I've been thinking of splitting a 3.15lb NB container of Munich LME between a couple of BCS recipes that call for small amounts of the stuff. That probably means having an open container of LME around for a week or two. If I put it in the fridge, how soon do I need to worry about staling? Any suggestions as to how I can keep it as fresh as possible??

Most of the stuff I have read states a shelf live of 3 - 6 months for LME.
However, that is dependant on the how old it is from the manufacturer.

For opened LME? I doubt that it will stay good for that long opened. I've used the Briess products in the screwtop canisters and drop them in the chest freezer between brews I need them for.

I've heard if you pour some vodka on the surface it will keep the baddies at bay.
Good luck!

Sorry guess I should have stated that I am making the assumption that the LME is closed off from air after it has been opened. Either a lid placed back on it, or that it is transferred to a container that can be sealed up again.

Well, even if it's reclosed, it would have been exposed to the air... not sure what will grow on that concentrated of a sugar though...

I'd imagine it'd come down to staling before contamination. It's going to get boiled anyhow.

To answer the original question, I have no idea. I've always used DME when using extract & that stuff stays good in a tupperware container stored in the cabinet.

that's a good point that on the staling/oxidation... even if freezing doesn't make much difference as far as critters goes, it should be slowing down chemical reactions.