I have not been able to figure out what is wrong with sulfured molasses.
I have been reading up on molasses lately trying to figure out why we cannot use the sulfured type. The sulfured molasses is what many, many farmers use because it is cheaper. They use it as part of their feeding program for their livestock. Sulfured molasses does contain sulfur which many, if not all, plants need for growing. The sulfur is added to the raw sugar beets or sugar cane to speed up the process of making molasses. Without the use of sulfur the production of molasses would take a lot longer because of the extra time spent boiling the syrup. Time is money, probably the primary reason that "Unsulphured" molasses costs so much more.
Unsulphured molasses does taste better to most humans which is why it is used to make Molasses Cookies or Gingerbread Cookies and is added to some types of bread dough. It is added to sugar to make "brown sugar" which is used in some recipes for cookies, cakes, bread and some glazes. I did a personal taste test and the sulfured molasses certainly is no wheres near as tasty as the unsulfured molasses that we buy in the baking section of the supermarket.
About 6 months ago I spent an afternoon reading web articles on the use of molasses as it applied to the organic growing of fruits, vegetables and flowers and. I did not find any article that claimed it was bad, when gardening or farming, to use a molasses that was made with the addition of sulfur to speed up the manufacturing process.
My plants like an occasional brew with the inexpensive molasses mixed with the water. I have put this less costly molasses into some of my brews which also have worm castings just to speed up the growth of bacteria and the plants like that too.
Enjoy the day...