After the nastygrams that arrived in my e-mail inbox this week and some of the comments I’ve had to delete off the blog from Part One of this series and my fermented french fry recipe, I would like to clear something up.
I do not hate mason jars. In fact, I love them. I live with a few hundred, in fact. They’re quite nice to me and I’m quite nice to them. I stuff them full of some of my favorite products and send them to a nice day at the spa in some very hot water on a regular basis. They love me for it.
I just don’t use them for ferments.
Are Mason Jars Traditional?
No traditional society fermented in glass as far as I can tell. But that doesn’t mean I think that you should go to using sheep’s stomachs to ferment your milk. It does mean that I believe you should make all efforts to duplicate the same environment that native people use to ferment. And the mason jar is not that.
Traditional societies overwhelming fermented in anaerobic conditions- we’ll go over this in detail in later posts. Anaerobic means that oxygen isn’t being let into the environment while fermentation is taking place. Aerobic means that oxygen is continuously present- there is a fresh supply available and it gets renewed at least periodically. We’ll revisit this in a minute.
The Pickl-It and the mason jar aren’t comperable. The Pickl-It is in a different league. The only reason the two get compared to each other is because they’re both made of glass. The Pickl-It’s direct competition is the Harsch crock, not the mason jar.
Really, it’s a shame that the mason jar got so entrenched in the fermenting world because it’s really not what is needed to produce true, complete ferments loaded with gut healing lactic acid bacteria (LABs). They produce two different products out of the same vegetables, each with different bacterial profiles/amounts and each with different species. Then you throw whey into the mix and you’ve got a bigger issue, but we’ll discuss whey on another Friday.
The Pickl-It is on par with a Harsch crock as both are anaerobic, not a mason jar and definitely not an open bowl as those are areobic. According to the makers of the mason jar, they are NOT air-tight unless they are canned with heat in a water bath or pressure canner and there is evidence of a solid seal between the sealing compound on the lid and the glass rim of the jar. The sealing compound just isn’t thick enough and the ring strong enough to create a reliable, completely hermetic (airtight) seal without the use of heat. And the ability of a mason jar to hold a vacuum seal isn’t evidence of their ability to be airtight during fermentation, either.
Have you noticed how the hermetic jars such as the Pickl-It and the Fido, and even the Grolsch bottles for making water kefir sodas (or homemade beers, but we’ll get to that in a minute) have a very thick rubber ring with a locking lid? That’s because the thickness of rubber combined with a lid held on by tension is necessary to create a hermetic seal. The rings of the mason jars, even when being used with an airlock attached to a lid, just aren’t airtight.
Seriously- ask a professional beer-maker if your mason jar is acceptable for fermentation or storage of beer and they’ll roll their eyes and laugh at you.
I love my mason jars, but they are NOT airtight and they will not produce the anaerobic environment that the lactic acid bacteria need to be able to out-compete the oxygen-loving bactera.
But My Veggies Stay Under the Liquid
Yes, that is good. They need to stay under the liquid so the bacteria can access them to eat the sugars and starches they consume in order to make lots of LAB babies. But being under the liquid doesn’t keep them anaerobic. When oxygen comes across a liquid, it diffuses into the liquid, providing an endless supply oxygen to the liquid in which you’re trying to ferment. Any basic science textbook will explain this process. That means the LABs, can be out-competed by the oxygen-loving bacteria and the LABs can die off.
Have you ever had a refrigerated batch of sauerkraut in a mason jar turn limp and gray or go mushy even though you haven’t added whey? That’s caused by the jar not being airtight. LABs stabilize the color and cause the long-lasting crunch, even if the jar is a year old. Non-whey ferments that go soggy, limp or nasty are due to the presence of oxygen-loving bacteria that proliferate due to… oxygen.
Have you ever had a batch mold? Mold is aerobic– it only grows when supplied with oxygen. Even that ‘harmess’ white mold (that isn’t) they tell you to scrape off. Notice mold grows on the surface- where it can get the most oxygen.
Then What’s Happening In My Mason Jar?
So if it isn’t fermentation, what is it? If any oxygen is present, what is happening is called cellular respiration. You see, LAB production doesn’t begin immediately when you lock the lid down on a Pickl-It. First, cellular respiration must use up the last of the oxygen before the LABs can begin reproducing in droves in the oxygenless environment because their competition has been eliminated. The road to a complete ferment takes the same steps every time, it doesn’t matter what you’re fermenting. It takes the bacteria 2 or 3 days to use up the air in the top of the jar before it can go anaerobic, and I bet you’ve burped your jars at least once by then or fiddled with it, removing the lid.
Every time you re-supply the areobic bacteria with oxygen and the process starts all over again. If you’re using an inferior air-lock, it’s basically the equivalent of a slow leak, continually providing small amounts of oxygen. Either way, the LABs don’t stand a fighting chance with the continual re-supply of oxygen.
It takes 3-6 days for the concentration of LABs in an anaerobic fermentation vessel like the Pickl-It to reach 1% and that is only the first of several stages of fermentation. So even if you are fermenting in a mason jar and taking the risk of not burping it, if you stash it in the fridge after 3 days, it’s only partially fermented. But you likely have a mess on your hands because the jar has either leaked all over the place since the threads aren’t airtight (if they aren’t water-tight, they aren’t air-tight, either) or the jar has exploded by now.
So you see that the mason jar and the Pickl-It aren’t competitors, even though they’re both made of glass. The Pickl-It functions like the Harsch crock.
Want to read more about fermentation, including articles with references and more information on vessel types? See our Related Posts for all of the articles in this series.