Kimchee Party! a Recipe and a Primer on Fermentation

Kimchee (also spelled Kimchi) is traditional Korean spiced fermented Napa cabbage, famous for being a great probiotic food and for being one of the cornerstones of Korean cuisine. There are other Kimchee instructables out there, but several things set this particular one apart:

I've incorporated an optimization from the European sauerkraut making traditions into my method.
I incorporated the Bay Area's favorite leafy green superfood, Lacinato kale (a.k.a. Tuscan kale or dinosaur kale), into my recipe.
I include a primer on fermentation that gives you a nerd's-eye view of fermentation that will give you an understanding of what it is all about.
I show you details about inexpensive but perfectly functional fermentation vessels that cost less than a tenth of what European style stoneware fermentation crocks cost.
This recipe doesn't leave out the ingredients westerners might be squeamish about— fish sauce and tiny salted shrimp or krill. Although these ingredients are overwhelming when tasted by themselves, they are the secret to a great tasting savory kimchee. I'll explain why in the corresponding step.
Many of the steps are taken in the first-person-shooter perspective, so you know what you'll be looking at when you actually put your hand to the task.

The secret to food preservation:
Make food inhospitable to microbial decomposers

Did you know that foods do not decompose without biological intervention? The food may oxidize or dry out or go stale (starch retrogradation), and some substances may be unstable and break down into a more stable form, but if you took food, sealed it in a totally sterile bell jar filled with an inert gas, and irradiated all the microbes to death, it would never rot. It would sit there like the 14 year old McDonald's burger, forever untouched by decomposition as we know it. This is because decomposition is not merely oxidation and dehydration; decomposition is carried out by decomposers—yeasts, bacteria, molds, worms, insects, or the digestion of some creature. The microbes that would gladly eat your food for you are everywhere; their spores are in the air, and they are often symbiotic with the produce that we buy, naturally occurring on the surfaces of the leaves and fruit. In the days before refrigeration, the options that we had for preserving food were fairly limited, and broadly speaking, they fall into several categories:

Chilling: store the food where it is cool, such as a cellar or a zeer pot (non-electrical refrigerator). The cooler temperatures hinder the onset of decomposition long enough for you to eat your food first. (This is generally not very long without freezing cold temperatures.)
Killingthe microbes:
- Salting / curing: with enough salt, the food becomes osmotically hostile to any microbe. Salted fish, fruits, meats, and vegetables essentially resist microbial decomposition by dehydrating all the resident microbes to death.
- Drying: drying out a food can also be done simply by exposure to sun and dry air. This achieves the same outcome: the microbes present on the food and in the air find the dry food inhospitable, and either become dormant or die of dehydration.
- Smoking: smoking foods will impart chemicals from smoke that are naturally anti-microbial; this hinders any microbes from attacking the food from its surface.
- Candying: sugar, when used in sufficient concentration, will also make a food osmotically inhospitable to microbes. Jams, jellies, and preserves fall under this category.
- Acidifying or alkalizing: Vinegar can make a food too acidic for most microbial decomposers to survive, and is commonly used to pickle foods without direct fermentation, though most historic pickling methods produce the acid by bacterial fermentation. (Vinegar itself is a secondary fermentation product of wine or other alcoholic liquids.) Alternatively, some forms of this method of preservation use lye to make the food too alkaline for decomposers, such as the legendary Scandinavian lutefisk.
- Canning: Although canning as we know it is really pasteurization, and was not practiced in ancient times due to the inability to reliably seal a vessel against infiltration by microbes, canning is another low-tech way of preserving food that relies on killing all the resident microbes in a food by exposure to heat. Sealing the canning vessel prevents the infiltration of other microbes, thus preserving the food.
Fermenting: fermentation is essentially selecting what microbe (or microbes) you want to take over your food, and using the preferred microbes' natural defenses to fend off unwanted microbes.

How fermentation preserves food:
One form of filth kills another form of filth

Fermentation is best described as human intervention into a three way microbial war for the purpose of preserving food and enhancing its flavor. These are the three major combatants in this microbial war:

Yeast, which produce alcohol that kills bacteria and molds
Bacteria, whichproduce acids that kill molds and yeast
Molds, which produce digestive enzymes and antibiotics that kill yeast and bacteria

These three battle for supremacy over who gets to take over our food, and in the course of doing so, produce substances which fend off the colonization and growth of the others, particularly the decomposers. This microbial chemical warfare is memorably summarized by the observation that one form of filth kills another form of filth. [1] What we do when we ferment is to make alliances with the microbe of our choice by creating conditions favorable to that particular kind of microbe so that they can take over our food; in exchange for letting them utilize some of the calories in the food, we utilize their natural defenses to ward off unwanted microbes that would decompose the food or cause food poisoning.

