First of all, what is Fermentation?
People often think of beer or wine when they hear about fermentation, although the process extends to bread, cheeses, vegetables, yogurt, and beyond, and has been around since the beginning of the human era. At first, humans didn’t even know how it happened. In the East and in Europe, people gave thanks to the gods who changed watery juice to wine and rotting milk to something edible, neither of which agonized their stomachs like spoiled meat. Over time, we discovered the process behind the magic. Fermentation is the chemical transformation of organic substances into simpler compounds by the action of enzymes, which are produced by microorganisms such as bacteria, molds, or yeast. Liquid begins to bubble during the process due to the bacteria eating away at the sugars and releasing carbon dioxide into the air. Therefore, the word “fermentation” originates form the Latin and Sanskrit words for “boil”, which described how the ancient timers perceived what was happening. Fermented foods have lots of advantages over their original form. Not only are the end products often more digestible, they preserve vitamin and enzyme levels, replenish intestinal microflora, increase storage life, and contribute to overall good health.
Lacto-fermentation in a nutshell:
While certain yeasts are used to convert the sugars in grape juice or grains into alcohol, it is bacteria that are responsible for lacto-fermentation. Naturally occurring lactobacillus bacteria in plants have the ability to convert sugars into lactic acid. Lactic acid is a natural preservative that inhibits the growth of harmful bacteria, therefore being a probiotic in our guts.
Lacto-fermented sauerkraut recipe:
Sauerkraut is one of the easiest fermented power foods to make, with the fewest tools and ingredients. All you need is a fresh head of cabbage, salt, a large recycled pickle jar, rimmed pan for catching bubbling liquid, a saucer, or small plate, and a cool, shaded area to ferment, such as a pantry or cupboard. A kitchen scale and calculator will be useful as well since there is a specific salt to cabbage weight ratio. Cabbage will ferment naturally if left to its own devices, but its much, much safer to use salt in a specific quantity since salt keeps harmful bacteria at bay while the natural, good bacteria multiplies and takes over.
Below is a simple fermented sauerkraut recipe adapted from Serious Eats and Ball Complete Book of Home Preserving. The final product will store up to six months in the fridge. About two forkfuls of fresh live sauerkraut a day seem to be helping my finicky tummy stay happy, without the use of expensive, processed, store-bought probiotics. But, hey, if you have a German stomach of steel, go ahead and enjoy it with bratwurst, pork spareribs, and bratkartoffeln.- I won’t judge!
- 1 head of green cabbage, trimmed, cored, and thinly sliced or shredded, outer leaves reserved (see directions below)
- Diamond Crystal Kosher Salt; if using other brands, measure by weight and add more if needed (9.3g Diamond Kosher Salt : 1lb prepared cabbage. Link for Salt by Weight)*
- Caraway seeds
How much of each ingredient?
Weigh the prepared cabbage (the amount you’ll be using to make the sauerkraut).
*Every 1lb of shredded cabbage will require 9.3g Diamond Kosher Salt.
Add ¼ heaping tsp of caraway seeds for every 1lb of cabbage.
For example, 3lbs of cabbage will require 28g salt (3 Tbsps) and 1tsp caraway seeds.
For every 1lb of cabbage, you will need 1.25L of container, or jar.
For example, a 4L (4-quart) container is needed for every 5lbs (2.3kg) of fresh cabbage. You can use a stone crock or glass or food grade plastic container.
In a food processor fitted with a slicing attachment, in batches as necessary, cut cabbage intothin shreds, about 1/16 inch (0.2cm) thick. You can also do this with a sharp knife or mandolin. Remove any large pieces and discard.
If using a large fermentation crock, add shredded cabbage to crock, sprinkling in the measured salt and optional spices as you go. If using a large recycled pickle or olive jar, or a Ball jar (may need more than one), put shredded cabbage in a large mixing bowl and sprinkle with measured salt and optional spices. Mix well, then knead and squeeze cabbage for a few minutes to begin to release its liquid.
Covering cabbage between kneadings with plastic wrap or the crock’s lid, continue to squeeze and knead cabbage roughly every 15 minutes, until an ample amount of brine has formed; it should be enough to cover the cabbage when the cabbage is compressed. I’ve read that this can take up to 4 hours, but in my experience, it only took about 20 minutes with my cabbage pulled fresh from the ground. If not enough brine forms, proceed to the next step (you will add more brine later as necessary). If using a jar, pack shredded cabbage into jar now, with all its accumulated brine, leaving at least 4 inches (10cm) of space between cabbage and rim of container.
Lay reserved cabbage leaves on top of cabbage and press down until brine rises 1/2 to 1 inch above cabbage. Add stones (cleaned) and push down to compress even more. If there is not enough brine, top it up with a 2% salt solution. (You can make this by dissolving 2 grams of salt in 100 grams of water; 1 cup of water would require about 1 heaping teaspoon of Diamond Crystal kosher salt. Add water and salt to a saucepan, heat over medium-high setting, stirring to dissolve salt. Let cool to room temperature, then ladle over sauerkraut to cover. )
Seal fermentation crock with the airlock lid following manufacturer’s instructions. If you’re using a jar, put a small plate upside down on top of the jar opening. Put in a cool, dark place; 65 to 75°F (18 to 23°C) is ideal. After a day or two (or three), the fermentation process should kick off more actively and the cabbage should be bubbling away. If the vessel is quite full, it’s best to put a rimmed baking sheet under it to catch any overflowing fluids.
After the first week, feel free to open vessel, push cabbage back down below brine level (it’s very important that the cabbage always remain below the liquid level), and taste cabbage to monitor its progress. If brine gets low, top it up with more 2% salt water. Keep in mind that the more often you open the vessel, the greater the chance of mold growing on the surface. Every day, remove and discard any scum or mold that has formed on the surface and continue to ferment the kraut.
The sauerkraut is ready when it is quite sour, which can take anywhere from 3 to 6 weeks, depending on your preference. Don’t fret over the surface mold that you’ll scrape off the surface now and then, but throw out the sauerkraut if it becomes discolored, slimy, or malodorous. (Some sulfurous smell is natural, but anything truly offensive is a bad sign. Click here for a link on tips.) Refrigerate in sealed containers or its fermenting jar for up to 6 months.