Water Bath Canned Homemade Sauerkraut
Do you know what I find super fascinating? Fermentation! That is what I think is so cool about making sauerkraut from scratch.
You start with a few heads of cabbage, sprinkle it with salt, pack it into jars, and then let time do the work. No vinegar or special preservatives are added. In fact, the whole process relies on naturally occurring bacteria already present on the cabbage.
Cabbage is a low-acid vegetable, so fresh cabbage is not naturally acidic enough to safely can using a boiling water bath. However, fermentation changes the cabbage completely. The salt creates the right environment for beneficial lactic acid bacteria to take over, and those bacteria convert natural sugars in the cabbage into acids. As fermentation progresses, the pH drops dramatically.
That means you can take fresh cabbage, add the proper amount of salt, give it enough time under the right conditions, and end up with a naturally fermented food that is much more acidic. Science in the kitchen is so much fun!
Once the sauerkraut has fully fermented, you can enjoy it fresh from the refrigerator, freeze it, or water-bath can it for longer-term shelf-stable storage. This recipe walks through the fermentation process first and then shows you how to safely can the finished kraut.
Why Make Sauerkraut at Home?
Homemade sauerkraut tastes completely different from commercial varieties.
You’re the scientist that is in charge of the cabbage, the salt, the fermentation time, and the final texture. Plus, if you grow cabbage in your garden, this is a super rewarding way to preserve a big harvest before those beautiful heads start taking over every available inch of your refrigerator.
Sauerkraut also gives you a great lesson in food science.
Fresh cabbage contains natural sugars. Lactic acid bacteria use those sugars during fermentation and produce lactic acid along the way. As that acid accumulates, the pH of the cabbage drops. Eventually, the environment becomes acidic enough that fermentation naturally slows and stops.
According to Extension guidance, fully fermented sauerkraut should be tart, firm, and free from mold, slime, or unpleasant odors.
So, yes, you are basically creating a controlled little ecosystem inside your fermentation jar.
And cabbage is doing most of the work.
The Most Important Ingredient: Salt
The salt in sauerkraut is not just there to make it taste salty.
It is a necessary part of the fermentation process.
For a tested sauerkraut recipe, the recommended ratio is 3 tablespoons of canning salt for every 5 pounds of shredded cabbage. The salt helps create conditions that favor desirable bacteria while discouraging the growth of unwanted microorganisms.
That is why I recommend weighing your shredded cabbage rather than simply counting cabbage heads.
Cabbage heads can vary dramatically in size. Five small heads could weigh very differently from five enormous garden cabbages. So according to this recipe, ¾ cup of canning salt equals 12 tablespoons, so that amount corresponds to approximately 20 pounds of shredded cabbage using the 3-tablespoon-per-5-pound ratio.
If your five cabbages weigh more or less than that, adjust the salt accordingly.
Also, use canning or pickling salt rather than trying to eyeball the amount with a different type of salt. Flaked and kosher salts can vary in density, so volume measurements are not necessarily interchangeable.
Do not reduce the salt in this recipe. In fermented sauerkraut, the salt contributes to the safety of the fermentation rather than simply providing seasoning.
The Science Behind Sauerkraut Fermentation
This is the part I find fascinating.
Fresh cabbage is not an acid food. Its natural pH is too high for safe boiling-water-bath canning. If you simply shredded fresh cabbage, packed it into a jar, and processed it in a water bath, that would not turn it into a safe shelf-stable canned vegetable.
Fermentation changes that equation.
Once the cabbage is shredded and salted, the salt begins drawing water from the cabbage. You massage and pack the cabbage, and eventually that liquid becomes the brine surrounding the shredded cabbage.
At the same time, naturally occurring lactic acid bacteria begin fermenting the sugars in the cabbage.
As they work, they produce lactic acid.
That acid lowers the pH.
As the fermentation continues, the cabbage becomes increasingly acidic. Extension guidance recommends confirming that a ferment reaches a pH of 4.60 or lower before considering the fermentation complete for preservation purposes.
This is why the process is so interesting from a food-preservation standpoint. You are not adding vinegar to make the cabbage acidic. Instead, you are allowing fermentation to produce the acid naturally.