In some forms of fermentation, such as Kombucha (fermented tea), we ally ourselves with two classes of microbes at the same time—bacteria and yeast. In others, such as Sake (Japanese rice wine), we switch sides midway through; in sake, mold is used to break down rice starch into fermentable sugars; then, the alliance with mold is broken as the moldy rice is mashed up to break up the mold structures; the mash subsequently liquefied and fermented with yeast, which convert the sugars into alcohol. For vinegar, yet another stage of fermentation is carried out where acetobacter bacteria are employed to convert alcohol (in low enough concentration that it won't kill bacteria) into acetic acid. In the case of rice wine vinegar, all three of the microbes are employed one after another. Many cured meats such as salami and cheeses such as brie are cured with penicillium mold, which colonize their outer surfaces and prevent the infiltration of harmful bacteria. Miso (fermented soy bean paste) is fermented with koji mold and preserved with salt. Sour cream and yogurt are fermented with various kinds of lactic acid bacteria and get their characteristic sourness from lactic acid and other flavorful acids.

In the case of kimchee, the fermentation is carried out by yeast and bacteria, with bacteria being the dominant player.

Fermentation for flavor and nutritional enhancement

In addition to fending off unwanted decomposers, fermentation has several great side effects, one of which is the enhancement of flavor. Consider what fermentation does to soy beans: soybeans and tofu are pretty bland, and are commonly used only as a substrate for sauces and other flavors, but once fermented, they become the basis of some of the most savory ingredients ever—miso, doenjang (Korean style fermented bean paste), and soy-sauce. Fermentation is also what gives bread and wine and beer their depth of flavor compared to their unfermented ingredients.

Fermentation also has the added benefit of up-converting carbohydrates into vitamins and increasing the nutritional density of many foods. Consider kombucha; the tea and the sugar used to brew kombucha have no nutritional value besides empty calories, but after fermentation, kombucha is a rich source of B vitamins. Cabbage becomes more digestible and also sees its vitamin content increased by the process of being fermented into sauerkraut and kimchee. The microbes that carry out fermentation need these vitamins, but also have the metabolic pathways to make their own from the starches and sugars present in the food, whereas we do not. We merely benefit from them pre-processing the food.

Now that we understand what's going on when we ferment, let's see this optimized method for making kimchee. Get some friends together and have a kimchee making party, and perhaps get some Korean food and a bottle of soju afterwards.

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[1] This is a paraphrase of an observation on the discovery of penicillin from Cracked.com.

Step 1: Equipment for Making Kimchee

(Note: Please see the photos in every step; a lot of them have attached notes.)

Please obtain the following equipment. Be sure to check the photos, which have notes about these.

Food processor
Mesh strainer
Adjustable mandoline slicer (cut-proof gloves are recommended as well)
Salad spinner

Unusual items

one 5 liter fermentation jar
pickling weights for a 5 liter crock (these need to be sterilized)
two large basins

Explanation of the unusual items

5 liter fermentation jar

You can obtain these fermentation jars at Korean markets. Make sure you get the one which has a lid with a moat, which serves as the air lock when water is added. The air lock lets carbon dioxide burp out of the jar as the kimchee ferments, but prevents mold spores and airborne bacteria from infiltrating the fermentation vessel. The method used since ancient times has been the moat filled with water, which is simple and effective.

These fermentation jars cost about $10 at the Korean markets in the San Francisco Bay Area, and come in sizes as small as a pint to as large as 20L for about $24. Do you realize how affordable this is? Even the Perfect Pickler™ mason jar fermentation kits (for 1-2 quart jars) costs twice as much. The home brew supply stores don't even sell fermentation vessels at the prices you can get at the Korean markets. I got my fermentation jar at Kukje market. An equivalent stoneware fermentation crock with an air lock moat in which the lid rests (the traditional European design) typically costs between $80 and $200. For the price of the typical European style pickling crock, you can get ten of these jars and fill your pantry with pickled goodies. Besides being far less expensive, there are several reasons why I like the glass fermentation jar better.

