I was intrigued by a recent Terry Gross interview with Sandor Ellix Katz about his book "The Art of Fermentation: An In-Depth Exploration of Essential Concepts and Processes from Around the World". Katz explains that fermented foods and beverages have been prepared by humans for over 8000 years. Fermentation is the process whereby cultures of micro-organisms (usually bacteria or yeast), often microbes already naturally present in the food or surrounding environment, are allowed to establish and grow in the food, enhancing flavor and, Katz believes, providing numerous health benefits. (Our own bodies normally contain vast -- VAST -- numbers of living bacteria and other microorganisms, known as our "microbiome", though this fascinating topic is way beyond the scope of this post.) As they grow in the fermenting foods, the microorganisms digest carbohydrates and produce byproducts that impart characteristic flavors. (See "glycolysis" in your biochemistry texts.) For example, both wine and beer are fermented beverages, with sugars converted by yeast to alcohol (and carbon dioxide). In the case of some other fermented foods, lactic acid is the product contributing to the characteristic flavor and texture. Lactic acid gives pickles and sauerkraut their sharp sourness, and the extent of acidity can be controlled, for example, by moving the product to the refrigerator to slow bacterial growth.
In his book, Katz cites an estimate that up to one third of all foods eaten by people worldwide is fermented! Some of the most obvious are the foods and beverages mentioned above, and yogurt. Less obvious are cheese, coffee and bread. Think of those beautiful, strong-flavored ("tres fort") French cheeses laced with colorful, happily metabolizing molds. In bread, the yeast also generate ethanol and carbon dioxide, and the carbon dioxide bubbles help the dough to rise. Katz's interview made me realize that I already use fermentation routinely in some of my cooking, for example, in sourdough bread. I knew already that the sourdough starter that's been brewing in my refrigerator for well over a year is a living culture -- one that seems to rebel by giving me misshapen bread loaves if I ignore it for too many weeks. But, I hadn't quite appreciated its connection to beer, wine or sauerkraut.
Yeast breads are good examples of fermented foods, since the carbon dioxide, produced as the yeast metabolize carbohydrates in the mixture, causes the dough to rise. Sourdough breads, like this one, rely even more on fermentation, since the sourdough starter itself is a simmering culture.
So, I decided to try making other fermented foods, inspired by vegetables growing in our Robbins Farm garden. Katz told Terry Gross that sauerkraut is the simplest fermented food for the beginner. Plus, beautiful fresh cabbage is available in our garden and in local farms right now. I followed the basic procedure suggested by Katz in the radio piece. Essentially, veggies of choice are salted to extract their juices, these juices are squeezed from the vegetables and they are allowed to ferment in their own juices in a sealed jar. Katz advises not adding more water unless it is needed to cover the vegetables, because this will dilute the flavor. I did need to add a little water (he said the vegetables should be covered with liquid) but it did taste pretty good, seasoned only with salt and black pepper. I used fresh green cabbage, scallions and carrots. (Because of availability, only the scallions were from our Garden, while the other vegetables were from Busa Farm.) As Katz had promised, it was a simple dish to make.
My first (only, so far) attempt at sauerkraut, using locally grown green cabbage, scallions, and carrots, and the guidelines described by Katz in his radio interview.
Emboldened by my relative success, I decided to next try making kimchee (or kimchi), the Korean staple that happens to be one of my favorite foods. There are probably as many different kimchee recipes as there are for wines and cheeses. Katz didn't offer a kimchee recipe in his book but I found a recipe online for "Basic Nappa Cabbage Kimchi (Kimchee)" that looked about right. This time, I was able to use nappa cabbage from our Garden. I followed the recipe closely, but used half of all ingredients since it was written for 2 lbs of nappa cabbage. Consult the recipe for further details, but essentially, I began by washing and cutting the cabbage and soaking it in salted water for about 24 hrs, then rinsing and draining it, squeezing out the excess liquid. This leaves it somewhat wilted in appearance. Regarding the other ingredients, I first searched a few Asian markets in the Chinatown area (near where I work) but was concerned that the ingredients, especially the fish sauce and red pepper powder, were not necessarily the Korean style. So, I headed to the amazing, though somewhat overwhelming, H. Mart in Burlington. Here the selection is great, with separate sections for Korean sauces and other items. (And, as it happens, H. Mart carries many types of prepared kimchee, sold in jars in the refrigeration cases, or in bulk by the pound.) To my surprise, even the daikon radish was available in both Chinese and Korean variations, so I took the Korean one. Both are plump and white, but the Korean had a greenish color at the base. Again, the red pepper powder selection was huge, with coarse and fine options and many different brands. I took the one that said "For Kimchi" on it, a coarse grind. While it was produced in China, it was packaged in Korea and, of course, the "For Kimchi" label gave me comfort that it was the right kind.
Shown here are several of the ingredients I used for kimchee. Clockwise from front: Daikon radish ("Korean" according to H. Mart), wild salted shrimp, Korean style fish sauce, Napa cabbage from the Garden (after soaking in salt, draining and squeezing out excess liquid), Coarse ground red pepper powder (marked "For Kimchi"), ginger root. Not shown: scallions
Preparation in progress, prior to adding cabbage and fish sauce to pack into jars.
As I write this, my 1 qt jar of kimchee, after brewing in the basement (a cool, dark place) for a little over 24 hrs, is now fermenting in the refrigerator. Before transferring it to the refrigerator, I opened the lid to release the gases; and, there were gases so we're on the right track!. To be continued......
Additional tips from my friends who have experience making kimchee: Val Hays has used, and recommends, another Kimchee recipe by David Lebovitz. While similar to the one I used, it does not have the salted shrimp, making it a good vegetarian option. MJ Keeler suggests letting the kimchee ferment in the refrigerator for at least a week, rather than the three days (minimum) suggested by the recipe. As I post this, it's been in the refrigerator for three days and we haven't tasted it yet.
Update: We have eaten some of this. It is okay, but I am not thrilled with it. The cabbage is a little tough, and the taste a little bitter. Today (August 11) I got another half cabbage, shared with Dick. I am going to try the other kimchee recipe in this post (David Lebovitz). However, I am slightly concerned that it is our nappa cabbage that is bitter or tough. We will see.....
p.s. Gardeners: I have plenty of the red pepper powder and salted shrimp, as well as extra 1 qt canning jars. Let me know if you want some to try this on your own.