Salt + cabbage + the right environment + time = fermentation.
That little combination completely changes the chemistry of the cabbage.
Temperature Matters More Than You Might Think
If you have ever made sauerkraut and wondered why one batch took longer than another, your room temperature is most likely the answer.
The recommended fermentation temperature is around 70°F to 75°F. At that temperature, sauerkraut generally takes about 3 to 4 weeks to fully ferment.
However, cooler temperatures slow the process.
At approximately 60°F to 65°F, fermentation may take around 5 to 6 weeks. Below about 60°F, fermentation may become very slow or may not proceed properly.
On the other hand, warmer temperatures speed things up.
That sounds convenient, but hotter is not better. Temperatures above roughly 75°F can produce softer sauerkraut, while temperatures above 80°F increase the risk of spoilage and undesirable microorganisms.
So don’t look at the calendar alone.
A jar sitting in a 72°F kitchen for three weeks is experiencing a very different fermentation environment than a jar sitting in a 62°F basement for three weeks.
The air temperature changes the speed of the microbial activity.
That means your sauerkraut might need more or less time than mine.
What Happens If Sauerkraut Doesn’t Ferment Long Enough?
This is where patience really matters.
If the cabbage has not fermented long enough, it may not have developed enough acidity. The flavor will usually be less tart, and the fermentation may still be active.
More importantly, you should not assume that a specific number of days automatically means your sauerkraut has reached the desired acidity.
A pH meter can give you additional information when you are specifically monitoring acidity. Extension guidance recommends a pH of 4.60 or lower, along with the other signs of completed fermentation.
If your sauerkraut is still bubbling heavily, tastes only mildly fermented, or has not reached the desired acidity, give it more time under appropriate fermentation conditions.
Do not rush this part.
The entire point of fermentation is to give the beneficial bacteria enough time to produce the acids that make sauerkraut what it is.
What Happens If Sauerkraut Ferments Too Long?
Interestingly, fermentation does not simply continue getting more acidic forever.
As acids accumulate, they eventually create an environment where further growth of the fermenting bacteria becomes limited. In other words, the fermentation naturally slows down.
However, leaving sauerkraut sitting around for an unnecessarily long time can still affect quality.
Texture can become softer, and the flavor can become much more sour. Remember- temperature plays a role here, too. Warmer fermentation conditions can increase the risk of softening and spoilage.
The important thing is to look at the sauerkraut itself rather than deciding that “longer is always better.”
Finished sauerkraut should have a pleasant sour aroma, a tart flavor, and a reasonably firm texture. If you see mold, notice a rotten or unpleasant odor, or the cabbage becomes slimy, don’t taste it- toss it.
Keeping the Cabbage Under the Brine
This is another important part of successful fermentation.
The shredded cabbage must remain submerged beneath its brine. Keeping the cabbage below the liquid helps create the low-oxygen environment needed for fermentation and reduces the opportunity for surface mold to develop.
That’s why I use glass fermentation weights.
After packing the cabbage tightly into the jars, press it down firmly and add the liquid released during the salting process. Then place the weights on top.
As the fermentation gets going, you may see bubbling and movement in the jars.
Check the jars periodically and make sure the cabbage remains beneath the brine. Extension guidance recommends checking jar fermentations several times each week and removing surface scum or mold if it develops.
A fermentation airlock or pickle pipe is helpful because it allows fermentation gases to escape while limiting oxygen exposure.
And trust me, put the jars on a tray.
Sauerkraut has a habit of making its own little fountain when fermentation gets active.
How to Make Homemade Sauerkraut
Start with firm, mature cabbage.
Wash the cabbage, remove damaged outer leaves, remove the cores, and shred the cabbage fairly thinly.
Now weigh the shredded cabbage.
For every 5 pounds of cabbage, use 3 tablespoons of canning or pickling salt.
Place the cabbage in a large mixing bowl and sprinkle the appropriate amount of salt over it. Massage the salt thoroughly into the cabbage.
Let it rest for several minutes so the salt can begin drawing out the cabbage’s natural moisture.
As you work the cabbage, it should become softer and begin releasing plenty of liquid.
Pack the cabbage tightly into clean fermentation jars, pressing firmly as you go. Add all of the natural liquid from the bowl.
