Some tahini tastes very salty, other tahini does not. Why?
Just toured 17 tahini factories in Palestine. The traditional process soaks the sesame seeds in salt water, first to soften the hull for de-hulling, again to separate the hulls from the seeds, and finally to obtain the desired flavor. The seeds are rinsed in fresh water prior to drying and roasting.
Alternate de-hulling processes avoid the initial salt water soak, but retain the salt water soak after de-hulling and prior to rinsing and roasting to obtain the desired flavor.