SC - period salt

[James F. Johnson]

Stefan li Rous wrote:

> My understanding is that in the Middle Ages, the Roman salt mines had
> reached the watertable and that all they produced was brine which was
> then evaporated to salt. The other source was salt produced by drying
> seawater. The latter apparently produced a lower quality salt, but it
> was preferred for such tasks as salting fish and meat since the larger
> crystals kept it from sealing the surface as easily as the other salt
> and thus not completely curing the interior of the fish/meat. The
> sea salt was sold at a lower cost.

[snip] 
> Since this was an Apicius recipe I'm not sure if the Roman salt mines
> were still producing salt vs. brine at that time.

My understanding of geology is that salt mines are in ancient sea
deposits, so the salt would still be 'sea' salt. The actually mineral
content would vary from area to area, and depend also on when the
deposit was formed. One benefit of mining salt rather than evaporating
it is that ancient salt is probably clear of any pollution or waste
runoff coming from a settled area nearby, unless groundwater is carrying
it in. 

The two current methods for mining salt is 'room and pillar' which is
much like it sounds, mining out 'rooms' in the deposit, leaving
'pillars' to hold up the ceiling. The other method is to drill into the
deposit, pump in water to dissolve the salt, and pump out the brine.
Much like the Romans were, except they didn't have to pump in the water
after digging down far enough.

Seumas

- -- 
Roi ne suis prince, ni duc, ni comte aussi; je suis sire de
Bruyerecourt.