Don't use regular or kosher salt for fermentation

My friend was inspired by my results and tried to make sauerkraut. Unfortunately, he used kosher salt. It ended up smelling weird and bad. I have used sea salt and canning/pickling salt successfully. I think my wife said that kosher or regular salt needed to be boiled to diffuse itself through the mixture. Sea salt will add micronutrients to the fermentation. Salt is important to delay or inhibit most bacterial growth until the lactic acids can take over. If you don't put any salt, you risk the problem that my friend had: random unhealthy bacteria will take it over instead of the desired lactic acid bacterias. You will probably get sick if you let random bacteria take it over.
John S
PDX OR

I've used kosher salt to ferment hundreds of times without any problem.
It does not need to be boiled in order to form a brine solution.

Some people prefer the sea salt because it does not typically have the anti-caking additives that kosher salt has.
But none of that will effect your ferment.

Regular table salt has iodine added to it, and that may theoretically effect the growth of your bacteria, but I have not ever noticed that in a quantifiable way in real life.

Whatever the cause of your friend's issues, you can safely assume it was not the type of salt.

Did you smell it yourself?
I have found a lot of people are very nervous about their first ferments and prematurely assume something bad happened.

Did he buy whole cabbage and shred it or buy the pre-shreded, bagged variety?

Thanks Mark,
That's great clarifying information. My wife may have misunderstood something about the salt. My friend came to me to talk about the sauerkraut smelling off, so I smelled and tasted it. I have bought and made sauerkraut many times and it didn't smell right. I assume it was due to the wrong bacteria developing in there. It didn't smell or taste like regular lactic acid sauerkraut. He shredded the vegetables himself. The only other thing I can think about is that it wasn't really covered very well. I use the traditional plate and rock method to make sure everything is weighted down under water. He didn't have anything covering the water, but the food was almost always covered by water. The lactic acid never seemed to get going, not even after 3 weeks.
I'm also wondering if he failed to make sure that there was enough salt or that it was thoroughly mixed throughout the brine solution.
JohN S
PDX OR

I have read that Kosher salt isn't ideal for canning and fermenting due to the flakes not dissolving as quickly as canning salt. That being said, all it takes is a short trip through a food processor to turn Kosher salt into the finer gained canning salt.

If the cabbage was store bought it may not have had enough lactic bacteria to get the culture started.

"Kosher" salt refers to the form that the salt is in (fairly large, flat, somewhat sharp grains) vs table salt (tiny perfect cubes) or rock salt (big, icemelting chunks.) Kosher salt is used to make other foods Kosher by drawing out water and blood, I don't think the Torah/Bible says much about how salt must be made, but I am certainly not an expert on that.

I like to use sea salt for my ferments, because of the micronutrients, both for myself and for the bacteria. It's usually been refined at least a little bit, and the most recent box I got is actually Kosher sea salt.

Another thing he could have used tap water and that won't work.

You shouldn't need to add any water to sauerkraut. Chop the cabbage and layer it in the container, adding salt every 1/2 inch or so. Press each layer down hard with your knuckles. The salt should extract enough water from the cabbage. If not, your cabbage is too old...

I don't shred my vegetables in the sauerkraut, I chop them. Even though I chop them right away, I have never had them come close to not having enough water to cover them. It is crucially important for the vegetables to be completely covered with water for them to become sauerkraut. Cabbage is not the only vegetable I put in my sauerkraut.
John S
PDX OR

Water content in vegetables will fluctuate based on a few different factors. If you kneed/crush the veggies with your hands in a large bowl prior to placing them in the fermentation vessel it helps to get the process started. Save the liquid and add it into your jar/pot/etc with the veggies. Another option is to increase the weight used to keep your food submerged. When mixing vegetables it can be necessary to add a salt brine mixture to compensate for the added volume.

As a salt replacement option I have used sea vegetables (kelp, wakame, dulse, nori, etc..) to create an infused salt/mineral brine that when added to fermentation batches creates a unique flavour and is highly nutritious. I will happily share my process if anyone is interested.

I would be interested to hear that JW. I have used sea water directly when I went crabbing, but I've never used the vegetables themselves as the brining method. I usually crush the vegetables with my hands somewhat while they're already in the brine. I am trying to use as little salt as needed, because some studies have shown that high radish kim chi consumption is associated with higher gastric cancer rates. Radish is a very high nitrate vegetable. My guess is that lots of chile and lots of salt can aggravate the stomach. Radish eaten with some kind of fat can lead the nitrates to convert into nitrites, which are carcinogens. When people make kimchi, they usually soften the vegetables with a very strong salt brine first, then add salt to the kimchi later. Non-radish kimchi was associated with lower rates of gastric cancer in the studies. I am trying to guess about the best ways to not annoy my stomach and increase gastric cancer rates. Sometimes I reuse the brine and just add rain water, as it is already filled with lactic acid and I don't need to add more salt. I do think that some salt is important at the beginning on a new sauerkraut to avoid bacterial infection until the lactic acid takes over.
John S
PDX OR

John,
I had not heard that about the radish/nitrate connection. Thank you. I will look into it. I can't speak to the radish subject but I have plenty to say about the process of food fermentation.

