I have dried home made hide/sinew glue for longterm storage. The best way to do it is in small batches. Warm and thin the glue until it runs like thin syrup. Pour it onto any flat surface that will hold it, such as cookie sheets, plates, SilPat baking sheets. Pour only enough that it does not cover the entire surface so that it can spread itself as thin as it is able. Let it gel as it cools. Allow it to dry until you can peel it up as a sheet.
Now place those rubbery thin sheets on racks or wire mesh (I have used old screen windows propped on blocks to allow air flow in, around, under, etc) and place a fan in the room to move the air. You know they are thin enough that once they have dried for 24 hours, you can crumbled them in your hands like potato chips. Crush it up and leave exposed to moving air for another 24 hours at least. Then store in plastic tubs in the freezer.
If you think you are going to skip the step of removing the thin rubbery sheets from the cookie sheets/whatever, you are an idiot. I ruined two BRAND NEW GLASS BAKING DISHES doing this. The hide glue will mechanically bond to microscopic pitting in the surface of the glass and as it shrinks, it will literally knap flakes of glass off as it contracts!!! It will peel up the nonstick coating of cookie sheets, and destroy the glaze on crockery and pottery! And that, kiddies, is why it works so bloody danged good on wood and sinew....it has even more porosity, and consequently even better mechanical adhesion.
The best I have found are the SilPat cookie sheets. I dropped $30 on a silicone baking sheet and NOTHING sticks to it, not even burnt on fake cheese from crappy frozen pizza!