How long will unopened commercial thai chili pastes last?
My pantry has about a dozen containers of curry pastes that I bought before moving to this current address in 2005. They are plastic tubs, jars, or little cans of Maesri and Mae Ploy Green Curry Paste, Panang Curry, Chili/Garlic Paste, etc.
Their "expiration" dates range from 2007-08. But do these things actually go bad in a health sense (I understand that they might well not be spanking fresh)? I've started back in on Thai ingredients recipes, so I'm just wondering...
I don't know about expired (I've never checked.)
I have kept Maesri canned pastes opened, and only covered w/ tin foil and a loose rubber band though for months and months. Areas around the side actually turned black (I'm guessing from oxygen exposure)... I just scooped off the black and the top layer, and used it w/o any problems. Depends on the paste though, some are solely plant material, some have fish or crustacean ingredients and some have more oil which helps bad stuff culture.
I have a similar senario in my cupboard, Mae Ploy Green and Red Curry paste in tubs, unopened, sealed in a plastic bag inside the tub, expiration date 1/24/2010. The stuff still looks fine to me and I have no qualms about using it (someday.) Your stuff is definitely older but my feeling is that, aside from possibly losing some flavor, this product really never goes over the edge, especially the cans.
I also have a two year old sealed jar of Huy Fong Sambal Oelek, refrierated from the day it arrived, with no noticable change in color.
Here's a thread on curry paste longevity after it's been opened: