I believe if you mix them in very gently just at the very end you can reduce the purple coloring. I doubt you'll completely remove it though: that is the oil leaking out of the walnuts. I actually find it quite attractive looking.

 This is my walnut and Guinness bread to which I also added walnut oil... qahtan

Hi,

I love using toasted walnuts in the Glezer and Hamelman pain levains.  Yes, they make for interesting looking bread. I usually use them in conjunction with craisins, raisins or currants.  Always very popular loaves, and I've never heard a negative word about the color.

 Sylvia

I haven't tried walnut bread, but I did adapt a method from Cook's Illustrated's recent kalamata olive bread.  They recommended folding in the olives in during the bulk fermentation.  I mixed up some wet sourdough and kneaded briefly in the mixer.  Then I did two folds during the fermentation, adding the olives during the first so they got reasonably mixed.  I poured the dough onto a well-floured counter, spread it gently, then placed the olives on top.  Then I made a standard fold (stretching and folding each of the four quarters over the center).  I returned the dough to the bowl for an hour, and folded it again.  This kept the olives from breaking up or staining the dough.  It also kept them mostly inside the loaf so they didn't get burned when I baked it (I ended up making fougasse with this particular one).  This technique would probably work for adding things to any dough if  you want to avoid mixing it in during kneading.

Thanks for the help! 

Zolablue, I make that blue cheese walnut bread (I renamed it Rhapsody in Bleu) and for me, it has a slightly bluish color.  While I'm mixing it up, however, it has a rather unappealing gray tone to it.  I use Gorgonzola, if that makes a difference.  Also, I made it once as he described and was totally put off by the flavor and the smell (overpoweringly sour).  I now add 1 t instant yeast to the dough and talk about divine....I have a home-based baking business where I live (yay for VA where it's legal!) and I have a couple of loaves just baked of my Rhapsody in Bleu waiting to go. 

Sorry about that little tangent--I love that bread!

In regards to the purple of the walnuts, this time when I toasted them, I rubbed them in a dishcloth to get most of the skins off--a rather messy job, but it did work better.  I like the idea of gently folding them in during the bulk fermentation.  I'll try that next time. 

That bread uses a barm so are you saying you simply replace the barm with the instant yeast?  I love your name for it!  I'm even more anxious to try it now.  Trouble is I don't love walnuts and hubby doesn't love blue cheese but I'm so in love with the color I just gotta do it. :o)

blue cheese and walnut bread is simply the best thing in the world. forget that you don't love walnuts and forget your husband doesn't love blue cheese. I usually make this bread with a very high poolish percentage which i find compliments the cheese's sharpness with its own. I usually use danish blue because it's a lot cheaper than gorganzola and really melts into the dough nicely. also, concerning the discoloring caused my the walnuts: i usually wait until i shape my loaves to add the cheese and walnuts, making kind of a cinnamon roll style log with closed ends and I've never had purple loaves with that method. I'm also keen on shaping my loaves this way because it eliminates hunks of blue cheese or walnuts on the crust and the cheese and walnuts fountain out of the score marks in the oven in a really beautiful way.

Zolablue--I use the barm and 1 t yeast.  I use 20 oz bread flour, 6 oz walnuts, 5 oz gorgonzola (the cheapest blue cheese where I live), 1 3/4 c water, the 1 t yeast, salt (1 1/2 t I think) and the barm.  Outstanding!