Why? How much? What kind? of salt do I need for fermentation?
Salt seems to cause a lot of consternation for the new fermentista so I thought I would add a salt post to troubleshooting fermentation.
Salt doesn't preserve
First the salt doesn’t preserve the veggies the acidification of the process does so if you are worried about "killing yourself" more salt doesn't make it safer. (Keeping it under the brine does.) What the salt does is give the good bacteria (#lactobacillus) the upper hand to get started and once these guys get going they quickly overwhelm any "bad" bacteria with their acidic output.
Crispy and Tasty
Salt also hardens the pectins (that’s your crisp) and slows down the fermentation a bit, which can be important in hot climates or if you are storing without refrigeration. Salt also makes your ferment taste better, remember salt is a flavor enhancer. Of course too much salt and it is no longer tasty. Choose a mineralized salt you love, taste your ferment for saltiness—should be salty like a chip not briny like a mouthful of seawater. Most importantly — It should be tasty!
What kind of salt?
What kind of salt is personal preference though I don’t use processed industrialized salts, like pickling salt, etc.
How much salt?
This is where things get confusing. The truth is I never measure my own ferments, for me it feel but I do measure and now even weigh the veggies and salt when I am developing a recipe for others. I try to stick to a 1.5 % ratio by vegetable weight. This is enough to do what salt needs to do. Many recipes go as high as 5% and for me that is way too salty and doesn’t make the ferment any safer. So there is a lot of variability!
If you read older recipes you will see things like "packed in salt" or amounts that are crazy high. This is because they had to keep their ferment working a little slower because it stayed in a cool spot like a basement all winter and never was slowed down by a refrigerator. They also did not have as much salt in their regular diet as we do now so it wasn't a problem in many cases the ferment contained the salt that was added to an otherwise bland, starch-based meal.
I have over-salted, does the salt go away?
Somewhere the myth that the salt in a ferment goes away is out there alive and well. Sorry to report it has no where to go--too much salt continues to be too much salt. (In fact if anything a long ferment could evaporate slightly thereby concentrating the salt.)