How long in plastic fermentor before leeching/off-flavors?

I can't give you an exact time, but if you want the beer to sit for a long period of time, I would definitely recommend glass. It's also non-porous, so you can clean it and use it for non-sour beer.

 

It is not a good idea to use a plastic bucket for long term storage/aging since it is oxygen permeable. The issue will not be leeching but your beer will get oxidized.

You should use an oxygen impermeable vessel for long term aging (e.g., a Better Bottle or glass carboy).

Cheers!

 

I would get the Better Bottle instead of the bucket/lid in this case. Either that, or glass. You might be able to find used carboys on Craigslist in your area if cost is the issue.

 

As long as you want. I have an Oud Bruin in a 5 gallon right now that I brewed almost 1 year ago, no oxidation issues. My understanding is that Better Bottles are about the same as glass when it comes to permiability. Most of the oxygen exposure is from the rubber bung, dried out airlocks, and getting into the beer for sampling.

 

I can second this experience with my lambic inspired beer I have going. Zero oxidation or off flavors associated with bugs+oxygen. Nothing acetic, and this is with the airlock drying out twice during that span.

 

As was posted: for a very long time.

If you choose to purchase a Better Bottle for your aging I would suggest that you obtain a dry lock closure as well; that will yield the ultimate oxygen impermeability.

Cheers!

 

This is the one time I would specifically recommend a glass carboy.
First, oxygen permeability is virtually nil through the walls, and then comes to being careful about sealing the top to keep out air. Fortunately, CO2 is heavier than air mixture, and will blanket the beer if the airlock should go dry for a little while.
Also, glass you can sanitize out and reuse with regular beers; I wouldn't trust even a brand new plastic bucket or carboy from being contaminated. Those little buggers can hide out in tiny scratches and will sour anything else you put in it.
Most other times I would say that plastic better bottles have a lot of upsides to them and may be worth using, but like I said, a sour I would recommend glass.