rising problems with double recipe
Hello everybody. I apologize if this has been covered but I'm at work now and haven't had a chance to sift through the posts here yet. My problem is this: I had a bread recipe and it made nice bread. We decided that I would make all of our bread to avoid buying so i got two 12"x4.5"(I think that's right) pans so the loaves were more like store bought in shape. Basically I just doubled the recipe and while rising in the bowl it seems to rise fine but once I scale and pan them for the final rise(covered with a towel), it doesn't seem to get near the volume as half the recipe got in a regular loaf pan. I know some adjustments need to be made as the recipe scales up buy I assumed being such a small quantity it wouldn't be such a problem. The formula i use for two loaves is very basic:
850g bread flour
510g water
9g salt
4g yeast
It seems to rise ok until it gets to the top of the pans, could the towel be too heavy? I have made two batches and they both turned out the same way. I haven't tried making two batches with the original formula to see if that helps. I'm new to bread making and this has me a little aggravated. Thank you for any help.
Oh, the basic process is make the dough, let rise covered in a big bowl folding twice, weighing splitting in half, panning, covering for the final rise then 400 until golden, with steam at the beginning.