P.E.T bottles - Life span

drink quickly and enjoy

For ordinary recycled soda bottles the six month rule is best - but you got yours at a brew shop? Ask the proprietor. No brown soda bottles that I'm aware of, so they might be different in other ways.

Pet soda bottles will withstand very high pressure so you can over carbonate them and help keep the fizz longer - at some point the bottoms get round and they flop to their sides . . .

Nahh... the CO2 doesn't leave the bottle (unless the lid has a poor seal). I've had beer in PET for years in the past, with still excellent carbonation. HOWEVER, leaving it in PET for more than 6 months will almost certainly result in oxidation - ie., yucky taste. I did have some 2 Liter bottles that were drinkable (but not good) after 2 years. Smaller bottles oxidize much faster - the 6 month rule is probably right.