Challah or hallah is a traditional Jewish bread eaten on Shabbat and Jewish holidays (except Passover, when leavened bread is not allowed). This association with Judaism is most prevalent in the United States, as challah is also a traditional bread in numerous European countries, such as Hungary, among local non-Jewish peasant populations.

Also see:  Challah Recipes

Ingredients

• Yeast is a living organism needing warmth and water to grow.  It makes the dough rise by giving off gas that expands the cells held together by the gluten.  Sugar speeds up this process.  Salt slows it down.
• Salt inhibits yeast.  Too much salt slows it action, too little salt allows the yeast to expand before the flavor has developed.  Salt also give bread a good flavor and acts as a preservative.
• Sweeteners, such as sugar or honey, are food for the yeast.  A little bit of sweetener feeds the yeast, while a little more gives a sweet flavor without harming the growth of the yeast.  More sugar will make the yeast grow faster, but too much will slow it down.  Sweet breads generally require more yeast to compensate for the extra sugar.  Sugar will also give a browner crust.
• Flour is the body of the bread.  The amount of flow needed for a particular recipes will vary because the amount of water the flour absorbs is not constant.  It will vary according to the weather on the day you are baking, the variety of wheat used, and when the wheat was harvested.
• Gluten, found in the innermost part of the wheat, holds everything together.  The yeast gives off gas that expands, the cells.  Gluten then holds them in the expanded condition.  It is developed by mixing, kneading and rising.  Underdeveloped gluten will give a heavier loaf.  The amount of gluten in different types of flour is in descending order as follows: gluten four, bread flour, all purpose white flour, whole-flour, rye flour.
• Eggs and Oil, add richness to the Challah or bread and act as a preservative.  They also shorten the gluten strands, giving a more tender texture.

When opening eggs examine each one before combing with the recipe to make sure there are no blood spots.  If a blood spot is found, discard the egg, and rinse out the cup or dish with cold water.