These jars each come with a sturdy nylon jar sling, which makes them much easier to move around compared to a stoneware crock. With the nylon jar sling, you can easily move the jar into and out of your refrigerator, your pantry, or your fermentation room (if you're an enthusiast), or even take your kimchee to parties and potlucks.
Clear glass is totally inert, and guaranteed to be non-reactive. The glaze on stoneware may or may not contain lead or cadmium, which are toxic; you need to test any crock you buy to be sure. Some potters simply don't know with certainty what's in their glaze.
Glass is transparent. I can see how my veggies are fermenting and marvel at the bubbles forming before my eyes, and can estimate how well fermented my food is without opening the lid and potentially contaminating the food.
The lid screws on, and the air lock cap can be swapped with the storage cap for refrigeration. Stoneware crocks don't have this feature.

The Korean markets also have smaller quart and pint sized fermentation jars with air-locks built in, all for surprisingly low prices. These work just as well for small pickle batches, and don't require as much overhead space as the water trap air lock mason jar conversions. If you are serious about fermenting vegetables, go to the Korean market or housewares store, and buy yourself a trunk-load of these jars. I don't think you'll find a better value anywhere for fermentation jars.

Large basins

In the photos, you'll see a couple of large stainless steel basins. These are not merely large kitchen prep bowls; the large one is more than double the capacity of the largest bowl could find at the cooking supply store. I got these at the Korean market for $30 and $40 respectively. They have them in stainless steel, aluminum, and plastic. I prefer stainless. I don't know of any other markets that sell large basins like these. These are used for salting the cabbage for kimchee, and perhaps for bathing small children. Get the largest basins you can; I originally only had the smaller of these two basins, and it proved to be too small; I was loosing bits of cabbage from the undersized basin as I tossed the cabbage to distribute the salt.

Fermentation weights
These are variously known as pressing stones, fermentation stones, or pickling weights. These are not traditionally used in the Korean method for making kimchee; these are from the European pickling tradition. The purpose of these weights is to keep the vegetables under the brine during fermentation, because mold cannot easily grow on liquids, and where it manages to grow on the surface, it can't easily send hyphae (mold roots) into the liquid. Keeping your sauerkraut or kimchee submerged under the brine is the best way to protect it against mold. I really like this optimization, and have adapted this for my kimchee method. If you don't use fermentation weights to keep the kimchee submerged, white mold may form on the bits that are sticking out of the liquid. There may even be some surface mold on the liquid. Do not be alarmed; the white molds that are able to withstand the acidity of the brine are not harmful; they're just not the kind of fermentation we're trying to promote in kimchee. Pick off or skim off any white mold and dispose of it, and carry on. However, if you get green or black or other colored molds, you should probably discard your kimchee and start over.

Fermentation weights come in a couple of styles. There are circular ones that are about 2"-3" in diameter made of glass or stoneware which are intended for weighing down vegetables being fermented in canning jars, and larger half-circle stones which are much heavier, intended for pressing down sauerkraut in a fermenting crock. The large half-circles are the ones you need for this project. I obtained mine from Amazon for about $22. (I later found these for $7 at Williams Sonoma, which was rather surprising. It's not often that you find things at Williams Sonoma that are a fraction of the cost of the same at Amazon.) These fermentation weights are sized for a 5 liter fermentation crock, and fit my inexpensive glass fermentation jar perfectly.

Sterilizing your fermentation weights

The fermentation weights that will fit your 5 liter jar are likely to be made of unglazed stoneware, and must be sterilized. Because the stoneware is porous, it could harbor unwanted microbes, which could form colonies and get a head start before the beneficial bacteria become thoroughly established enough to ward off competing microbes. To prevent any unwanted microbes from contaminating your kimchee, wash all your jars and bowls and food processor with hot water and dish soap. The fermentation weights, however, ought not be washed with dish soap because they are porous, and may hold onto soap residue that will ruin the flavor of your kimchee. It is sufficient to wash them with water before sterilizing them. I have not found it necessary to do a full sterilization of the jar, its lid, the basin, etc. because these surfaces are not porous.

