Joe I am going to post something Tom Shared last week with another Group..
I would not use these for any aging. Water bottles will let O2 in through the walls and will oxidize.
If it was OK there would be no market for better bottles.
But take a look first at the underside of the bottle at the symbol...
Here's some of the other codes....and some info.
1. PET or PETE – Light gauge containers such as store bought pop bottles should be a one time use only. Heavier gauge containers show no evidence of leaching chemicals.
2. HDPE – not known to leach unwanted chemicals.
3. PVC or V – Bad – Strong evidence to show the leaching of DEHA, a known human carcinogen.
4. LDPE – not known to leach unwanted chemicals although not as widely recycled as #1 or #2.
5. PP – not known to leach unwanted chemicals although not as widely recycled as #1 or #2.
6. PS - suspected to possibly leach harmful carcinogens
7. Assorted but usually polycarbonate – Bad – may contain leaching BPA.
Basically though 1 is the best 2 is ok....the other ones besides leaching problems are also the most succesible to oxygen permeability.
And as Steve tells it "Wine oxidizes and goes bad. I have never heard of water oxidizing and going bad. Thus a container may be fine for water but not for wine."
With this all said, I personally would not use a water bottle except for an emergency, knowing I could get it in glass within a day or so. Others will tell you they have used them succesfully so its totally up to you and the risk you're willing to take.