Being a process, i feel like Chaptalization is the better word. Other than that though im not sure if there are companies that offer that service, I would think most wine makers do their own chaptalization.. if you can find companies that do, it could be worth some to them, it's just such a non common word to most people I feel it hurts the value to much. Id say maybe $xx unless you find that end user then, $xxx..
Just my opinion though.
Edit.. looked around and didn't see anyone offering that as a service, however I think if you developed it as an informative with different formulas and info it may get some ad traffic