Steam is superior to boiling for sterilization

I find that for sterilizing things for fermentation, steam is advantageous for the following reasons:

You can steam-sterilize anything from a single fermentation stone to a whole set of tools using just a pint of water. As long as the steam can reach its surfaces, it can sterilize the germs that are on those surfaces. This saves water, which is important for areas under drought conditions. (At the time of this writing, California is suffering from its worst drought in recent history.)
It takes very little time and energy to boil the small amount of water that it takes to steam your tools. For sterilizing my fermentation weights, it took less than 1 pint or so; enough to cover the bottom of your pot by 1/2" should be enough. Compare that with how much time and energy it takes to boil enough water to cover all your tools; why waste more time, gas, or electricity to do the same job? A pint of water comes to a boil in about a minute.

When water vapor condenses on something in the course of steaming, it not only happens at boiling temperature, it also imparts the quantity of energy it took to vaporize the water. Because of this, steam cooks any unwanted microbes to death very rapidly. Five minutes of steaming is more than enough. Leave your fermentation stones to cool with the lid on; by the time you are ready to use them, they will be cool enough to handle.

Step 2: Ingredients for Making Kimchee

Produce

I stuck to simple ratios; kimchee is pretty forgiving, and natural ratios are the most convenient to work with anyways.

Three small Napa cabbages, or two medium ones. The ones pictured are small.
one bunch of scallions
one bunch of Lacinato kale (I haven't tried using curly kale, but I don't think it has the right texture.)
one daikon radish (I use the green top variety, since this is what the Korean markets sell.)
one head of garlic, two if you really like garlic
one onion
two asian pears (or one large one; the ones at the Korean market tend to be huge; we will only be using one and a half of the ones shown in the photo.)

Napa cabbage is also known Chinese cabbage (大白菜, literally "big white vegetable"), which is popular throughout east Asia. In Japan, it is known as Hakusai, and in Korea it is known as Won Bok. The Napa cabbage that I got at Berkeley Bowl was relatively small compared to the ones at the Kukje market. At the Kukje market, the Napa cabbages were the size of watermelons.

The asian pear provides some sugar to help with the fermentation process. Alternatively, you can use one and a half teaspoons of sugar.

Other ingredients

1/2-3/4 cup of Salt. Use kosher salt or sea salt; regular iodized salt is unpleasant.
Fish sauce. You'll be using between 1/3 cup and 3/4 cups
Korean red pepper flakes. You'll need about a cup of this.
Salted tiny shrimp (I'm guessing these are the same things as krill). About two teaspoons per 2 pounds of cabbage.

Fish sauce, tiny salted shrimp, and the Umami flavor

Fish sauce and salted shrimp may seem like odd things to add to fermenting cabbage. (In fact, this kimchee recipe is technically not vegetarian because of these ingredients.) Indeed, if you taste or smell these ingredients on their own, they are extremely intense and even pungent or fishy to the point of being unpleasant. However, when added to a large quantity of cabbage to be fermented into kimchee, they add a distinct dimension to the flavor that cannot be achieved without ingredients that impart glutamate. The fish sauce and the tiny salted shrimp add the flavor known as umami, which our tongue actually has the capacity to taste. For those who are not familiar with this flavor, umami can be best approximated by the word "savory". The flavor itself is carried by the neurotransmitter glutamate present in certain foods, and by nucleotides present in our food. Food items which are more familiar in western cuisines such as parmesan cheese, tomato paste, stewed meat, egg yolks, and anchovies are rich in glutamate. When tasted, this neurotransmitter jumps up and down on your tastebuds and screams "FLAVOR! FLAVOR! FLAVOR!" and enhance the other flavors in the food.

You've probably heard the term 'glutamate' in the context of monosodium glutamate, a.k.a. MSG, which is a salt made from glutamate extracted from yeast or kelp. (It is only in the form of a salt when dry; as soon as it contacts water, it dissociates into sodium and glutamate.) Using MSG to put glutamate into your food in order to get that savory taste is cheating. Real good cooks know how to find natural sources of glutamate by picking great ingredients. Glutamate is not bad for you in the quantities that naturally occur in food (which can be quite a lot); you cannot be allergic to the most common neurotransmitter in your body.

The spices, added flavors, and umami aspect of kimchee are what really set it apart from sauerkraut. Under conditions of scarcity where I might not have anything to eat but pickled vegetables, kimchee is flavorful enough that I could probably subsist on kimchee and rice without getting too bored. I have a hard time imagining myself doing the same with sauerkraut.

