Desired DoughTemperature (DDT), at best only a gross-estimate of the temperature of a dough at the beginning of bulk fermentation (ref.: http://www.thefreshloaf.com/node/11719/ddt-calculation-question-daniel-t-dimuzio ) is too often ignored, or given only a brief word or two of non-specific, and often ambiguous explanation. (See, for example, BBA's Pain a l'Ancienne: this is the best I've found, and still, in my opinion, using ice-water is ambiguous in specificity, and lacks complete explanation, of effects and side-effects.)
Within the usual range of factors, i.e., the newly mixed dough's temperature, Ph, hydration, and ingredients present; dough temperature, more than any other factor, controls yeast and bacteria activity. Secondly, dough temperature is hard to change, and especially hard to change in a controlled way. Thirdly--and not an issue, but a reality--the home baker has more direct control over temperature than any other factor. (Ingredients is, of course, the second, but you can't turn a brioche into a ciabatta.)
Addressing the latter issue first, having recently built a proofing box, early experiences supported my concern that a dough's initial temperature would dominate the dough's average temperature for hours. Stated differently, the heat energy in a light bulb, or heating pad--typical heat sources in homemade proofing boxes--is low. Furthermore, the transfer of heat into a dough mass (a complex function of the dough's mass, surface area, temperature differences, and its specific heat) is slow.
This is not a bad thing. If the heat source is cranked up too high, undesired side-effects will likely occur; e.g., the dough's surface will dry out, yeast cells at or near the dough's surface will produce gas at a reduced rate. The solution to avoiding both these problems is straight forward: Set the DDT to the temperature desired for bulk fermentation. If your going to proof at 76°F (the most common temperature invoked by bread book formulae), 80*F (Tartine Bread). 82.5°F (Zojurishi bread machine pre-heat, and proof temperature most favorable to yeast growth and activity), or 90°F (best temperature favoring bacterial vs. yeast growth in most sourdough cultures.) adjust the mixes' water temperature to reach a DDT as close as possible to the intended bulk fermenting temperature. Conversely, 40°F if you're going to retard the dough in the refrigerator, and finish proofing at room temperture, or 55°F if your using a wine cooler--my preferred retarding temperature. Then your proofing box (or chiller) is maintaining the dough's initial temperature: a much less energetic job.
The first issue, also stated in a different way: why? What's the reason for a specific DDT? Flavor, Scheduling, or Texture? I can't think of a fourth reason, and texture is the most tenuous. Nonetheless, know why you've chosen a proofing temperature, and choose accordingly. And, if your writing a breadbook, fully explain why you chose a specificied initial dough temperature, including its benefits and downers.
David G
