Bread-Bakers v108.n013.3

Hi All!

I'm new to bread baking and have questions about vital wheat gluten. 
I bought some about a year ago from the bulk bins at my supermarket 
and have been storing it at room temp. in a glass jar.  Is this ok? 
Does it turn rancid like whole wheat flour and should be stored in the freezer?

Does every bread baker keep some on hand?  When do you use it and how 
do you know how much to add to your recipe?

Thanks a bunch!

Linda