Wednesday, May 9, 2012

A Fermentation Response From Sandor Katz

Wow!  There has been a lot of fermentation talk on the blogs lately!  In order to be fair to my readers, I would like to post a response by Sandor Katz, who wrote the Book Wild Fermentation.  He basically says that as long as you keep your ferments under the brine, you can continue to use mason jars for fermenting.

It's hard to keep things under the brine, but I just found these glass weights on ebay and plan to buy and try a few of these for some of my ferments.

I guess I am landing a bit in the middle.  I do have some gut issues that I want to heal, so I want to use the pickl-it and Harsch as much as I can.  But, as I heal, I am not opposed to using my mason jars with the glass weights on them.  I am curious to see how those work - my opinion may change again depending on how I like the masons with the weights.  One thing I will stand firm on is that weights are needed if you want to use mason jars for fermenting.  I have not been doing this, but after all the reading over the past few weeks, I see that they are absolutely necessary.

Also, I want to be clear that I do not discount the research that Kerry Ann has done.  I am sure that there are people with very serious gut issues that need to be healed with fermentations that are done in a strictly anaerobic environment.  This may not apply to most people, but just the same, I do think that it applies to some people.  You just have to figure out into which group you fall.  I am not totally sure where I fall yet, which is why I am trying all methods.

Here is the link to the weights:  CLICK HERE

Here is Sandor Katz's response:

"I hear that much controversy is brewing on the internet over vessels for fermenting vegetables, and the implications of whether or not they are totally anaerobic. I have made hundreds of batches of kraut in all sorts of vessels (most of them open crocks), and I have witnessed, consistently, that it doesn’t matter. Each vessel has advantages and disadvantages. No particular type of vessel is critical. People have been fermenting vegetables for millennia in crocks open and closed, in pits and trenches, in sealed and open vessels. It can be done many different ways. The only critical factor is that the vegetables be submerged under brine.

Whenever vegetables are submerged under brine, lactic acid bacteria (which are anaerobic) develop. Whether or not the vessel protects the surface of the ferment from atmospheric oxygen, the microbial development under the brine is anaerobic lactic acid bacteria. In the vocabulary of microbiology, lactic acid bacteria are “facultative” in that they that do not require oxygen, but are not inhibited by its presence; in contrast, certain other bacteria (for example Clostridium botulinum) are “obligate” anaerobes that require a perfectly anaerobic environment.

The only difference air exposure or lack thereof makes is whether aerobic organisms like yeasts and molds can develop on the surface. The barrel of kraut I have had fermenting in the cellar for six months now is good and sour, and I have been eating from it and sharing it widely for months. Each time I remove the cloth tied down over it, and the jugs of water weighing it down, and the two semi-circular oak boards that rest upon the surface, I skim off a moldy layer around the edges and down the middle, wherever the surface was exposed to air. I toss the moldy layer into the compost, and the kraut beneath it looks, smells, and tastes wonderful. Many people have reported how good it made them feel and not a single person has complained of any problems from it, ever. The brine protects the vegetables from the aerobic organisms that grow on the exposed surfaces. The ferment is a lactic acid ferment, even though the surface is aerobic. Surface growth should be scraped away because if it is allowed to grow it can diminish the acidity of the kraut and affect flavor and texture, but if you keep periodically scraping mold away, the ferment beneath is fine.

I have also fermented in Harsch crocks, Pickl-Its, Mason Jars, and many other types of vessels. Mason jars become highly pressurized if you fail to loosen them to release pressure. Even if they are not perfectly airtight, they permit little airflow. Many times I have witnessed carbon dioxide force its way through the airtight seal by contorting the tops to provide an escape for the pressure. The various air-locked designs that allow pressure to release while preventing air from entering the system are generally effective at preventing aerobic surface growth. Yet still I generally do not use them because I love to look at and smell and taste my krauts as they develop, and each time you open an air-locked vessel you defeat its purpose, allowing air in. The vessels are effective, but are not well-suited to my desire to taste at frequent intervals. Different vessels suit different needs and desires. No one type of vessel is essential for fermenting vegetables. I have had success using every type of vessel I could think of. As long as you can keep vegetables submerged, lactic acid bacteria will develop. The process is extremely versatile.

For more in-depth information on fermenting vegetables, fermentation vessels, and all realms of fermentation, check out my new book, hot off the presses, The Art of Fermentation. Keep fermenting…"


  1. Unfortunately Sandor is incorrect... because the vegetables are under brine it does NOT mean that it is anaerobic! Oxygen is dissolved in water and brine so fermentation will not be optimal until that Oxygen is consumed. In an open container the brine can continue to absorb Oxygen.

    1. Alan, Thanks so much for stopping by and taking the time to comment. I do agree with you after reading a lot of recent research and will be updating my thoughts and new culturing process in the coming weeks. Over the past month, I have just been using my harsch crock and pickl-it jars which allow for anaerobic fermentation. I'm new to the pickl-it jars and have been so please with the ferments I have done in them. I will be highly recommending their purchase to my readers as I think they are much easier to use than the Harsch Crock.