Is it important to warm the flour before making bread?

One kitchen I used to work in had a dry store that was basically a shed and in winter when the flour would be particularly cold we would always warm the flour before making bread. It always worked beautifully. The thing is you're looking for the overall best temperature for your dough for the yeast to be active. So it's no good mixing warmish water with cold flour - your dough temp will keep the yeast sluggish. That was our theory anyway.

I beleive this to have some historical base (no citation just me) as historically, storage of flour in underheated homes was in cooler areas, or in a dark/cool place such as a cellar (in quantity) and adding enough heat (via water source) is insufficient to obtain a nice even yeast growth from a starter (also cool).

I say this as my great grandmother used to move her flour and she said this gave a more even texture (less holes) while having fluffy bread as it was stored in an unheated room - which also helped protect it from insects during long storage terms - this was a LONG time ago when I was a kid so I don't remember the exact way she said it.

EDIT: Just a thought: I wonder if kneeding on a warmed surface such as a granite block would do the same thing? Now I have a reason to install high-end counter tops? :)

This is interesting- I've never heard of a bread recipe that called for warming the flour. Smooth and elastic is primarily a function of flour/water ratio and kneading.

Warmth may make a difference in texture but it's biggest impact is in promoting yeast growth.

Rather than warming the flour, I warm the water in the microwave for a minute before adding to the recipe. Make sure it isn't so hot that it will kill the yeast.

I have never warmed the flour for baking solely to warm the flour, but I have toasted the flower to a light gold in the oven before using. (I let it cool down somewhat to avoid yeast genocide). The flavour difference was lovely; the bread ended up with a deeper, nuttier tone. The texture, however, seemed to be slightly affected; a bit dry.

The only thing I can think of w/r/t warming the flour is that warm starches gelate better than cold. Certainly none of the bakers I have worked with (including one whose obsession with croissants went as far as changing baking times by thirty seconds and oven moisture adjusted by single percentage points) have warmed their flour before baking with it. McGee also seems to be silent on the subject.

I also haven't heard about warming the flour. Do you have a thermometer to check what temperature your flour is before and after warming? If you store it in the fridge or outside that could explain the difference...

My guess is that it may be safer to warm the flour than the water, which risks killing the yeast. Safer doesn't mean faster or cheaper. Bakers, more conscious of the cost, heat the water.

In general, the optimal value for the dough is about 75F, some books give you different values for different breads. There are some formulas to know how hot or cold should be the water. Basically, you want to average the temperature of the flour, room and water to be 75F (yes, there is less water than flour, but kneading will give you some heat).

Elizabeth David's English Bread and Yeast Cookery (from the 1980s) recommends warming flour before bread baking. Besides revolutionizing the cooking in her country, she was a thorough food historian, and she quoted older sources (1930s) that recommended doing it, at least in a bakery setting. I always warm my flour before making bread because she recommended it.

Here's some more info about Julio's answer.

Ideal dough temperature is 75F, and kneading can add 10-30 degrees depending on a lot of different factors. The way to keep your dough the right temp is to adjust the water temp. The formula to figure out how hot your water should be for a sourdough according to King Arthur Flour Whole Grain Baking:

Water Temperature = (4x Desired Dough Temp.) - (Flour Temp. + Room Temp. + Starter Temp. + Friction)

I'm not 100% sure how to tell exactly how hot friction is, but in their examples In summer using a mixer friction is 26F and in winter using your hands is 12F.

Their example math is:

Summer

(4x75)-(80+85+75+26)

300 - 266

Water Temp = 34F

Winter

(4x75)-(65+65+68+12)

300-210

Water Temp = 90F

I think you can use this for regular doughs by changing it to

(3 x desired dough temp) - (Flour Temp. + Room Temp + Friction)

but I'm no math whiz, and I honestly don't worry too much about exact temperatures

No, you shouldn't warm it, it is counterproductive.

Current research shows that, the colder your dough, the better your gluten formation. I even once tried making bread with slush instead of water - together with a few other tricks (vitamin C, sufficient kneading in the pull-stretch method) I was able to make bread with 80% hydration from AP flour, without it forming a wet flop.

I don't know how the practice started, maybe out of the fact that the warmer the dough, the quicker the rising times, and many home bakers appreciate speedy rising. But cold kneading (and subsequent retarding in a cold environment, if possible) yields better quality bread. So, if your flour is cold, I suggest that you work with it as it is. If you want quick rising at the expense of taste and texture, a combination of room temperature flour and 35 Celsius warm water work well and is easier to achieve.

I put the flour in the microwave.... 4 cups, 1 minute, perfect!

A recipe for Whole wheat bread from Lehman's in Kidron, Ohio (a store that sells a lot to the Amish and does things in an old-fashioned way) calls for warming the flour...but doesn't say how, exactly, to do that.