We’ll have a recipe this time, for live fermented kimchi. It’s non-technical and it doesn’t involve heat. With a bit of labor, you can make enough to last for months. Live kimchi doesn’t provide much in the way of calories, but it’s chock-full of fiber and healthy gut bacteria. It’s also a way for you to manufacture your own Vitamin C in the kitchen. Kimchi is high in both survival value and flavor. You can skip straight to the recipe here.
When we think of cooking, we mostly think of heat. You take a raw ingredient and apply heat; the heat causes chemical changes; at some point the ingredient is cooked and you call it food.
Fermentation is cooking without heat. You take a raw ingredient and let yeast and/or bacteria colonize it. Their metabolic activity causes chemical changes. At some point you call it cooked and start eating it.
Fermentation not only cooks, it preserves. Raw ingredients that would spoil in hours or days can be preserved for months.
There are endless variations on exactly what organisms are doing the cooking and what the chemical effects are. There are two main general modes of fermentation used around the globe: alcohol and acid.
In alcohol fermentation, yeast converts sugar into alcohol. (The Greeks figured out that if they stomped barefoot on sweet grapes, the resulting juice would turn into wine over time. They didn’t know they were inoculating the brew with wild yeasts, resident on their feet.) Starchy foods like grains and potatoes can be malted to produce fermentable sugar. Sugar cane, cactus leaves, berries…sugar from every possible source has been at least tried. The food preservation value of alcohol is straightforward.
Acid fermentation uses many different species of bacteria in a bewildering array of processes. The product is usually lactic or acetic acid. Using one technique or another, acid fermentation will cook just about any ingredient in the human repertoire. (Here’s an article on the microbiology of cheesemaking. It gets far into the technical weeds, but it’s worth at least skimming to get a notion of just how complex – and how controlled – these live-chemical processes can be.)
Sometimes yeast and bacteria team up on a fermentation project. For this to work, the yeast has to be one of the rare kinds who will tolerate a sour environment. In the case of kombucha, the yeast and bacteria cuddle up in a gelatinous blob. The yeast makes ethanol; the bacteria consume the ethanol to make acid and fizz. In the case of sourdough bread, the bacteria make it sour, and the yeast makes the bread rise and provides a host of twisty flavors.
Brewing alcohol and rising sourdough bread are ancient, borderline pre-civilization technologies. In these troubled times, we may be thankful that Divine Providence ordered things in such a way that trillions of invisible workmates would infest us every moment, ready to help feed and entertain us.
Perhaps the most famous of the acid-producting bacteria is lactobacillus acidophilus, which translates to “sour-loving milk-bug”, a lactic-acid producer. This little guy is all over the place; just make a home for him and he moves right in. Once he’s all moved in, he keeps the place tidy and spends all day cooking.
Lb. acidophilus is superbly adapted to certain extreme environments. You already know he’s an acid-lover. He also tolerates lots and lots of salt. For many undesirable microorganisms, sour and/or salty is a deal-breaker; they just die out, leaving Lb. acidophilus and a few close friends.
To achieve this condition, it is generally desirable to get water out of the food, and get salt in. Salting or brining the food heavily accomplishes both at once. Mechanical pressure is another way to remove liquids from the food.
The famous 18th-century British explorer James Cook sailed ’round the world at a time when scurvy was the terror of the oceans. He experimented with various preventatives and cures. Any foods or medicines brought for the purpose would have to go three years in the unrefrigerated hold of the ship, without spoiling. Somehow, Cook got the idea to pack barrels, alternating a layer of cabbage leaves with a sprinkling of salt; then screw-pack the contents to half their original volume, drain the excess water; then repack the top half of the barrel and hammer in the lid. Cook called it “sour kroutt” and he brought 8,000 pounds of the stuff on the first circumnavigation.
Captain Cook didn’t know how acid fermentation works or what Vitamin C is. He had several rations, thought to be preventive, which he doled out on a rigorous, sometimes non-voluntary basis. He didn’t know whether the sour kroutt was effective. But he knew something was working:
The Ship’s company had in general been very healthy, owing in a great measure to the Sour kroutt, Portable Soup [bouillon] and Malt; the two first were served to the People, the one on Beef Days and the other on Banyan Days. [fermented] Wort was made of the Malt, and at the discretion of the Surgeon given to every man that had the least simptoms of Scurvy upon him. By this means, and the Care and Vigilance of Mr. Monkhouse, the Surgeon, this disease was prevented from getting a footing in the Ship. The Sour Kroutt, the Men at first would not eat it, until I put it in practice–a method I never once Knew to fail with seamen–and this was to have some of it dressed every day for the Cabin Table, and permitted all the Officers, without exception, to make use of it, and left it to the Option of the men either to take as much as they pleased or none at all; but this practice was not continued above a Week before I found it necessary to put every one on board to an allowance; for such are the Tempers and disposition of Seamen in general that whatever you give them out of the common way–altho’ it be ever so much for their good–it will not go down, and you will hear nothing but murmurings against the Man that first invented it; but the moment they see their superiors set a value upon it, it becomes the finest stuff in the world and the inventor an honest fellow. Wind easterly.