It is my understanding that the salt used in fermentation has multiple purposes. It acts as a preservative in the initial stages and, due to Osmosis, allows water rich vegetables and fruit to create their own brine. Your plan to keep the salt low may be the source of your drier than expected conditions. Kim chi is not traditionally made using the same methods as sauerkraut. The european cabbage fermentations conduct their process in an anaerobic environment, like a pickle brine. I suspect the kim chi process of soaking in salt (or using a salt rub) and rinsing works to destroy pathogens and break down some of the cell membranes in the vegetables. The spicy pepper mixture is a second tier preservative to guard against invasives. Are you fermenting in a more Korean style or european?

I have reused brine to speed the process up by inoculation from time to time. My personal preference is to not transfer brine more than once. I like a fresher flavour and appearance. The fermentation process needs Osmosis to draw the liquid out the vegetables. I have found that soaking vegetables in a cultured brine without the first part doesn't yield the same results.

There is no harm in using less salt. If you are using cabbage in a brine ferment but there isn't enough liquid it is easy to add more salted water at any point. The level of preservation is proportional to salinity of the mixture. A low salt brine ferment may be more susceptible to negative bacteria and molds. Environmental conditions also effect this so it is difficult to say how little is too little. Keep an eye on it. Putting your vessel someplace cold will help preserve the contents at the expense of speed. Other materials like hot peppers (as mentioned above) or garlic will also help increase the preservative nature. Salt also aids in breaking down the vegetables. Crush them more beforehand if you would like a low salt brine.

Sea vegetables are good sources of non processed salt and minerals. Put them in a jar and add enough water to cover them (more water if dry seaweed). Leave it over night, or a day in the fridge. Dry seaweed will double or triple in size so keep an eye on it. Use this salt/mineral rich water on veggies instead of dry salt. This process is very trial and error and to taste. Chop up the sea veggies and add them to your fermentations for a good textural contrast and flavour in the final product.

Thanks for reading my long winded response. I am new to the forums and not yet acclimated to the forum culture.

We've been using common iodized table salt to make hundreds of pounds of kimchee and other fermented vegetables here for the past 5 years and have never had a failed ferment as long as it was mostly cabbage.

Iodized table salt is not actually a problem for fermenting.

Many people have reported problems with regular or kosher salt. In trying to figure out why it works sometimes and sometimes not, I think it is wiser of us to say that sometimes it is not a problem, and try to figure out why and why not. It could be seen as irresponsible to make a blanket declaration that it's always ok when we have several reported incidences of problems with it. For example, it might be ok usually if the fermentation is made overwhelmingly out of cabbage, which mine is not.
I think your experience of not having problems with regular iodized salt is an important contribution to the array of experiences we are sharing.
John S
PDX OR

Iodized salt is not usually used in either lacto-fermenting, cheesemaking or water bath canning/pickling, but that doesn't mean its use will always spell failure. In fermenting and cheesemaking, the iodine may inhibit the action of the lactic acid and slow or stop fermentation. Iodine levels vary depending on the brand so you may still get fermentation with table salt, or you may not. I, for instance, have used table salt to make cheese, and it worked, but I wouldn't do it again. My time, and my goats' milk, is far to valuable to potentially ruin the final product by using table salt. When pickling with vinegar and a water bath canner, table salt isn't used because it makes the solution cloudy in the jar. Since I don't care so much about cloudy, I still use table salt to pickle if it's all I have for whatever reason.

Luckily, sea salt is cheap (at least where I'm from!) and readily available!

On the subject of the original post and the smelly sauerkraut, it would definitely be the lack of a weight that would turn the kraut bad. If even a wee bit of the vegetable matter floats up and comes in contact with the air is grows all types of unwanted bacteria and starts to smell very awful indeed.

Just to add to the array of experiences -- I've used all kinds of different salt (including common table salt when nothing better was around) and water of many provenances (including city-chlorinated tap when I was out of spring/well water) and I have never had a ferment fail to start under any of those circumstances. I'm sloppy and do open-top fermenting so I've had lots of jars go moldy due to my own error, but no kind of failure that ever seemed to be related to salt or water. My conclusion is that the anti-microbial effects of the iodine and chlorine simply can't compete with the LAB we rely on to ferment our veggies.

I also have not had a problem using regular cheap grocery store salt.  I used that because I didn't know better.

I recently opened a carrot ferment that I made around 2018.

I keep my ferments in the fridge so maybe that might make a difference.