Step 3: Cut Up the Cabbage and Kale and Wilt the Leaves With Salt

Overview

Unlike sauerkraut, which ferments in its own juices which are drawn out with salt, kimchee involves wilting the cabbage and discarding the juices drawn out by salt, and substituting in other fermentables in the form of a flavored paste that is rubbed into the cabbage. Because of this step, kimchee is denser than sauerkraut, and somewhat drier. The flavor is correspondingly more intense. It also ferments faster.

If you've ever followed some of the kimchee recipes for those mason jar pickling kits, they usually recommend putting your veggie mix into the jar and topping it off with brine. This is the wrong way to do kimchee; do not do this. Or if you do, at least don't call it kimchee. The proper way is to wilt the leaf matter with salt, discard the brine, and to rub in a flavored paste.

Cut up the cabbage and pick the layers apart; remove bug bitten parts
Cut up the kale into thirds, and remove the central vein; remove bug bitten parts
Toss the vegetables with 3/4 cups of salt and leave to wilt for 2-3 hours, mixing once every half hour to distribute the brine

Cut up the cabbage and pick the layers apart

Set aside 1/2 to 3/4 cups of kosher salt or fine sea salt. This does not represent how much salt ends up in the kimchee; you will be rinsing off the cabbage after it has wilted.

Cut the cabbage in half, and then in quarters, cutting along the length of the cabbage. Then, cut each of those quarters into four or five segments. The very bottom segment will have the heart of the cabbage, where all the leaves are attached. You will need to cut the cabbage heart out.

Pick out any portion of leaves that look bug bitten. You need not discard the whole leaf. Don't be alarmed at a few leaves having a few munches; this is virtually unavoidable with napa cabbage. In fact, I would be a bit suspicious if the cabbage had absolutely no bug bites unless the cabbage was grown in a hydroponic greenhouse. Having absolutely no bug bites would suggest to me that perhaps a lot of pesticides were used. If your cabbage is badly bug-eaten, toss it and get another, but a few munches on a few of the outer leaves is not a problem.

The layers of the cabbage are going to be naturally stuck together. Pick the layers apart over your large basin, and sprinkle a bit of salt each time you add more cabbage to the basin.

Cut the kale and remove the central vein

Give your kale a quick wash with water, then cut your lacinato kale into thirds, and use your hands to peel the leaf matter off of the stiff central vein, which has an unpleasant texture. Tear off any bits that are bug bitten, or which might have bugs hiding on the underside. (This is not uncommon, but it is also nothing to be alarmed about. Kale is good stuff, and the bugs instinctively know this.) Tear any large pieces into more bite sized pieces, and put all of this in your basin. As I mentioned before, in my opinion, curly kale doesn't have the right texture for kimchee; Lacinato kale (also known as Tuscan kale or dinosaur kale) is more suitable.

Toss the vegetables with salt and leave to wilt for 2-3 hours

Toss the kale and cabbage leaves together with the remaining portion of your salt to distribute the salt evenly. I used about 3/4 cups of salt for three small Napa cabbages; as long as you don't use an excessive amount or too little, this step is fairly tolerant of variations of up to a quarter cup in the amount of salt you use to wilt the cabbage; at the end you will be rinsing off the excess salt. Leave the cabbage and kale to wilt for 2-3 hours, tossing the mix a couple of times in the process. After about an hour, a lot of moisture will have been drawn out of the cabbage, forming a brine that collects at the bottom of the basin. Toss the cabbage and kale to coat the pieces that are under-wilted with this brine; this will ensure even wilting. The longer you let your cabbage wilt, the more moisture will be drawn out. Give the cabbage no less than 2 hours; 3 hours will give you a more complete wilting.

While the cabbage and kale are wilting, you should prepare the rest of the vegetables and the flavored paste for the kimchee.

Step 4: Cut Up Your Scallions and Set Them Aside

Trim off the roots of the scallions, and cut them into 1.5 inch long pieces. I like to cut a split into the white portions of the scallions so the flavor paste can get into these.

Set all these aside for later. The scallions need not be wilted, so don't toss them into the bowl with the salted cabbage.

