Here’s all you need to know about storage, shelf life, and going bad of sauerkraut. In this article, you will learn how to tell if yours is bad and how long it will last.
There’s a lot of conflicting information about sauerkraut on the Internet. Some argue that it lasts forever, while several producers recommend storing theirs for only a week after opening.
It’s easy to get confused. This article is my attempt to straighten things out.
To start, let’s talk about the two types of sauerkraut available. Knowing the differences between the two will make everything else so much easier.
Unpasteurized vs. Pasteurized Sauerkraut
There are two kinds of sauerkraut available on the market: unpasteurized and pasteurized.
The main difference between the two is that the first one is raw and alive, with a whole lot of probiotics, while the second one is cooked, and most of the probiotics are dead.
And since the first one is alive and the fermentation process is ongoing, it needs to be refrigerated so that it doesn’t ferment too much and becomes too sour.
In pasteurized sauerkraut, the fermentation process has been stopped by applying heat, and because of that, there are no live bacteria. That means that as long as the can or jar is unopened, there’s no need for refrigeration.
That’s why you see some sauerkraut in the refrigerated section, while the rest sits on the shelves. The same logic applies to kombucha.
(Some products are in between. They aren’t fully pasteurized but don’t require refrigeration. Fortunately, most kraut out there is either one or the other.)
If you buy sauerkraut for its health benefits, choose the one that’s sold refrigerated.
Knowing that there are two types of sauerkraut: unpasteurized (sold refrigerated) and pasteurized (shelf-stable), let’s tackle spoilage, shelf life, and storage of both.
Does Sauerkraut Go Bad?
Pasteurized sauerkraut keeps only for a week or so after opening and easily goes bad. Unpasteurized sauerkraut, on the other hand, can keep for months after opening if you refrigerate it and keep it submerged in brine. It will gradually deteriorate in quality, however.
In other words, pasteurized sauerkraut can go bad quickly, while its unpasteurized counterpart doesn’t, assuming that you store the kraut properly.
Of course, if you don’t store your unpasteurized sauerkraut properly, it can dry out or even grow mold fairly quickly. That’s why it’s important to take good care of it.
(I cover storage in detail later in the article.)
Now, before we talk about signs of spoilage, let’s cover a couple of things you might find odd at first but are perfectly normal for unpasteurized sauerkraut.
Sometimes, instead of the word “pasteurized,” the phrase “hot-packed” is used. It’s essentially the same thing.
Things Unpasteurized Sauerkraut Does
As you already know, unpasteurized sauerkraut contains living organisms. That has several consequences.
Fizz and Bubbles
If your refrigerated sauerkraut is fizzy and bubbly after opening, that’s normal. The ongoing fermentation causes a buildup of CO2 gas, which doesn’t have anywhere to go because of the lid. Now that you removed the lid, the CO2 buildup can be released, causing bubbles.
That’s also why some brands put release valves on their packages.
(In case you were wondering, a similar thing happens to champagne.)
Same as above, the gas buildup can sometimes bulge the lid, and that’s normal. It’s not a common occurrence, but don’t panic if it happens to you.
Difficulty Unscrewing the Lid
The last effect of CO2 buildup in unpasteurized sauerkraut is that if it’s jarred, the lid might be difficult to get off.
Here are two things you can try to finally open that jar:
- Leave the jar at room temperature for 5 minutes. It might help relieve some of the pressure and allow you in.
- Run the lid edge under warm water for a few seconds. Same as above, we apply temperature change to help release the pressure.
Taste Differs Between Batches
Since refrigerated sauerkraut is a living thing, every batch is slightly different. So there’s no need to be alarmed if this container tastes a bit different than the last one. Unfortunately, that’s something that cannot be controlled.
Now that you know what’s okay for refrigerated kraut, let’s talk about signs of storage.
If your fermented cabbage is pasteurized and shows either of these signs, it’s almost certainly bad. You might want to check with the FAQ section of the brand’s website for confirmation.
How to Tell if Sauerkraut Is Bad?
Signs of spoiled sauerkraut include:
- Off smell. If it smells funny, off, or like it’s rotting, it’s obvious that sauerkraut has gone bad. Sauerkraut should smell fermenty and fresh.
- Changes on the surface. If the brine doesn’t cover the leaves, a couple of things could happen. They might dry out a bit, which isn’t a problem. But if they’re uncovered for more than a couple of days, either white film (photo below) or mold shows up. If your kraut is unpasteurized, you could, in theory, eat whatever is under the brine, but I think discarding the fermented cabbage, in this case, is the way to go. Better safe than sorry.
