Last summer many of you may remember my The Science Behind Sauerkraut Fermentation post. I also did an experiment with sauerkraut to see which jar(s) provided an acceptable environment for sauerkraut. I discovered there were several jar scenarios that would provide a safe, delicious sauerkraut. I published my results in Sauerkraut Survivor - Final Report.

Since then I’ve done a few more experiments.

I learned in doing Sauerkraut Survivor that the lactic acid bacteria (LABs) just barely got started around Day 3, and was puzzled why anyone would recommend that it was ready to eat on Day 3. After all, wasn’t the main draw to fermenting cabbage the richness of the probiotics?

I posted all the brine samples during the course of my series. Here is a photo of what the brine looked like under the microscope on Day 3 when the LABs have only started to grow. This is the first-stage bacteria, as you can see by their round shape. (click for larger photo)

Now compare that with this photo from Day 7 (below). You can see there are LABs that are long and thin - that is the second-stage bacteria. Just waiting until Day 7 improves the probiotic composition of your kraut! (click for larger photo)

Here is a brine sample from Day 28. Can you see the activity and density and maturity of the LABs? I know 4 weeks is a long time to wait, but it’s sooo worth it (click for larger photo)

Getting the Most Probiotic Kraut Possible

Since those results, I’ve always left my kraut 28 days before opening. It just makes sense. Plus, it tastes better! Much less salty, making it more palatable.

Not being able to leave well enough alone, I had to wonder: how long is too long? If 28 days/4 weeks is better than 3 days, would 8 weeks be better? How about 12 weeks?

And What About Refrigeration?

After my research writing The Science Behind Sauerkraut Fermentation I learned that LABs dislike the cold. Yet we are told to refrigerate the kraut - and just when they are starting to get probiotic!

This made no sense to me as fermentation is a method of preservation. Do you refrigerate your banana chips after dehydrating? Of course not!

Take a look at what Food Microbiology has to say about cold temps:

Chill storage changes both the nature of spoilage and the rate at which it occurs. There may be qualitative changes in spoilage characteristics, as low temps exert a selective effect preventing the growth of mesophiles [which are in sauerkraut] and leading to a microflora dominated by psychrotrophs; can also cause physical changes in micro-organisms that modify or exacerbate spoilage characteristics.

Then they give examples which include the fact it “changes metabolism due to the cold and causes chemical reactions that compromise microbial metabolism. Mesophiles [again, sauerkraut bacteria] can not grow at chill temps, but they are not all killed - the cold causes “cold shock” which causes death and injury in a proportion of the population.”

Do I Have to Refrigerate Once I Open the Jar?

Since I love the taste of room-temp kraut, I also wanted to know: could I continue to eat it, once open, leaving it on the counter until the jar was empty? Or does it need to be refrigerated once opened?

I knew that once the pH drops, it’s pretty near impossible to cause spoilage. I had to be sure…

The Big Test(s)

So I filled four 1-liter Fido jars with salted cabbage. One I dated to open in 4 weeks, one in 8 weeks, and two in 12 weeks. One of the “12 week” jars I left out the 3 recommended days before refrigerating for the remainder of the 12 weeks.

The brine sample for the 4-week kraut looked similar to the 28 day kraut above. It was delicious I continued to test this jar from time to time as we ate out of it (taking brine samples and looking at them under the ‘scope), and am happy to report no spoilage was found for the full 8 weeks I tested it. Hooray!

The 8-week kraut was also delicious, and check out the brine!!! WOW! (click for larger image)

Psst! - that rumor you may have heard that Fido jars allow for too much CO2 to be held in, thus causing LAB death? Debunked!

Here is the brine sample for the 12 week kraut that was on my counter. It had a sulphury smell to it, and the LABs have started to dwindle. I would not recommend fermenting your kraut 12 weeks on the counter.

Here is the brine sample for the 12 week kraut that was refrigerated. It, too, smelled sulphury. It is hard to say whether the LABs are dwindling like the counter kraut, or whether they never got to maturity at all. From all I’ve learned about temps, I am guessing they never made it to full maturity. I don’t recommend 12 week fridge kraut.

Conclusion

If you want to make kraut rich in probiotics, please do yourself (and your guts) a favor and resist the temptation to open your kraut for 4 weeks. And please leave it on the counter!

I found even after opening the jar, you can leave it on the counter until it has been consumed, preferably by around 8 weeks.

PLEASE NOTE:

I used a Fido jar for all these tests. The Fido jar does a wonderful job of keeping oxygen out, yet letting excess CO2 escape. The CO2 that is allowed to blanket the surface of the cabbage allows you to ferment without even using a weight to keep the cabbage under the brine.

I can not say how the results would be in another jar. In fact I do not recommend leaving your kraut out if oxygen can get to your cabbage, as it will spoil. My above recommendations are only for the Fido jar, as that is what I have experience with, and certainly not jars that failed my Sauerkraut Survivor test.

All are welcome to join the Fido Fermentation Group on Facebook, no matter which jar you choose to ferment in

Shared on: Fat Tuesday, Homestead Barn Hop, Thank Goodness its Monday, Family Table Tuesday, Sunday School, Fight Back Friday, Simple Lives Thursday

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Lea Harris founded Nourishing Treasures in 2006. A mom passionate about her family's health and well-being, Lea believes education is power. Encouraging others to take baby steps in the right direction of health for their families, Lea's goal is to raise awareness of what goes into our mouths and on our bodies, providing natural alternative information that promotes health and prevents disease by using traditional foods and nature's medicine. Lea is a Certified Health Coach graduate from Beyond Organic University, and a Certified Aromatherapist graduate from Aromahead Institute. "Like" Nourishing Treasures on Facebook, join the Nourishing Treasures Group on Facebook, follow @NourishTreasure on Twitter, and subscribe to our newsletter. You can also find me on Learning About Essential Oils forum, and Fido Fermentation Facebook group. Disclaimer: I use affiliate links wherever possible. So if you click on a link, and make a purchase, I might make a small commission, but it doesn't cost you any more.