I know that elements of this have been covered before, but I would like some advice.
I picked up a couple of 25 liter containers, that would potentially be useful as fermenters. They are HDPE, with a 2 in the triamgle on the bottom. They are solid black.
Would these be useable, or should I avoid?
http://www.ecologycenter.org/iptf/plastic_types/HDPESCIENCE.html
Do not eat if you are a mouse. :-p
As long as they don’t get hot (TFA says they start warping at around 60 deg C/140 deg F) you should be ok. The only concern I might have would be any residual moulding from when the containers were cast - might make cleaning difficult and could be a harbor for bacteria.
I would follow the advice in this. Not all HDPE containers are food grade, and the black color might make me say no.
If there is a label on the bottom that says NSF, it would be food grade.