How to ferment your own live kimchi at home. (Sauerkraut is the exact same process, just without all the flavor ingredients.)
Feel free to skip ahead to the recipe, there’s a link back here so you can check the Recipe Notes.
Recipe Notes: Equipment and Techniques
A big head of cabbage makes almost a gallon of kimchi, which means you need some large vessels for mixing and brining and fermentation. For the salt/brine part of the recipe, an extra large, wide vessel is best; about one gallon more capacity than the amount of kimchi you’ll make. A plastic dish tub will suffice for this part. I use a big deep enamelware baking pan, which is nice because it has a lid.
Nitrile gloves are recommended for the part where you mix in the spice paste.
For the fermentation part, you need a glass or ceramic vessel. A gallon mason jar will suffice, though the narrow opening makes it inconvenient to get at the brew. There are fermenting crocks made for the purpose, they are handsome and have large capacities: as much as three gallons. I like to look at my kimchi from the side, so I keep it in a 2.5-gallon glass crock I picked up cheap at Wal-Mart.
The lid on the crock does not form an airtight seal; it’s just there to keep dust out. If you use a mason jar, leave the lid loose.
The salting process produces a quantity of brine. There are two main schools of thought: ferment the final product in this brine, or discard the brine and ferment in fresh water. Some advocates of brine-packing have exact recommendations, by weight, of how to get the salinity right; as though everyone has a kitchen scale that can measure fractions of grams.
It’s way easier to just discard the brine. You can confidently oversalt that brine, knowing you won’t have to eat it later. Yes, the kimchi will take on a little water after brining.
If you’re a novice with a knife, beware the cabbage. When you try to shove a knife through a cabbage, it has a way of rolling over on your left hand. Use a gentle slicing motion to get the knife well in the groove, before applying force. If you’re unsure how to cut the other vegetables, I’ve cued up this video to the part where Billy Parisi demonstrates basic slicing and dicing (about two minutes). For mincing garlic and ginger, refer to Spain on a Fork, where he demonstrates the rocking technique with the left-hand fingertips on top of the blade.
Once you’ve got all your vegetables cut up, you put them in the tub with lots of salt. Then you “massage” the salt into the vegetables with your hands. This could be a science fair demonstration, because after a little bit of mashing and heaping and tossing, the salt dissolves and the vegetables start to get wet. That’s the beginning of osmosis: water is coming out of the plant tissues, and salt is going in.
Once you get the osmosis under way, you cover the veg with water and let it soak in the resulting brine. Soaking in that salty brine will dry the vegetables out and make them crisp, counterintuitive as that may seem. Up to a point, more salt means a crisper end product.
Sliced cabbage is a bouyant, lively fellow who always wants to stick his head out of the water and have a look around. It’s important to weight the soaking cabbage with a plate or similar, to keep the cabbage submerged. Any cabbage exposed to the air will rust, and rusted cabbage is not only ugly, it gives a foothold to spores and slimes that can spoil your brew. The same goes in the early stages of fermentation; you want to check in periodically and stir the stuff under. As fermentation proceeds, cabbage becomes more sensible and sedate, residing mellowly below the surface.
When packing kimchi for fermentation, it’s important to leave headspace, especially in a tall narrow vessel such as a jar. When cabbage that has been dried in brine finds himself in less salty water, he swells up a bit while retaining his bouyant personality. This swelling can cause the vessel to overflow in the early stages of fermentation, so it’s a good idea to keep the vessel on a sheet pan or similar to catch any drips. Adequate headspace in a gallon jar is about two inches of clearance for the kimchi itself, and one inch of clearance for the liquid. If the cabbage swells so much you can’t stir it under, take some out and eat or discard it. Keep your kimchi submerged.
- Cabbage: the standard cabbage for kimchi is the Napa cabbage. Its leaf structure is gossamer compared to the bony leaf structure of standard green cabbage. I prefer the latter as having more crunch and squeak.
