I mixed glue in the pot once.  The clean up was such a labor intensive
operation that I knew there had to be a better way.

The little light in my head clicked on when a tech told me to mix the
glue in a jar and place the jar in the pot as a  water bath.  The jar
can be removed, capped and stored in the refrigerator for the next use.
It can be re-heated three times then discard.

What I do with the excess of the first heating (unless I will use it
again relatively soon) is allow it to gel and break it into cubes.
These are placed in a plastic bag and frozen.  Now, if I need a little
glue, I take out the necessary amount and 12+ seconds in the microwave
rejuvenates it.  I keep two batches, one regular and one mixed with
whitening for spot ivory re-gluing.

Jon Page
Harwich Port, Cape Cod, Mass.