I've been baking the multigrain struan from Reinhart's Whole Grain Baking book, and while the flavor is excellent, the crumb has a tendency to fall apart. I know this is multigrain--but still.  It works best when the soaker is uncooked millet, quinoa,  cooked rice, oats, worse when the soaker contains a lot of cornmeal. I'm cooking by weights, so not sure what the problem is.  I've also had to increase the kneading time to 8 minutes, or the thing falls apart even more.  Any suggestions on ways to get the bread more solid, less crumbly?
        

Although I haven't made this particular bread, I have made breads along the same lines. Knead it longer, and/or use a whole wheat flour that has a higher protein content, such as Wheat Montana's. You can also use a small amount of wheat gluten if you like.
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