My aunt Birgitta, who has over 40 years’ experience of making traditional fermented foods, would say that salt is vital for the fermentation process and without it the vegetables might rot instead of ferment. Other experts, including Mr Sandor Ellix Katz, say that salt is not necessary for fermentation. However, the likelihood of a successful ferment is much higher if you do include salt.
Some people have been told by their doctor to reduce their salt intake, for example if they have high blood pressure or severe kidney problems. You should in these cases choose to omit the salt and instead use something like seaweed that has a natural salty taste as well as minerals. If you have high blood pressure or kidney problems you must consult your cardiologist or nephrologist for more advice, if you are unsure about using salt in your ferments.