A friend of mine showed me a bottle of Franklin/Titebond Liquid Hide Glue with an old expiration date and he thought it was still good. I looked at the date and it was 7-01 and I thought there was no way it was any good. So I did the finger/thumb test and sure enough it exhibited ‘legging’ or ‘cottoning’ indicating it was still good.
So the following day I conducted the only sanction test for testing the usefullness of liquid hide glue, a bead of glue on paper, cooked in a 150 degree [F] oven for 15 to 20 minutes and allowed to cool. To my surprise it cracked indicating it was still good.
It had not been stored in special conditions although the shop never got real hot. Good idea to test before you throw it away.