CÁCH TÍNH NHIỆT ĐỘ NƯỚC TRỘN HOW TO CALCULATE THE MIXING WATER TEMPERATURE

HOW TO CALCULATE THE MIXING WATER TEMPERATURE

To help determine the mixing water temperature, a simple calculation can be performed. This quick calculation considers the various temperatures that factor into a dough mix: the flour, levain, ambient, and the friction factor if using a mechanical mixer (see What Is Friction Factor?, this page ). This calculation is not an end-all calculation; it glosses over many things (such as the mass of the ingredients: a larger amount of water will have more impact when heated if the flour and levain are small by comparison), but it’s a great rough starting point. It’s also very handy if you’re baking somewhere away from home and need a guidepost from which to start. I also find it helpful to take note of the temperature of your mixing water and the final dough temperature, which will help you dial in future bakes.

Let’s Look at an Example

A recipe’s desired dough temperature is 78°F (25°C), which is common in this book. We’ll assume the flour temperature is the same as the ambient temperature of your kitchen, and for this example, we’ll say 72°F (22°C) for both. For the levain temperature (which you can quickly measure with an instant-read thermometer), we’ll go with 78°F (25°C) since that’s what I typically call for in recipes throughout this book. Finally, the friction factor will be 0 since we are mixing the dough by hand.

The result of plugging in the numbers and running the quick calculation is 90°F (32°C)—the temperature to which we need to warm our water in order to reach the desired dough temperature of 78°F (25°C).

Help! I Hate Math. What Do I Do?

If you really don’t want to do any calculations, use this cheat sheet: Most of the recipes in this book have a desired dough temperature (DDT) of 78°F (25°C). Since the kitchen temperature usually has the largest impact, we use that and the fact that the pre-ferment (levain) will also be 78°F (25°C) to arrive at the following table (using the DDT calculation, this page ):

Calculations for a DDT of 78°F (25°C) assuming hand mixing and that the levain temperature is around 78°F (25°C).

WHAT IS FRICTION FACTOR?

The friction factor represents the amount of heat generated when mixing a dough mechanically (it’s a representation of the conversion of kinetic energy into thermal energy—i.e., heat). When mixing dough by hand, this is typically set to 0 because mixing by hand isn’t vigorous enough to significantly increase the temperature of the dough (in fact, it might cool the dough in the winter). Ultimately, the friction factor is found through experimentation with your mixer because each is different. To determine the friction factor, take the temperature of the dough before mixing, proceed with your usual mix time and speed, then measure the temperature when mixing is finished. Note the difference in degrees and you have your friction factor. For a KitchenAid running on low speed (“Stir”) for 2 to 3 minutes, then medium speed (“2”) for 3 to 4 minutes, I find a friction factor of about 20°F/10°C. Use this number in the future for this calculation—if your mixing speed and times are consistent, so, too, will the friction factor be. Over time, you’ll internalize the effect your mixer has on your dough and how to adjust your mixing water temperature to compensate.