Step 5: Julienne the Daikon Radish

Daikon matchsticks have a slight root vegetable crunch and have a mild sweetness. Cutting them into matchsticks gives the daikon a nice texture and mouth-feel, and increases the surface area to volume ratio, which makes it faster to ferment the pieces all the way through.

I'm a bit obsessive about the craftsmanship of whatever I make, so I go to a bit more trouble to produce a consistent matchstick cut.

Note: The daikon I obtained was way larger than what I needed for this recipe. I only ended up using about a quarter of it. If you really like daikon, feel free to use more. If you use the whole thing, it won't all fit into the jar with enough room for the fermentation weights.

My method: use mandoline slicer, followed by manual slicing

I used a mandoline slicer to slice a few layers off the daikon to give it a flat side so it wouldn't roll around on the cutting board, then I cut it to a square cross-sectioned billet. (If you can't do this easily with a chef's knife, plane the daikon down to a square cross-section using the mandoline.) I then I sliced the daikon billet into uniform slices with the mandoline set to make 3mm slices. I then stacked up the slices and cut them into matchsticks by hand. This is pretty labor intensive. Be very careful with the mandoline; wear cut-resistant gloves if you need to. It is very easy to injure yourself with these.

Set this aside in a bowl; we will mix this with the rest of the ingredients later.

Mandonline tip: Turn whatever you're slicing 180˚ every few slices

When using the mandoline, after every few slices, turn the thing you're slicing 180˚ to slice it from the opposite direction. You should do this because most mandolines have an angled blade, and the planing platform has a bit of flex to it; these two factors cause the slices to have a subtle wedge shape due to the bias in the cut. This bias is in two directions; the flexibility of the planing platform introduces a bias that goes up-down, and the angle in the blade introduces a bias that goes left-right. Every couple of 180˚ turns, turn whatever you're slicing 90˚ in order to cancel out the bias in the left-right direction as well.

If you don't reverse the direction of the cut once in a while to correct for the slicing bias, you'll find that the surface of the cut will become more and more angled, resulting in wasted material at the end which is too angled to get the beautiful consistent slices that you're using mandoline to achieve to begin with.

Shortcut: use a julienne peeler or a daikon lathe

I don't have either of these tools, but if you do, save yourself some labor and use these to cut your daikon into little strips. The daikon lathe will reduce your daikon into long square cross-sectioned filaments very rapidly. You should use a knife or scissors to cut this daikon floss into shorter segments about 2-3" long. (Japanese restaurants use the either this kind of lathe or a rotary daikon shredder to make that daikon floss which they use as a garnish.)

Step 6: Prepare the Sauce

The kimchee sauce is a blended paste consisting of pear, onion, garlic, salted shrimp paste, fish sauce, and Korean red pepper flakes. The steps involved can be pretty succinctly summarized:

Wash, cut, and core one pear, then cut into chunks
Peel and cut the onion into chunks. Remove root portion.
Peel 6-8 cloves of garlic
Put all of the above and 2 tsp. of salted shrimp into the food processor. Pulse the food processor until a coarse paste is formed, then process on full power until the coarse paste becomes a fine paste.
Transfer the paste to your other large basin, and add 2/3 cup of fish sauce (or as much as 3/4 cup, if you like extra savory kimchee) and 1 cup of Korean red pepper flakes. Stir all of this together until evenly blended.
Mix the daikon and scallion with the sauce in the basin.

Note: in the photos, I bought two heads of garlic, but I peeled one whole head and used every single clove in the sauce. This proved to be too much garlic; the flavor was not as balanced as a good kimchee should be, and was overly dominated by the garlic notes. Eight of the outer cloves of one head of garlic should suffice.

Note: I used one and a half small Asian pears, but if you happen to have one of the large ones, one should suffice.

Garlic peeling trick

If you need to peel a lot of garlic, as you would for this recipe, do this trick. You can peel a whole head of garlic in a few second this way. I attempted to do this with smaller bowls, and it didn't work as well. Larger metal bowls work best. Peeling your own garlic is a lot cheaper than buying pre-peeled garlic, and the garlic will be fresher.

Best way to core a pear: use a mellon baller

In the photos for this step, I used a paring knife to cut the core out of the pear, because I didn't have my preferred tool for the job on hand. The fastest and least wasteful way to core pears and apples is to use the large end of a mellon baller, as shown in this video.

