Read a post a few nights ago about freezing wine and pouring off the alcohol. The legality of this was also discussed. Let's say a friend of mine at an undisclosed location tried this. He froze bad wine to a heavy slush and drained off that which didn't freeze. He checked the SG against the OG of the wine when he made it. The SG had gone up over the final gravity reading of the wine. It makes sense, removing the water would make the liquid more dense.
Now for the question : How do you measure the alcohol level for something done in this way ? Could you take the FG of the wine and compare it to the SG of the strained-off liquid and do the math in reverse?