Lots of tomato sauce made over the years and I honestly can say I've never seen anything like you describe. Can't imagine what it might be either. Only thing that comes to mind is seeds that may have germinated inside the tomatoes - that happens now and then.

What does the inside of one of the tomatoes look like when sliced? What variety of tomato? How are you processing them - Foley, mill, chinnois - and with what steps? Is it possible the fibers came from your tomato mill or other kitchen tools?

Dave

Could they be cloth fibers from whatever you dried the mill (or processor) with? If you get a chance, take a picture of the white fibers. That would be very helpful.

Here is a link that might be useful: Kim's Vegetable and Flower Garden

I sometimes get white things like you describe when I run cooked tomatoes through a hand turned food mill....more so when I work hard and try to get every last bit of puree I can out of the glop left in the mill. I always figured it was part of the seed and didn't worry about it. Sometimes I'll run cooked tomatoes through the blender. Seems like I remember getting the white things at times that way, too.....it's been awhile since I've done that, though, so the memory is kinda foggy.