Gypsum in both batches....I had read somewhere that this was a good source of calcium for the yeast in sugar washes. Of course it is also a source of sulfur.
i think gypsum is just a source of calcium and magniesum? no sulpfur?
and i think it only is usful when used in a mash to lower ph? it reacts with some other stuff, or something along those line...other wise it's basic?