Dried Isinglass: does it go off?

[JackA]

The yeast I like to use is a bit troublesome and always need some encouragement to drop. Previously I've used some dried Isinglass which did the trick. According to the packet, it's now out of date (BBE Feb 11). I've been trying to clear two cornies with this stuff but it doesn't seem to be working. The only other thing I can think of is a chill haze - I've put both cornies in a fridge. Quick question: if I draw off half a pint and leave it to warm up, will the chill haze subside? I'd like to rule this out before blaming the isinglass!

Thanks

[crookedeyeboy]

If the haze is protein then yes warming it up will dissolve the proteins back into solution.
The Isinglass doesnt 'go off' as such all the happens is the activity drops off so its not quite as strong but Ive yet to see any six month old isinglass, liquir or dried, NOT clear a beer! I would assume your issue is with protein.
Have you got any auxiliary finings?