- Too long storage time. If your kraut is pasteurized and open for more than, say, two weeks, it’s time for it to go. It doesn’t go bad quickly because it’s usually brined with vinegar (which helps prevent bacteria from multiplying), but it doesn’t last that long either. As for raw sauerkraut, go with whatever you’re comfortable with time-wise (more on that later).
Finally, if everything seems to be fine, tasting the sauerkraut is the last step of the process.
Now, if it’s the unpasteurized variety, the thing is still alive and the fermentation is ongoing. That means the taste might change over time, and the cabbage might lose some of its crunch if it sits in the fridge for months. Be prepared for that.
Otherwise, go with your gut. If it still tastes good and the storage time is reasonable, go for it.
How Long Does Sauerkraut Last?
|Sauerkraut (unpasteurized, unopened)||Sell-by + 3+ months|
|Sauerkraut (unpasteurized, open)||4-6+ months|
|Sauerkraut (pasteurized, unopened)||Best-by + 3-6 months|
|Sauerkraut (pasteurized, open)||5 – 7 days|
Unpasteurized sauerkraut can keep for 4 to 6 months after opening the container, or even longer. The quality will gradually degrade, but as long as the cabbage is covered in brine, it will stay safe to eat.
Pasteurized sauerkraut, on the other hand, usually keeps for about 7 to 10 days of opening.
As you can tell, the difference between the two is hugely in favor of the unpasteurized one.
Of course, the suggested storage time depends on the brand. Often, brands recommend going with the best-by date printed on the label or maybe adding a couple of extra months past it, no matter when you open the container.
That’s because the fermentation process is ongoing, and while the cabbage will stay safe for quite some time, it will retain peak flavor for only so long. Like kimchi or unpasteurized pickles (do pickles go bad?), its taste will deepen over time, and at some point, it might become too sour for your taste.
As for pasteurized sauerkraut, it keeps for months past its date, as long as it’s unopened. But once you open the container, you only get a week and change to get the best results.
As I mentioned, pasteurized sauerkraut usually includes vinegar in brine. The vinegar helps the fermented cabbage last more than the usual 4 to 5 days of opening for canned foods, but the storage time is still quite limited.
Read the label. If your sauerkraut is pasteurized and the label says you can safely store it for longer than the mentioned period, follow that recommendation. Same thing if it says you should use it or discard it within 4 to 5 days.
Now that you know how long it’s good for after opening, it’s time to talk about how to store sauerkraut.
Does Sauerkraut Need to Be Refrigerated?
Unpasteurized (raw) sauerkraut requires refrigeration at all times, while its pasteurized cousin only after opening the container or jar. Of course, keeping unopened pasteurized sauerkraut in the fridge is also an option.
As I already mentioned, raw (unpasteurized) sauerkraut is still fermenting, and to slow down that process, you need to refrigerate it.
If you leave it on the counter, the process will speed up. And while it will not necessarily make the cabbage go bad, its taste will get much sharper in a matter of days.
(Which essentially makes the fermented cabbage useless or bad.)
Pasteurized sauerkraut isn’t fermenting, so there’s no need for refrigeration. Instead, you can treat it the same way you treat all other canned vegetables. That means you transfer it to the fridge only after you open the jar or can.
Having that out of the way, let’s talk about a crucial storage practice – keeping the cabbage under the brine.
Keep Cabbage Submerged in Brine
Once you open your sauerkraut, make sure everything is nice and submerged in brine before you return the leftovers to the fridge. And each time you scoop some, remember to push down the rest of the cabbage so that it stays covered.
Otherwise, the cabbage that’s in the air will start to dry out, and within a couple of days, there will be white specs (and eventually white film) or mold on the surface. I already talked about it in the section on spoilage.
Now, what if there’s too little brine in the container to nicely cover all the cabbage?
Fortunately, there’s an easy solution to that issue – you can make extra brine. Here’s how.
Making Extra Brine
Making your own brine is easy. All you need is water and salt.
We’re going to make a 2% (approximately) brine, which is pretty standard for making sauerkraut. If you like yours on the saltier side, you can add more salt.
To make the brine, dissolve 1 teaspoon of salt in 1 cup of water. If you need more brine, double or triple the ingredients.
Once you have the solution ready, pour into the sauerkraut container as much as you need to cover the cabbage. That’s it.
Here’s how that looks like:
Once your cabbage is nice and covered, you can return it to the fridge where it stays safe for months.