Hi, docpat.

Some factors that might cause that problem would be too much gluten (maybe use less bread flour?), low hydration and/or insufficient fermentation or proofing. 
Just semi-educated guesses.
David

Hi Docpat,

This is just an idea, but maybe you could try taking the loaf out of the oven a few minutes earlier. I've found that bread I plan on eating toasted is better if I don't keep it in the oven for it to fully bake. I don't mean par-bake, but just those few extra minutes. 

Hope it helps a bit :-)

L_M

 Good morning Docpat,

Here's a "for what it's worth" analysis.  In my experience breads made using a preferment (poolish, biga) usually do not toast very well in that they tend to toughen when toasted and don't usually brown evenly.  Although I am not a chemist my guess is that it has something to do with the preferment process and the method of baking prefermented loaves. 

On the other hand breads I have made using the direct method (yeast does all the work, no preferment) do much better when toasted.  For example: I have had a similar experience to yours when toasting artisan breads however, when I toast bread that I have made using the direct method (yeast only with 2 knockdowns with a final rising in the pan, then into the oven) they toast much more evenly and hold their moisture better, without drying out. 

holds99

Holds99;

Your FWI was RO (right on). I have made the same recipe three times now without the preferment and the rogels (cross between a roll and a bagel) are toasting up beautifuly. Thanks for your suggestion.