The cabbage should be submerged beneath the brine.
Place your fermentation weights on top, install the pickle pipes or appropriate fermentation covers, and move the jars to a cool, dark location.
Ideally, keep the temperature around 70°F to 75°F.
Now you just wait.
Fermenting for 3 to 4 Weeks
At the recommended temperature, plan on approximately 3 to 4 weeks.
If your room is cooler, you may need 5 to 6 weeks.
Don’t panic if your fermentation behaves differently from someone else’s. Temperature, cabbage variety, cabbage maturity, and other factors can affect the speed of fermentation.
Instead, watch the kraut.
You should see signs of fermentation, such as bubbling. The cabbage will gradually become more acidic and develop that unmistakable sauerkraut flavor.
Once fermentation has completed, check the finished kraut carefully before canning.
If you are using a pH meter, confirm that the ferment has reached pH 4.60 or lower.
Water Bath Canning Sauerkraut
Once your sauerkraut has fully fermented, you can preserve it by boiling-water-bath canning.
Transfer the fermented sauerkraut into clean canning jars, packing it firmly and covering it with its natural juices. Leave ½ inch of headspace.
Do not rinse the sauerkraut before canning to make it less salty.
That might sound tempting, but rinsing away the natural acidic brine can raise the pH and create a food-safety problem. If the finished canned sauerkraut is too salty for your taste, rinse it after opening the jar instead.
Remove trapped air bubbles, wipe the rims clean, apply the lids, and tighten the rings fingertip tight.
For this, what is called the raw-pack method, the tested processing time at 0 to 1,000 feet is 20 minutes for pints and 25 minutes for quarts. Processing times increase at higher elevations.
Once processing is complete, carefully remove the jars and place them upright on a towel-lined surface.
Let them cool undisturbed for 12 to 24 hours. Check the seals, label the jars, and store them in a cool, dark place.
Any jar that fails to seal should be refrigerated and used promptly.
Does Canning Kill the Probiotics?
Yes, heating fermented foods for canning changes what is alive in the jar.
The beneficial bacteria associated with raw fermented sauerkraut do not survive the high temperatures used during water-bath canning. Refrigeration or freezing preserves more of those live fermentation organisms.
So why can sauerkraut?
For me, it’s about preservation.
A big cabbage harvest can turn into jars of shelf-stable sauerkraut that you can pull from the pantry months later. If maintaining live cultures is your primary goal, refrigerated fermented sauerkraut is the better choice.
If your goal is long-term pantry storage, properly fermented and properly canned sauerkraut is the best way to preserve the harvest.
A Few Sauerkraut Tips
Weigh your cabbage. Five cabbage heads don’t tell you nearly as much as the actual weight of the shredded cabbage.
Measure the salt accurately. The salt ratio matters for both quality and safety.
Keep the cabbage submerged. The brine is your friend.
Watch your temperature. Around 70°F to 75°F is ideal. Cooler temperatures slow fermentation, while excessive heat can damage quality and increase spoilage concerns.
Give it enough time. A cool kitchen may require several additional weeks.
Don’t can unfinished sauerkraut. Fermentation needs to reach the appropriate level of acidity before you move on to canning.
Never taste questionable kraut. Mold, slime, or a bad odor means it should be discarded.
Don’t rinse before canning. The acidic brine is important. Rinse it after opening the finished jar if you want to reduce the saltiness.
Why I Love Making Sauerkraut
There are plenty of complicated preservation projects out there.
Sauerkraut isn’t one of them.
The ingredient list is almost ridiculously simple: cabbage and salt.
Yet that simplicity hides an entire little science experiment.
You shred cabbage. Salt pulls out its natural juices. Beneficial bacteria begin using the cabbage’s natural sugars. Acids are produced. The pH falls. The flavor changes. The texture changes. Eventually, you have a completely different food sitting in the same jar.
And then, if you want to keep it on the pantry shelf, you can take that finished fermented cabbage and preserve it through water-bath canning.
That is pretty incredible for two ingredients.
The biggest lesson is that time and temperature matter. A 70°F kitchen and a 60°F basement won’t give you the same fermentation timeline. Therefore, don’t blindly follow a calendar. Pay attention to the temperature, watch the fermentation, keep the cabbage submerged, and confirm acidity when appropriate.
