Is Warm Liquid Optional When Baking Bread?
Many bread recipes call for heating the milk (or another liquid) before combining it with the yeast. Is this step optional?
Yeast is most active when warm (not hot), so our recipes call for 110-degree liquid to ensure that the resulting dough is hospitable to the yeast. But using warm liquid isn’t the only way to warm your dough; kneading either by hand or in a mixer creates friction, which warms the dough. If one's kitchen and ingredients are already relatively warm, the dough may rise perfectly well without any help from warm liquid.
Also, our bread recipes call for instant or rapid-rise yeast, which is mixed with the dry ingredients. Instant and rapid-rise yeasts are dried more gently and in smaller particles than traditional active dry yeast, so there are more live cells and the smaller granules absorb water and begin working more quickly. Thus, the jump start from warm liquid is not essential. However, using the recommended temperature in a given recipe will make it more likely that the dough will rise in the amount of time specified, which eliminates some of the guesswork.
We made two loaves of sandwich bread, one with 110-degree milk (as per the recipe) and the other with milk straight from the refrigerator. Given the same hour-long first rise, the dough made with warm milk rose much higher. But in the second rise, the dough made with cold milk caught up, and both baked loaves turned out the same height. When we tasted them side by side, we noticed that the bread made with warm milk had a slightly stronger yeast flavor, which some tasters preferred.
THE BOTTOM LINE: When using recipes that call for instant or rapid-rise yeast, you don’t need to use warm liquid, although it will speed the initial rise.