Pear, onion, and garlic serve as fermentation boosters

Observe that the pear, the onion, and the garlic used in kimchee are food-processed into a paste rather than kept in identifiable chunks. This is because these ingredients serve as fermentation boosters, and work best in this capacity when blended into a paste. When this paste is spread on all of the vegetables, the sugars in the pear and prebiotic fiber in the onion and garlic feed the probiotics in the cabbage and help them rapidly multiply and dominate the kimchee. The sugars in the pear also feed some of the yeast present in the cabbage; the trace amounts of alcohol produced by the yeast are then converted into flavorful acids by the bacteria.

Remember my description of fermentation as human intervention into a three way war between yeast, bacteria, and molds? Think of these fermentation boosters as reinforcements that we send to the bacteria and the yeast. Consider the fact that Kimchee ferments to readiness in about a week, whereas sauerkraut takes several weeks to a month or so to finish fermenting. I suspect the use of the fermentation boosting effect of the pear/onion/garlic paste in kimchee may be the reason behind the difference in fermentation time.

Note: if you watched the "Kimchi Party" video that's been going around, you may have noticed that their recipe included a paste made of rice powder. I suspect this is also a fermentation booster. I wouldn't know how much rice powder to use, and none of the recipes that I've found included this ingredient. My recipe worked out quite well without it. Their recipe also uses pineapple instead of Asian pears. I've also seen apples or just a couple of teaspoons of sugar used as the sweet portion of the fermentation booster. Feel free to experiment with variations after you've made a classic version with one of the traditional fermentation boosters to get a sense of what the classic version tastes like; Don't go making blueberry banana kimchee with your first batch and complain that the flavors clash.

Step 7: Rinse Brine Off of Cabbage and Kale, Then Spin-dry

After two hours of wilting, the cabbage and kale should be limp from having given up a lot of moisture. If you taste a piece from the bottom of the basin, where all the brine accumulates, you'll get a sense of how salty it is. A bit of the salt diffuses into the leaves, but the rest of it, contained in the brine, must be rinsed off, or the kimchee may end up too salty. Before seasoning the veggies with the sauce you prepared in the previous step (which contains some salt from the fish sauce and the salted shrimp), rinse the excess salt from the veggies, and spin-dry them with the salad spinner. The best way to rinse the cabbage thoroughly is to use a mesh strainer to hold the cabbage and kale under running water while fluffing the leaves with your hand. (I used a pot of filtered water for the rinse as you can see from the photos because the tap water where I made this batch did't taste good.) You may need to drain the salad spinner between each load; a lot of water comes off in this step.

You may have noticed that we didn't wash the cabbage or kale in the prior steps. This is because this stage pretty much is the washing stage.

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Note: Make sure you have clean hands for this step. Thoroughly wash your hands with hot water and soap. You don't want to infect your kimchee with some germ that may get a foothold as it all starts to ferment.

Step 8: Mix Sauce With the Veggies

As you spin-dry a grip of your wilted vegetables, put the dried vegetables in the basin with the sauce, daikon, and scallions. Once all your vegetables are in that basin, use your hands and mix all of them together so that every piece of cabbage and kale is coated with sauce. If you come across any clumps of daikon or cabbage, break up the clumps and make sure the sauce is evenly distributed; you want all of the fermentation boosting goodness to be all over that cabbage so it gets a good vigorous start.
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Step 9: Stuff Mixture Into Fermentation Jar and Add the Fermentation Weights

Minimize air bubbles as you stuff the mixture into the jar

Stuffing the combined ingredients into the jar is not as simple as just jamming it in their if you want to do things optimally. Remember; we're trying to get a nice cap of liquid over the kimchee, and we also don't want any air bubbles in the mixture at the beginning. Bubbles of carbon dioxide will form as the fermentation progresses, but our objective is to initially press all the air out because we want the beneficial bacteria in the cabbage to quickly dominate the kimchee, while suppressing mold. Mold cannot grow under liquid; mold needs a surface to grow on.

To do this, I pour some liquid from the bottom of the basin of the sauced mixture into the jar before pushing the vegetables into the jar. As I stuff the vegetables in, I push it down with my fist to force any air that may be trapped between the leaves to bubble out; the liquid re-settles and fills most of the voids.

(I recognize that not everyone optimizes this process as much as I'm trying to, but I don't want to do anything risky when fermenting. I imagine one bad batch could cause you to be turned off to fermenting your own foods, and that would be a very unfortunate thing.)