Once you understand what is happening inside that jar, making sauerkraut becomes even more fun.
You are using fermentation to transform a fresh, low-acid vegetable into a naturally acidic food through one of the oldest forms of food preservation around.
And that, my friends, is some seriously cool kitchen science.
Frequently Asked Questions
How long does homemade sauerkraut take to ferment?
At approximately 70°F to 75°F, sauerkraut generally takes about 3 to 4 weeks. At 60°F to 65°F, it may take 5 to 6 weeks. Colder temperatures can slow fermentation significantly.
Can I ferment sauerkraut at 80°F?
It is not recommended. Higher temperatures can cause sauerkraut to soften and can increase the risk of spoilage. Aim for approximately 70°F to 75°F instead.
How much salt do I need for sauerkraut?
Use 3 tablespoons of canning or pickling salt for every 5 pounds of shredded cabbage. Weighing the cabbage is important because cabbage heads vary considerably in size.
Does sauerkraut need vinegar?
No. Traditional fermented sauerkraut does not need vinegar. The acidity develops naturally as lactic acid bacteria ferment the sugars in the cabbage.
Can I reduce the salt?
No. Do not reduce the salt in a tested fermentation recipe. Salt helps create the conditions needed for desirable fermentation and inhibits the growth of unwanted microorganisms.
How do I know when sauerkraut is done?
Finished sauerkraut should be tart and have a pleasant fermented aroma and firm texture. A pH of 4.60 or lower is an important safety benchmark when monitoring fermentation. If you see mold, slime, or notice a bad odor, do not taste it.
Can I can sauerkraut after fermentation?
Yes. Fully fermented sauerkraut can be preserved using a tested boiling-water-bath canning method. Follow the appropriate processing time for your jar size and elevation.
Does water-bath canning preserve the probiotics?
No. The heat used during canning destroys the live beneficial bacteria associated with raw fermented sauerkraut. Refrigeration or freezing preserves more of those live organisms.
What should I do if my sauerkraut is too salty?
Do not rinse it before canning. Rinsing removes some of the natural acids along with the salt and can raise the pH. Instead, rinse the sauerkraut after opening the properly canned jar if you want to reduce the saltiness.
Why did my sauerkraut take longer than three weeks?
Temperature is often the reason. Fermentation proceeds more slowly in a cooler room. At 60°F to 65°F, fermentation can take approximately 5 to 6 weeks instead of the typical 3 to 4 weeks at 70°F to 75°F.
More Canning Recipes
Pressure canned Corn
Water bath Canned Mandarin Oranges
Sauerkraut
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Equipment
- 3 2 quart mason jars
Ingredients
- 20 pounds Cabbage
- 3/4 cups Pickling salt
Instructions
- Wash the cabbages and cut into shreds.
- Place the shredded cabbage into a mixing bowl.
- Pour the salt over the shredded cabbage and massage the salt into the shredded cabbage. Allow to rest 5 minutes to draw out some liquid from the cabbage.
- Pack the shredded cabbage tightly into large 2 quart jars, packing down with the pickle pounder.
- Pour the liquid from the cabbages into the jars.
- Place the glass weights into the jars.
- Wipe the rims of the jars and place the pickle pipe on the rim. Tighten the band and store in a cool, dark place for 3-4 weeks. Monitor the jars occasionally to make sure the weights are holding down the cabbage below the liquid.
Canning the Kraut
- Fill the water bath and bring to a boil.
- Wash the quart jars, lids, and rings in hot soapy water.
- Transfer the fermented sauerkraut to the smaller jars, packing each tightly.
- Pour the liquid into the jars leaving 1/2 inch headspace. Remove any trapped air with the bubble popper and adjust headspace if necessary.
- Wipe the rims of the jars, place the lids, and tighten the rings finger tip tight.
- Using the jar lifter, lower the jars into the boiling water bath, cover, and process for 25 minutes.
- Remove the jars from water bath to a towel lined cutting board.
- Allow the jars to rest for 12 hours before labeling, dating, and storing. If any jars did not seal, refrigerate and use first.
Nutrition
