Like other types of yeast leavened bread doughs, pizza doughs will benefit from fermenting for a period of time before using or baking. Fermentation provides dough conditioning, making the dough easier to shape. It also reduces the propensity of the dough to bubble during baking, and it does wonders for the flavor of the dough, too. Depending upon the temperature at which the dough is fermented, you can get different fermentation flavors. For example, if the dough is unusually soft, due to high absorption (added water), or if it is stored (fermented) in a cool environment, the yeast and bacteria present in the dough will tend to produce greater amounts of lactic acid, producing a flavor in the finished crust more along the lines of that of a sourdough. A dough that is made with a low absorption (50 percent or less), or which is allowed to ferment at room temperature, will tend to produce more acetic acid, resulting in a flavor more like that which we would associate with commercially produced white pan bread. This is one of the reasons why you see so many formulas/recipes for artisan bread that call for overnight refrigeration/ fermentation of the dough.
Fermentation itself is important to the performance of our pizza dough. The effects of fermentation combine to help mellow or weaken the gluten forming proteins, resulting in a finished dough that is more easily stretched to shape, and which doesn’t possess so much snap-back that it refuses to maintain its shape. The weakening effect upon the fl our proteins is also responsible for developing a more tender eating characteristic.
The main by-product of fermentation, carbon dioxide, works to leaven the dough both before and during baking. This leavening effect is what produces the desired lightness in the finished crust (which, in turn, is responsible to a great degree for the crispiness and crust color development of the finished crust).
Since so many good things come from the effects of fermentation, one might be inclined to think that more is better, but that isn’t necessarily the case — too much fermentation can result in a dough that is excessively gassy, or so weak that it is diffi cult to shape properly, not to mention the fact that it probably won’t rise very well either, and remember those acids that are formed as a by-product of fermentation? If your dough gets too acidic as a result of excessive fermentation, those acids will impede crust color development, making it difficult to get the desired color on the finished crust. Then, too, there is flavor –– an over fermented dough will have a very strong and pronounced “fermentation” smell. Some operators have likened this smell to that of a brewery, and they’re not too far off base, as the aromatics are both due to the by-products of yeast fermentation.
In some instances, we might see a dough that has not been given sufficient fermentation. Think of an emergency dough, where you came in to open the store early in the morning only to be met by the pungent smell of fermentation — and a mess in the cooler. Now you’re faced with the task of cleaning up the mess, tossing out the “blown” dough, and making an emergency dough to get you through the day. Since you will only have a few hours at most to get the emergency dough up and running, you can bet that it will be short on fermentation time.
Even though we double the yeast level in our emergency dough, the flavor will still be somewhat lacking. Because of the shorter fermentation time, the same level of acids won’t be developed, which can result in a dough that colors more quickly in the oven, possibly necessitating a slight reduction in bake time or temperature. And lastly, since the effect of the various acids and enzymes from the yeast haven’t had sufficient time to mellow, or soften the gluten forming proteins, the dough might feel a little stiffer or stronger, and exhibit more snap-back at forming than your regular doughs. To some extent, this can be compensated for through the addition of a small amount of L-cysteine/PZ-44 to the dough. Even at this, you will most likely find that the dough isn’t as light/ airy as your regular dough, and this can make the finished crust more chewy and less crispy.
As you can see, fermentation is a very important aspect of making a quality pizza/pizza crust. The main thing to keep in mind is that it isn’t so much a matter of how much fermentation you give the dough, but rather how well you control the fermentation.
Tom Lehmann is a director at the American Institute of Baking in Manhattan, Kansas.