OVHA Chat

I left Some spent grain in my mash tun and it soured.Smelled sorta' like vinager;I soaked in 'PBW' and thought it was gone.Today,I opened it up and a faint whiff of it still remains,although it's barely noticeable after a minute or two.I'm wondering if this could impart any odor into my wort on the next mash.Surely I'm not the only one who ever did that.Any thoughts on this problem?

I'd try bleach water . That seems to work for getting stains and odor out of my mash tun/cooler. Just make sure that you give it a good rinse before use. Another good product is Star San. It is an excellent sanitizer and doesn't need to be rinsed

Bleach will probably be your best bet. You don't need much a tablespoon in 5 gallons hot water overnight or longer will be all it takes.
Oxyclean or it's generic might also work.

If all methods fail, reserve your tun for belgian/lambic/sour beers. The critters left that you smell could be your house funkiness to make incredible beer.
That's the beauty of home brewing. The never ending quest of accumulating more brewing equipment.