- Salt: do not use table salt. Table salt has iodide and other additives that don’t do well in fermentation. Pickling salt is pure sodium chloride. Kosher salt is the exact same pure chemical, just not as fine a grind. I like the kosher salt because it “feels” better, but it makes no difference once the salt dissolves.
- Water: tap water is okay for the salting-brining part. Use filtered or better water for the fermentation part.
- Garlic: Optional / do not overdo. Garlic retains his sharp, sulfurous character despite fermentation. It might be worth experimenting with roasted garlic.
- Ginger: Optional / do not overdo. Like garlic, ginger also remains pretty raw in the brew. It might be worth experimenting with pickled ginger.
- Sugar: I like a raw sugar, which includes Turbinado, Palm Sugar, and Indian Jaggeree.
- Fish Sauce: Optional. If you don’t like fishy umami flavor, retain a little brine as a substitute. You can also substitute just about any salty umami ingredient, such as salted shrimp paste or anchovy paste. Some people add minced raw oysters.
- Korean Red Pepper Flakes: Koreans are the world leaders in fermenting everything they eat. They, and they alone, have a spice evolved for fermentation; any substitution is likely to be regretted. American chiles are delicious, but they are evolved for heat cooking; in fermentation they might turn out oily, bitter and raw. Cayenne might ferment well, but it’s too pungent and lacks the characteristic flavor. The Korean flakes feature moderate heat, they seem strangely “dry”, and they really do resemble tiny flakes of shiny red glitter which adds a handsome color component to the dish.
(Recipe techniqes detailed here, details about ingredients here.)
Ingredients:
- One medium-large head of Napa or green cabbage
- 1/4 cup Kosher or pickling salt
- Filtered or distilled water
- Spice Paste:
- 1 tablespoon minced garlic (optional)
- 1 teaspoon peeled minced ginger (optional)
- 1 teaspoon raw sugar
- 2 tablespoons fish sauce, salted shrimp paste, anchovy paste, or brine
- 1 to 5 tablespoons Korean Red Pepper Flakes aka gochugaru
- 1 cup Korean radish, daikon radish and/or carrot, peeled and cut into matchsticks
- 4 medium scallions, sliced thin
Quarter the cabbage and remove the stem from each quarter with a diagonal slice. Remove any outer leaves you don’t care to eat, and slice the cabbage (say, 1/4″ slices or so), starting from the leaf end and working towards the stem end.
Put the cabbage in a dish tub, full pan or similar. Add the salt. Mix thoroughly, rubbing the salt into the cabbage with your hands, until the cabbage gets wet and the salt dissolves.
Cover the cabbage with water (tap water okay). Weight the cabbage with a plate or similar to keep it submerged. Soak for two hours. Cut up the root vegetables and the scallions.
Drain the cabbage and rinse three times (retain a little brine if you don’t want to use the fishy ingredients). Set it to drain thoroughly.
In a bowl, mix garlic, ginger, sugar, fish sauce, and pepper flakes.
Put cabbage and other vegetables in the mixing tub. Add the spice paste, and again using your hands thoroughly rub the paste into all the vegetables. Nitrile gloves will protect your hands from getting stinky or spiced.
Transfer all ingredients to your fermentation vessel(s), leaving one or two inches of headroom. Cover with purified water, place the vessel on a pan to catch drips, and allow to ferment. If your vessel has a screw-type lid, leave it loose; fermentation produces gases. Check several times daily, especially at first, to stir the cabbage back under when it wants to float out. If the cabbage won’t fit under the water, take some out.
In Korea, they do most fermentation at 40 degrees Fahrenheit. Kimchi will ferment just as well, and considerably faster, in the 50-60 degree range. At 70 degrees, fermentation is rapid and results in a soggier product with different flavor. Once fermentation is complete, the batch must be moved into refrigeration. Ambient slimes and spores can take root in warm kimchi when the bacterial competition is played out.
Estimates of how long to ferment kimchi are all over the map. At moderate temperatures, you’ll be able to detect the sourness in a couple of days. I like the sourest possible kimchi myself. Once it’s in the fridge, it will continue to ferment indefinitely but any change will be slow and small.
The odor of kimchi is funky, but it’s not foul. If slimes and molds get into your kimchi, you’ll be able to tell. Most common is a white or pink slime on the surface, with a rank odor. If you have any doubt, it’s probably fine.
With such a funky, spicy concoction, you’d think it would tend to heartburn and indigestion. But it actually soothes the digestive tract. Between the fiber and the pro-biotics, it feels good to eat the stuff.
Enjoy!