, into large Ball jars with tightly-closing lids. Using water that is free of chlorine, make a 6% brine by dissolving 60 grams of salt per liter of water, or approximately 4 tablespoons per quart. (The brine should be at room temperature.) Pour the brine into the jars to cover the vegetables, leaving a little space at the top. Close the lid tightly.
Wait a week, or much longer, before opening the lid.
Eat the vegetables!
(For variation 2 in particular, apparatus can be helpful, to keep the vegetables under the liquid and to keep the "bad" microbes at bay. I've had excellent experiences with
Pickl-It, for instance.)
[UPDATE: see here for some more thoughts about airlock contraptions.]
BIO
Alex Lewin is a fermenter, health coach, software engineer, real food activist, and urban biker. He authors a blog called "Feed Me Like You Mean It". He thinks that Ball jars are the ultimate glassware. His heroes include Sandor Katz, Vandana Shiva, Anthony Bourdain, and Kurt Vonnegut.
RESOURCES
Real Food Fermentation, by Alex Lewin
http://tinyurl.com/vegferment
Wild Fermentation, by Sandor Ellix Katz
