If you can avoid italicizing altogether, do it.
Italicizing makes the reader stop to think about how the sentence should be "interpreted." That pause is distracting. (I find myself stopping to reinterpret several times when trying to see what the person saying your first sentence is really doing...)
Instead use the context, actions (especially), and previous events to give the reader a hint about how it should be read.
When you put in the italics, do you have an image of what the person is doing? What their facial expressions might be? How they interact with their surroundings? Especially "this" and "that old thing"...
Use that instead of the italics. Act out the dialog! Show me in text what the people do when they say what they say.
This is how I would have done it without the italics (and I leave open the question of if this is too much emphasis...):
George took a drink from the glass. He sighed. "This is," he said, taking another drink from the glass, nodding and humming in appreciation, "so much better than this..." He took the other glass, holding it up for scrutiny, then frowned and poured it out in the sink. "...old thing. Bleh!"
Don't be too afraid to let the readers have their own interpretation. They will anyway, and sometimes it will be different from what you were intending, sometimes a lot different.
It doesn't have to mean you've failed, just that people are different and the "guy" one reader made up in their head (based on their experiences) didn't do it the way you saw him doing it. That's how reading a text works. The reader makes up people, places, etc, and they won't always be what the writer thought they would be.
As a writer, your job is to write a text that will allow your readers' minds to create these worlds without intruding on them or destroying them. Your job is not to mind-control them into seeing and feeling exactly what you see and feel... Which is good, since it's doomed to fail...