BBA Poolish Baguettes

Happy weekend! I made baguettes for the first time in a long time today. BBA's poolish baguettes. One mistake...the recipe, er formula, calls for 7 oz. of poolish. I made half a recipe of poolish from the book, which is really more like 11 oz., and dumped it all into the final dough. ooooops. But what are you gonna do with 4 oz. of leftover poolish?

This dough gets 4 hours of fermentation and about an hour of proofing. The baguettes came out sorta pretty, I thought:

I describe the flavor as 'clean', not at all yeasty, just wheaty. Very nice. PR recommends sifting 1.75c of whole wheat flour to replicate the ash content of the European flour used in the original formula. When I sifted my KA whole wheat, almost none of the bran was left in the sifter, so I used his second suggestion: using only a few tablespoons of WWF, and unbleached for the remainder of the dough. The bread still had plenty of identifiable bran in it. The bread is very lightly salted. I'm really happy with the flavor and texture.

But here's my question. As you can see, my slashes filled in to bring the exposed dough up to the level of the crust. There are no 'ears'. This has been the case with most of my breads. I did the PR technique of pouring 6-8 oz. of boiling water into a cast iron pan in the bottom of my oven, but no other steaming or spraying beyond that. If you look at some other baguettes on TFL, like these or these, there are definite sharply-defined ears. It's a minor thing, since I'm happy with the way this bread turned out, but I'm just curious as to what is keeping this from happening on my breads. Any ideas?

Sue