Since there have been ongoing debates about whether sauerkraut goes bad or lasts forever, you may wonder which of these claims is true.
Or, if you have bought or made some sauerkraut, you may want to know how to store it and tell if it has gone bad.
We have done some in-depth research and have come to the answers to these questions. So read on to learn more about the different types of sauerkraut, its shelf-life, storage requirements, making brine, and the signs of spoilage.
Pasteurized vs. Unpasteurized Sauerkraut
The fact that is that there are two types of sauerkraut – pasteurized and unpasteurized. This is the main reason for the confusion and debate about whether the sour cabbage goes bad or lasts indefinitely. And whether you should keep it in the refrigerator or let it sit at room temperature.
The unpasteurized type is alive and raw, contains probiotics, and continues fermenting. The pasteurized type has been cooked. As a result of the heat, it has stopped fermenting and doesn’t contain probiotics.
Since the unpasteurized live sauerkraut is continuously fermenting, it should be stored in the fridge. This helps slow down the formation and keeps it from becoming overly sour.
The pasteurized type doesn’t have live microorganisms in it because they are killed with the heat. This means it is shelf-stable and safe to store at room temperature if the jar or the can have not been opened yet.
In rarer cases, you may be able to find sauerkraut that is not completely pasteurized and which can be kept at room temperature until you open it.
In any case, if you want to take advantage of the health benefits of the probiotics in the sauerkraut, then you should opt for the unpasteurized type from the refrigerated shelves in the store.
Does Sauerkraut Go Bad?
The shelf-stable pasteurized sauerkraut will quickly go bad once you open the can or jar. It will last for up to a week in the fridge.
On the other hand, the unpasteurized sauerkraut has a much longer shelf-life after being opened. The raw sour cabbage can last for months as long as it is stored in the refrigerator and is kept completely submerged in the brine. After that, it will start deteriorating in taste, texture, and quality.
Remember that the unpasteurized type will quickly go bad if you don’t store it correctly with brine at cool temperatures.
Some Specifics about Unpasteurized Sauerkraut
Since this type of sour cabbage has live microorganisms and is continuously fermenting, you can expect to see some of these normal signs:
Bubbling and fizzing – this is absolutely normal and expected since the fermentation causes a build-up of CO2.
Bulging lid – once again, there is no need to worry if the lid is bulging because the CO2 gas build-up likely causes it.
Problems with unscrewing the jar’s lid – due to the gas build-up, the lid of the unpasteurized sauerkraut may become jammed. To open it, leave it out of the fridge for about 5 minutes, or try placing the lid’s edge under hot running water to help alleviate the pressure.
Each batch may taste slightly differently – this is normal since every batch of sauerkraut has its own unique microclimate and life.
So, How Can You Tell if the Sauerkraut Has Gone Bad?
While the above-mentioned signs are normal for unpasteurized sour cabbage, there are other signs that may be symptoms of spoilage of pasteurized and unpasteurized sauerkraut.
Here is what to look for if you want to determine whether the sauerkraut has gone bad:
A rotting or off smell is one of the most obvious signs that the product has gone bad. The normal smell of unpasteurized sauerkraut is fresh and fermented.
Changes at the surface – this can often happen if there are cabbage leaves left above the brine’s surface. Signs such as mold or a white film are not good, and to stay safe, we recommend that you throw out the entire batch if you see these.
A very long storage time – you should discard any pasteurized sauerkraut which has been opened and stored in the fridge for over two weeks. As for the live unpasteurized type, you can store it for as long as you want.
Please note that the unpasteurized sour cabbage will continue fermenting even in the refrigerator, so its leaves may become less crunchy, and its taste may change over time.
Summary of the Sauerkraut Shelf-Life
- Unpasteurized sauerkraut (unopened) lasts for 3 or more months after the sell-by date in the fridge
- Unpasteurized sauerkraut (opened) lasts for up to 6 months in the fridge
- Pasteurized sauerkraut (unopened) lasts for 3-6 months after the best-by date
- Pasteurized sauerkraut (opened) lasts for 5 to 7 days in the fridge
The unpasteurized type can last even longer than 4-6 months after being opened. But only if all of the cabbage is submerged in the brine and if you keep it in the refrigerator at all times.
But over time, as the fermentation continues, you may find that the sauerkraut has become way too sour for your taste.
The taste of the pasteurized type will not change for months after its best-by date if the can or jar has not been opened.
Remember always to read the instructions and the suggested storage requirements and time by the manufacturer.
Do You Need to Keep the Sauerkraut in the Refrigerator?
If the sauerkraut is raw, alive, and unpasteurized, it needs to be refrigerated at all times, even before it is opened. The cold temperatures will not stop the fermentation process but will slow it down.
When left at room temperature, the raw sauerkraut will ferment quickly and rapidly develop a sharp taste.
The pasteurized type is shelf-stable and will need to be kept in the fridge only after opening it.
The Importance of the Brine
To keep the sauerkraut at its best quality and taste and prevent spoilage, you should always make sure that all cabbage leaves are covered entirely with brine.
If left out of the brine, the cabbage leaves will quickly dry out, and you will notice mold or white specs and film appearing on the surface.
But what if there is not enough brine to submerge all of the sauerkraut?
Luckily, making your own brine is easy, so you can add some more to cover the cabbage completely.
How to Make Extra Brine
If you need more brine to preserve your sauerkraut properly, the good news is that all you need is some water and salt.
The standard concentration of salt in the brine used for sauerkraut is about 2%. But if you prefer it saltier, you can add some more salt to the brine.
To make standard sauerkraut brine, follow the ratio – 1 teaspoon of salt per 1 cup of water.
Stir the salt until it dissolves completely, and pour the brine in the jar or other container where you are storing the sauerkraut.
Ensure that the brine covers every leaf and part of the sour cabbage and close the container.
Return it to the fridge, and enjoy your delicious and healthy unpasteurized sauerkraut for as long as you like!
Related: Do Pickles Need to be Refrigerated?