Fermentation is one of the oldest forms of food preservation. While the word fermentation usually brings to mind the conversion of grains or fruit into beer and wine, it also covers microbial actions such as the conversion of starches and sugars into lactic acid. This lactic acid is what gives the tangy sour flavor to sauerkraut, kimchee, salami, sourdough, and yogurt. Vinegar is created by similar manner by bacteria which convert the alcohol into acetic acid. The lactic and acetic acids prevent other microbes from growing and spoiling the food.
These beneficial, acid-producing bacteria are found all around us naturally and under the right conditions they can easily be harvested. "Wild-type" bacteria don't always give great results so most people purchase bacteria which has already proven to be a good performer. The easiest way to buy them is in the form of yogurt with live culture. Strain the yogurt through cheesecloth and the resulting liquid is loaded with live lactic acid-producing bacteria. Lactic acid bacteria can also be bought in pill form in the vitamin section of most stores. Look for pills labeled Probiotic Acidophilus. To use, simply crush 1-2 of the pills and add the resultant power to your fermentation crock. These bacteria will reproduce and feed on some of the plant material to produce the lactic acid.
Probiotic Acidophilus containing 1 billion active cultures per tablet.
Acetic acid producing bacteria can be found in certain unpasteurized vinegars such as Bragg's Apple Vinegar and some English malt vinegar. You can also purchase acetic acid bacteria "mother" from various places online.
The acid will attack most metal containers so ceramic, glass, or plastic vessels are used to hold the fermenting food. Traditionally large, straight-sided, wide-mouthed ceramic crocks were used and these still can be purchased from assorted online vendors. They are expensive though and usually outside the budget of most people just getting in to fermented foods. Luckily, circular ceramic crockpots and slow-cookers work just as well and are usually available from second-hand stores for under $10. Since the fermentation takes place at room temperature, the crockpot is left unplugged the whole time. The crockpots need to be circular in shape so a plate can be placed inside the crockpot to weigh down and completely submerge to food being fermented under the fermentation liquid. The acid-producing bacteria are "anaerobic" which means oxygen will prevent them from reproducing and must be excluded. Keeping the food submerged keeps the oxygen away, allowing the bacteria to do it's thing. Usually a weight is placed on the plate to keep everything submerged. I use a pitcher of water as the weight.
Sauerkraut: An Easy Fermented Food.
Sauerkraut (fermented cabbage) is one of the easiest fermented foods to make but it is also extremely nutritious. Sauerkraut is simply sliced cabbage with a little salt. More complex sauerkraut recipes call for additional things like apples, onions or spices such as dill and fennel. For your first time just stick with the basics.
5 pounds of cabbage
3.5 tablespoons of sea salt (optional).
1-2 Probiotic Acidophus pills.
The salt isn't really necessary but adding it will help prevent "bad" bacteria from taking over while you are waiting for the acidophilus bacteria, which is unharmed by high salt concentrations, to grow. The acidophilus pills aren't need either as this sort of bacteria is already all around us and even on the cabbage leaves. I normally don't use these pills except when the weather is exceptionally cold resulting in slow-reproduction of the wild-type bacteria.
Step 1: Gather your stuff.
Here we have the cabbage, crockpots, bowls, and sea salt. I use sea salt as it contains extra minerals that assist the bacteria in the fermentation process. Only one crockpot will be need to hold the cabbage.
Step 2: Slice the cabbage.
Peel off some of the outer cabbage leaves to get to the cleaner interior leaves. Also "core" the cabbage to remove the stem base. The stem base doesn't ferment well as it is large and solid which prevents the bacteria from getting into it. Some people puree the stem base and add it into the crock, but that just makes extra dishes. I'm lazy so I just feed the core to my worms.
Step 3: Salt the cabbage.
Sprinkle some of the sea salt in the bottom of a large bowl, followed by some of the sliced cabbage. Continue to alternate layers of salt and cabbage. If you are adding crushed acidophilus pills do it at this same time, also in layers with the cabbage. Once the bowl is filled mix the salt and cabbage together with your hands while also crushing the cabbage to make it release its juices.
Step 4: Packing the cabbage in the crock.
Tightly pack the sliced cabbage into the crock. You want to press hard on it to drive out any air and also to squeeze more juice out. You need enough juice to completely cover all the cabbage. The salt will help draw out some of the water from the cabbage so don't worry if it at first is seems like there isn't enough juice. After a few hours a lot more juice will be freed from the cabbage so its rare that extra water needs to be added.
Step 5: Submerge the cabbage, part 1.
Place a plate on top of the cabbage to press it down under the water. I usually place a cup or an upside down bowl on top of the plate, followed by a cloth covering and then a pitcher filled with water on top of the cup or bowl. The pitcher increase the weight on the cabbge insuring it will stay submerged.
Step 5: Submerge the cabbage, part 2.
Here you can see the cloth covering and the pitcher of water. The cloth keeps out any dust, spores, or flies that might want to contaminate the sauerkraut. The pitcher adds weight to keep stuff submerged. At this point depending on the room temperature it will take anywhere from four days to four weeks for the cabbage to reach the proper level of spicy, yummy fermentation. Check it every two to three days during this time to remove any "blooms". Blooms are simply white fuzzy/spiderwebby stuffy. It is non-toxic but kind of icky looking and can impart odd flavors to the fermented veggies if not removed.
A spider-webby bloom. Just remove it, the sauerkraut will be fine.
Step 6: Eat!
Deciding when sauerkraut is "finished" is very subjective and only depends on your particular tastes. Visually it'll have a slightly translucent appearance but what really matters is the taste. If you like the way it tastes then it is finished. Pack the sauerkraut into covered glass or plastic jars and stick it in your fridge, making sure you included enough of the juice to keep the sauerkraut submerged. The batch shown being made for this article filled two quart jars.
The cold temperature of the fridge will cause bacteria growth/fermentation to slow almost to a standstill, no more lactic acid will be produced. The sauerkraut will then stay in this edible state for years.
In Mexico slices of carrots and peppers are treated this way. Kimchee is just Asian cabbages and other Asian vegetables mixed with spicy peppers and assorted seasonings and allowed to ferment into a fiery, tangy dish. Any plant can be fermented, whether it tastes good or not is up to you. I plan on making a kimchee-style dish using smartweed, dollarweed, spiderwort, chili pequins, and assorted other wild edibles. Hopefully it'll turn out fantastic...or at least edible.
Next up, a bunch of stuff mixed together.
Update on the cauliflower/daikon radish/ginger/carrot/hot pepper mix: it's fantastic!!
Buy my book! Idiots Guide Foraging covers 70 of North America's tastiest and easy to find wild edibles shown with the same big pictures as here on the Foraging Texas website.