Step 1: Cut
To make this basic sauerkraut, start by peeling away the outer layers of the cabbage to reveal unblemished, clean leaves. Rinse the cabbage and pat dry with paper towels. Reserve a few large leaves for covering the sauerkraut before storing.
Using a sharp knife, quarter the cabbage head. Remove the core and discard, or reserve the core to use in the sauerkraut, if desired. Carefully cut the cabbage into ⅛-inch to 1/16-inch slices.
Step 2: Salt
Place the shredded cabbage in a non-reactive bowl. Add 1 tablespoon salt to the cabbage and mix with clean hands or a wooden spoon. Salt helps release water from the cabbage, which becomes the brining solution. Add more salt, a little at a time, tasting occasionally to prevent over-salting.
Step 3: Pound
Working in small batches, transfer the salted cabbage to the fermenting vessel. Use a food-grade plastic container, crock or enamel pot that has been thoroughly cleaned and is free from any cracks or other imperfections — do not use anything metal. Pack the cabbage mixture down into the bottom of the container. Using a wooden spoon, non-metallic rolling pin, crock tamper or a very clean fist, pound the cabbage to release more liquid.
Continue this process using the remaining cabbage. Once all of the cabbage is in the container, continue to pound for about 10 minutes or until there is enough liquid to cover the cabbage by 1 inch. This process could take more than 10 minutes depending on the age of the cabbage — the older the cabbage, the less moisture it will have.
Step 4: Cover, Wait and Test
Next, cover and weigh down the cabbage using one of the following techniques: use a large inverted plate that fits snugly inside the fermenting vessel; place the reserved whole cabbage leaves over the sauerkraut and top with a heavy weight made for food use; weigh down the cabbage with a food-safe container filled with water; or completely cover the cabbage with a gallon-sized resealable plastic bag filled with a brine solution made of 6 tablespoons salt mixed with 1 gallon of water (brine is used as a weight in case the plastic bag leaks).
Cover the container with a clean kitchen towel or lid and store at room temperature — 68°F to 72°F — in a dark, well-ventilated area. Check daily to ensure the cabbage is still covered by the brining liquid. Skim off and discard any scum (yeast or mold) that forms on top.
The sauerkraut can take anywhere from 7 to 21 days to ferment. Taste it periodically to check fermentation and flavor. Once fully fermented, store sauerkraut in the refrigerator.