I suspect it's not much more than DME when it comes to beer. Every online store I went to that had a yeast starter had DME and Yeast nutrient. I went to Carlson's site and couldn't find it but I betcha that's what it is.
Cry 'Havoc,' and let slip the dogs of war;
That this foul deed shall smell above the earth
With carrion men, groaning for burial.
Prim 1: Ogre's House Red Ale
Prim 2: Apfelwein