er, 193F? somethings not right here...
found this on ehow:
Find the published DDT (Desired Dough Temperature). This may be the hardest part of the process if the recipe you are using does not list a DDT. If you’re following a recipe without a listed DDT, try checking similar professional recipes and use their DDT for your own. If you can’t find a published DDT, try using 78 degrees. Most amateur baking recipes do not list a DDT.
Calculate the Total Temperature Factor (TTF). The TTF is simply the DDT multiplied by the number of known temperature factors involved. There are only 3 known temperature factors; flour temperature, room temperature and mixer friction. Therefore, to calculate the TTF, you will multiply the DDT by 3. For this example, we will use 78 degrees for the DDT. 78 times 3 equals 234. Therefore, the TTF is 234.
Determine the mixer friction value. Because movement generates heat, we must allow for the friction of the mixer when calculating our working dough temperature. Baking professionals give every minute a mixer is used a value of 2. Therefore, if your recipe calls for you to mix the dough in the mixer for 8 minutes, you will multiply 8 times 2 and have a mixer friction value of 16.
Add all the known temperature factors. Now, we have the mixer friction value and it’s easy to get the flour temperature and the room temperature with everyday thermometers. For this example, we’ll use a flour temperature of 60 degrees, and a room temperature of 70 degrees. By adding 16 plus 60 plus 70, we arrive at the number 146. Therefore, 146 is the sum of all known temperature factors.
Find the necessary temperature of the water by subtracting the sum of all known temperature factors from the TTF. The TTF we calculated in Step 2 was 234 and the sum of known temperatures factors was 146. After subtracting 146 from 234, we have the number 88. Therefore, you should use water that is exactly 88 degrees in temperature when making your dough.
Use the same equation every time you make your baked yeast product for uniform results. Professional bakers calculate the DDT every time they make dough for bread or baked goods. It's nice to know that you have control of the consistency of your dough. If you bake yeast products to sell, it's imperative.
Maybe Peter or someone who loves tinkering with math could refine this further...