The Art of French Pastry

set, the product cannot be
re-melted; we call this
pectin irreversible. The
second one, called NH
pectin, is used in jellies
and clear glazes for pastry.
When you heat up a jelly it
usually re-melts; NH
pectin is reversible. Both
kinds of pectin keep well in
an airtight container at
room temperature.
Source: www.chefrubber.com