Bread-Bakers v101.n006.16

I, too, have Tupperware bread keepers that I dearly love.  Like yourself, I 
found it a little short, however, for oven-baked loaves.  Go back to the 
Tupperware web side & purchase another, taller bottom for your keeper.  I 
believe they are called Square Keepers & I think the size was number 4 that 
I graduated up to (but check the size before buying).  That solved all my 
problems.

Sherry in Charlotte