Baking – When to add eggs in brioche

The main issue you will face is the extra mixing allows for additional gluten development. In some breads, this could create a risk of over-kneading, which could make the dough less workable, more prone to tearing, and more difficult to get the proper rise.

Challah is a basic egg enriched bread, so other than the eggs themselves (which are fairly effective at helping prevent over-kneading) you don't have a great deal of protection. The worst case scenario is that your bread will be a little flat and crumbly; the best case is that you are still well within the tolerance window and it will be just fine.

Edit: I will leave this for reference, but I was thinking of brioche: in a very sweet, fatty bread like brioche, this risk is minimized. The fat and sugars in the dough act as barriers preventing the glutin-precursors from interacting as frequently or as easily, making it much, much more difficult to over knead.

The main reasons for the traditional order of dough assembly are:

• As you no doubt realize, it is much easier to incorporate the liquids evenly into loose flour, rather than a partially formed dough
• The yeast acts on the ingredients present, so sometimes ingredients which inhibit yeast growth are held back until after a fermentation phase
• You want time for all of the flour to be fully hydrated--normally, in yeast raised doughs, this is hardly an issue.

I baked 3 or 4 loaves of challah last January over a month period to try and perfect a rainbow loaf of bread for a dinner party (Wizard of Oz and over the rainbow themed).

Loaf 1 I mixed ingrediants and worked the dough and then prior to kneading I used cake decorating gelled (Wilton brand) coloring. This required substantial kneading to fully integrate the coloring and probably caused the loaf to not rise properly from over work or inconsistent gluten formation.

Subsequent loaves required making the water and yeast mixture and dripping in 5-35 drops of liquid food coloring into measured amounts of liquid by weight. Each liquid amount depending on rainbow location varied and the apparent strength of the drops did too. The liquid mixture then had a consistent bright color and adding in the sugar, salt and flour proved to make for a consistent color shading throughout. The minimal quantity of the alcohol/glycol based coloring didn't appear to affect the texture and the need to over work the dough was lessened since the color was consistent from the beginning.

Using up to 7 different colors in 1 large loaf (both rainbow shaped in a large baked bowl and in a braided roll) did require a bit more effort than making 1 batch of dough and separating briefly after kneading to add color. However the effort was well worth it!