Add the fermentation weights

The level of the vegetables should not go higher than the shoulder of the jar. You should have at least an inch and a half of clearance under the shoulder for the fermentation weights. If you have too much kimchee to fit in the jar with enough clearance for the weights, feel free to eat whatever won't fit. (Or use a smaller fermentation weight that sits in the neck of the jar.)

Take your fermentation weights (which should be sterilized and cooled down by this point) and insert them one half at a time into the jar. Move the first one you insert towards the sides of the jar to make room for the second; it may be a tight fit. Top the whole thing off with sauce; use a soft spatula to scrape down every last drop of sauce from the basin if you must. Push the weights down and push all the sauce into the low spots until all of the vegetables are submerged in liquid. The weights themselves need not be totally submerged.

Step 10: Cap the Jar, Insert Jar Into Jar Sling, Then Prime the Air Lock

After you've wiped down the threads of the jar, screw on the large lid, then screw on the air lock cap.

Put on the jar sling

Before you put on the jar sling, untwist any straps that are twisted or tangled, and be sure to position the sling with the perimeter strap on the outside. Put the jar roughly over the middle (it doesn't matter if it the jar sits over part of the perimeter strap), and pull up on the handles while pushing down on the jar. Then, turn the jar 90˚ and pull the perimeter strap up to make sure the sling is snugly fitted on the jar.

The perimeter strap must be on the outside to ensure a tight fit; if you have the sling inside out, the vertical straps won't push out on the perimeter strap, and the sling will sag.

Prime the air lock

Once the jar sling is fitted, transport the kimchee to where you're going to leave it to ferment before priming the air lock; transporting the jar with water sloshing around in the moat of the airlock is annoying. (I like to observe my kimchee because I'm fascinated by these things, so I leave mine on the counter top.) Once in place, prime the moat around the air lock with a little bit of water; you only need enough water to cover over the holes at the base of the air lock with enough to compensate for a bit of evaporation. Having too much water in the air lock just makes it a messy hassle to open the jar later on.

The air lock lets the gases produced during fermentation bubble out while preventing flies and mold spores from getting into the jar. This serves the same purpose as the water filled moat on the European style stoneware fermentation crocks. As fermentation begins, you will occasionally see air bubbles burping out.

Step 11: Let It Sit for a Week to Ferment, Then Enjoy Your Kimchee!

Leave your kimchee to ferment at room temperature for a week. The primary change in the character of the kimchee imparted by fermentation is acidity; the kimchee develops a slightly sour flavor (roughly akin to sauerkraut) and more complex fragrances than were there before fermentation. Also, the somewhat tough crunchy parts of the cabbage become much more tender.

At that point, you have several options:

You can remove the fermentation weights and start serving it as a side dish, while re-capping it after each time you access it, letting it continue to ferment. As it continues to ferment, the flavor profile changes. It gets a bit more sour, and the flavor changes in ways that are subtle and hard to describe.
You can remove the fermentation weights, and swap the air lock cap for the sealing cap, then refrigerate your kimchee, and serve from the jar as needed

How long does kimchee last?

Honestly, I don't know from experinece how long home made kimchee lasts. No batch that I've made and kept around has had anything left beyond a week. However, based on the fact that some of the über traditional methods leave the kimchee fermenting for over a month unrefrigerated, I suspect it will last at least that long; refrigerating it is likely to make it last even longer. Do keep in mind that really old kimchee is likely to be very sour. If anything, that acidity is probably why it doesn't spoil.

What can you do with your kimchee besides eating it as a side dish?

Chop it up and use it as the vegetable portion of your Asian dumpling stuffings.
Make savory kimchee pancakes. (I will make an instructable for this one of these days.)
Chop it up and serve it with sausages on a bun as a substitute for sauerkraut.
Make kimchee stew, a traditional Korean dish.

Conclusion

I hope you enjoyed this instructable and the primer on fermentation. Remember: may other things can be fermented. It is a healthy, delicious, and low-energy way of preserving your food without refrigeration. Feel free to take some of the techniques from this instructable and apply them to other vegetables you want to pickle.

Introduction: Kimchee Party! a Recipe and a Primer on Fermentation

The secret to food preservation: Make food inhospitable to microbial decomposers

How fermentation preserves food:One form of filth kills another form of filth