"Doug" > wrote in message
news:k210j.4497$701.2375@trndny08...
>A few months ago I bought some white miso paste (in a vacuum sealed plastic
>bag). Since opening it, I've kept it in its original container inside a
>ziplock type plastic bag in my household refrigerator.
>
> How long will this product be good, and safe to use? I'm hoping the answer
> is "forever", but alas, wishing won't make it so!
>
> Thanks in advance.

Believe it or not your answer is actually fairly close
as far as food goes.
Two years ago a Japanese TV program did a casual
examination of how long certain foods would keep.
The oldest item was a small tub of Miso which had been
kept in a cool , but not refrigerated or frozen, state
for 30 years. It was tested as safe and edible by food research specialists
then actually tasted by people on the TV show. It had turned a dark brown
and with it's crusty exterior it had a rather disgusting appearance.
It was described as "very salty".

In Japan foods have two labels "Shoumi Kigen"
meaning "Time limit for enjoyable (taste) consumption"
and "Shouhi Kigen" meaning "Time limit for consumption".

In the case of Miso, it certainly remains edible for a
ridiculously long time but even with air tight enclosure and
refrigeration I would suspect that the "Taste" is good
for a few months perhaps a year.

Musashi