I too have noticed the recent introduction of imported bufala in a local supermarket, but I have hesitated to try put off not only by outrageous price, but mozzarella simply does not age well, and there is no way to ascertain how old it is. Were the purveyor a specialist cheese shop with good turnover of product regularly airfreighted, I wouldn't rue the premium for the occasional treat. There are a few US producers, Bubalus Bubalis in California comes to mind - www.realmozzarella.com. Still, whatever possibly could be comparable to impeccably fresh mozzarella collected from an artisanal producer in the Campania, San Marzanos just plucked from the vine to craft the essential pizza.
I have found that you can actually get a pretty good idea of how old buffalo mozzarella is before you open the package. If it is one of the brands packaged in the plastic pouch you even have two ways to determine the freshness without opening. One way to get an idea is to look at how clear the water is. If it is really fresh you will not see any little floaty bits of white cheese, and it will be crystal clear. If you start to see bits of cheese shredding off of the main ball it has been around for a while. If the liquid is just a little cloudy, but there are no shreds or bits of cheese coming off of the ball the cheese is still good. The other way you can tell is by feel. A fresh cheese will have a good amount of springback when you smoosh it a little. It will fell somewhat firm, almost meaty, and return to form after a soft pinch. If it is too old it will just stay compressed and you will see it start to break apart and disintegrate.
I have found that this stuff can actually keep a lot longer than I was originally led to believe. I have picked up really fresh bags and used them up to two weeks later with great success.
Is there anybody out there that knows which way of storage is better.
A, to just leave the fresh cheese in water until a few hours before use even if it is for a week or more, or
B, to drain it right away after purchase, slice it, salt it, then store?
I know that salt is a preservative, and I usually pre salt my cheese anyhow before putting on the pies. This method of salting before storing has seemed to make the cheese last for a long time with no noticeable change in flavor or texture.
I have even heard someone recommend changing the water to keep the cheese fresh for longer, but I have not tried this.