Learn How to Prepare Sauerkraut From a Jar

Understanding Sauerkraut and Why People Prepare It at Home

Sauerkraut is cabbage that has been fermented through a process called lacto-fermentation, where natural bacteria break down the cabbage's sugars over time. The word "sauerkraut" comes from German and literally means "sour cabbage." This food has been consumed for centuries across many cultures, with records showing fermented cabbage dishes in China dating back thousands of years and in Europe for at least several centuries.

When you prepare sauerkraut at home, you're creating an environment where beneficial bacteria, primarily Lactobacillus species, naturally multiply and create lactic acid. This acid gives sauerkraut its characteristic tangy flavor and acts as a preservative. Historically, families fermented vegetables like cabbage to preserve the harvest through winter months when fresh produce wasn't available. Today, people prepare sauerkraut at home for several reasons: to control ingredients and avoid additives found in store-bought versions, to save money compared to purchasing prepared sauerkraut, and to understand the fermentation process itself.

Store-bought sauerkraut can cost between $3 to $8 per jar, depending on the brand and whether it's raw or pasteurized. When you make sauerkraut at home, the primary cost is cabbage, which typically costs $1 to $3 per head. A single head of cabbage yields roughly 1 to 2 quarts of finished sauerkraut. Learning to prepare sauerkraut from a jar means understanding how to transform a jar of raw ingredients into finished sauerkraut through fermentation.

Practical Takeaway: Home sauerkraut preparation offers cost savings and ingredient control. A single cabbage head costing $2 produces about 1.5 quarts of sauerkraut, reducing per-ounce costs significantly compared to retail prices.

Selecting Your Jar and Gathering Required Materials

The jar you choose for sauerkraut fermentation needs to meet specific requirements. The most important factor is that your jar can hold the cabbage submerged below its own liquid while allowing gases produced during fermentation to escape. Glass jars work best because they don't react with the acidic environment created during fermentation, unlike some metals or plastics. Avoid using jars with rubber seals designed for pressure canning, as these can trap excessive gas and create pressure buildup.

Recommended jar sizes for beginners range from one quart to one gallon. A quart jar (32 ounces) is manageable for first-time fermenters and ferments relatively quickly—typically 3 to 10 days depending on temperature. A half-gallon or gallon jar allows you to ferment larger batches but takes up more refrigerator space. Wide-mouth jars are easier to pack cabbage into and easier to remove finished sauerkraut from compared to narrow-mouth jars.

Beyond the jar itself, gather these materials before starting your fermentation:

• A clean cutting board and sharp knife for shredding cabbage
• A large mixing bowl for combining ingredients
• Sea salt or pickling salt (not iodized table salt, which can cloud the brine)
• Clean cloth or coffee filters to cover the jar opening
• A rubber band or string to secure the cloth
• Optional: a weight to keep cabbage submerged (a smaller jar filled with water, a ceramic fermentation weight, or even a clean cabbage leaf rolled tightly)
• A kitchen scale for measuring salt accurately

The salt-to-cabbage ratio is crucial. A standard fermentation uses 2% salt by weight of the cabbage. This means if you have 1 kilogram (about 2.2 pounds) of shredded cabbage, you'd add 20 grams (about 1.5 tablespoons) of salt. Measuring by weight rather than volume produces more consistent results.

Practical Takeaway: Use a wide-mouth quart glass jar, non-iodized salt, and a simple weight (water-filled jar works fine). Weigh your salt at 2% of your cabbage weight for reliable fermentation results.

Preparing Your Cabbage and Creating the Brine

Start with fresh, firm cabbage heads that show no signs of rot or damage. Green cabbage is most common for sauerkraut, though red cabbage and napa cabbage also ferment well. A typical medium green cabbage weighs between 1 to 2 pounds. Remove and discard any outer leaves that appear damaged or yellowed. Rinse the cabbage under cool water and pat it dry with a clean towel.

Cut the cabbage in half from top to root, then cut each half into thin shreds, roughly 1/8 inch thick. You can use a sharp knife, a mandoline slicer, or a food processor with a shredding blade. The thinner the shreds, the faster the fermentation occurs. After shredding your cabbage, place it in a large, clean bowl. You should have roughly 4 to 5 cups of shredded cabbage from a medium head.

Now calculate your salt amount. If you shredded 500 grams of cabbage, you need 10 grams (about 3/4 tablespoon) of salt. Sprinkle the salt over the shredded cabbage and begin massaging it vigorously with your hands. This step is critical—the salt draws water out of the cabbage cells through osmosis, creating a brine. Spend 5 to 10 minutes massaging the cabbage. You'll notice it becomes softer and moisture collects in the bottom of the bowl. This liquid becomes the brine that keeps your cabbage submerged during fermentation.

If the cabbage doesn't release enough liquid after 10 minutes of massaging, add cool, dechlorinated water a few tablespoons at a time until you have enough brine to cover the cabbage when packed into your jar. Some water sources contain chlorine, which can interfere with fermentation; letting tap water sit uncovered for several hours allows chlorine to dissipate. Alternatively, use filtered or boiled-and-cooled water.

Practical Takeaway: Cut cabbage into thin shreds and massage vigorously with salt for 5-10 minutes. This creates the brine that keeps cabbage submerged and fermentation proceeding smoothly.

Packing Your Jar and Managing Submersion

Transfer your salted, massaged cabbage and all its accumulated brine into your prepared jar. Pack it down firmly as you fill, pressing the cabbage below the surface of the brine. Continue packing until the jar is full but the cabbage is covered by at least one inch of brine. The goal is to keep all the cabbage material submerged below the liquid surface—cabbage exposed to air can develop mold.

If your cabbage isn't fully submerged after packing, add a bit more brine by mixing 1 teaspoon of salt with 1 cup of water. Add this solution until the cabbage is completely covered. The cabbage naturally wants to float as fermentation produces gases, so you need a weight to hold it down.

For weights, several options work well. A common method is to use a smaller jar (like an 8-ounce jelly jar) filled with water and placed directly on top of the cabbage. The smooth glass doesn't interact with the ferment, and the water weight holds everything down. Alternatively, ceramic fermentation weights designed specifically for this purpose can be purchased for $5 to $15. Some people use a clean cabbage leaf, rolled tightly into a plug and wedged over the top of the cabbage to hold it down. Avoid using anything metal directly touching the brine, as metals can react with the acidic ferment.

After weighting down the cabbage, cover the jar's opening with a clean cloth, coffee filter, or cheesecloth. This covering allows gases produced during fermentation to escape while preventing dust and insects from entering. Secure the cloth with a rubber band or string tied around the jar's neck. Don't use an airtight lid