How to Make It
Using a sharp knife, cut kernels from cobs to equal 8 cups; set kernels aside. Bring corn cobs and 18 cups water to a boil in a large pot over high; reduce heat to medium, and simmer until stock has a light and sweet corn flavor, about 1 hour and 30 minutes. Pour corn stock through a fine wire-mesh strainer into a large bowl; discard solids.
Bring 4 cups corn kernels and 2 1/2 cups corn stock to a boil in a medium saucepan over high. Reduce heat to medium, and simmer until kernels are crisp- tender, about 25 minutes. Transfer half of the corn mixture to a high-speed blender. Secure lid on blender, and remove center piece to allow steam to escape. Place a clean towel over opening. Process on low speed, gradually increasing speed, until smooth, about 30 seconds. Transfer pureed mixture to saucepan with remaining corn mixture; scrape in vanilla bean seeds, and discard pod. Stir in vanilla bean seeds until combined. Set creamed corn aside.
Add 1/4 cup corn stock and remaining 4 cups corn kernels to blender; process on high until smooth, about 45 seconds. Press mixture through a fine wire-mesh strainer into a medium skillet; discard solids. Heat corn puree over medium, and cook, whisking constantly, until slightly thickened, 5 to 6 minutes. Remove from heat, and let cool until thickened to the consistency of pudding, about 20 minutes. Spoon into a small bowl; place plastic wrap directly on surface. Refrigerate until ready to use.
While corn pudding chills, bring 5 cups corn stock to a boil in a medium saucepan over high. Gradually add polenta and salt, and cook, whisking constantly, 2 minutes. Reduce heat to low, and position the saucepan over the burner so the heat source only partially touches the bottom of the pan. Cook, whisking often, until grains are tender, about 15 minutes. Place saucepan directly over heat, and whisk in creamed corn. Cook, whisking often, until thickened, about 5 minutes. Stir in 1 cup chilled corn pudding (you may have some left over) until blended. Immediately remove creamed corn grits from heat, and serve.