Omid do you recommend adding baker's yeast to my sourdough starter or adding both to my pizza dough? I use both camldoli and ischia starters. they don't give me as much rise as using baker's yeast alone. I appreciate your thoughts.
Experiment with your fermentation process. You don't need baker's yeast to get the rise you want.
Dear Pulcinella, I am not sure if I qualify to answer your questions, so please be mindful of what I relate here. First, I am agreeable to dear Craig's above-referenced position. One thought, only a thought, that immediately comes to my mind is that, if you add baker's yeast to your sourdough culture or to your sourdough pizza dough, then you may inauspiciously alter the microbial ecosystem of your culture or dough; e.g., the culture's wild yeasts and the baker's yeasts (i.e., Saccharomyces cerevisiae
) may compete over the vital resources (the sugars) critical to their biological survival. (By analogy, think about the political conflicts that have transpired as results of the United States, Great Britain, Russia, and China trying to dominate the oil resources around the globe!) If there is truth to this hypothetical model, and the baker's yeasts dominate the sourdough environment, then the essential biogenic symbiosis between the culture's original bacteria and wild yeasts may be at risk!
Yet, there are pizzerias that routinely add both sourdough culture (supposedly for the sake of its flavor, exoticism, and/or publicity-boost) and baker's yeast (mainly for its leavening boost) to their doughs. (Additionally, some pizzerias claim or generalize that the American taste buds are addicted
to and demand
the taste of commercial yeast dough.) My idea is that, if your Camaldoli or Ischia culture is properly constituted (particularly in terms of the ratio of the autochthonous microflora that flourish in it) and is properly applied and managed thereon, then the addition of baker's yeast is superfluous, and that your dough should rise satisfactorily without it.
Of course, formulation and maintenance of a well-balanced starter culture is a prerequisite task
. Proper refreshment of your culture, the amount you discard thereof prior to refreshing, the water-flour ratio (relative to the remaining culture) you use to replenish the culture, the way you mix and incorporate them into a particular consistency, the ambient temperature you maintain during the cultivation, the uniformity of the growth cycles of the culture, timely refreshment cycles of the culture, how pristine you keep the culture, and etc.—they all can impact the lactic and leavening proclivity of your culture.
Perhaps, Dr. Ed Wood (the gentleman who collects, cultivates, and sells various sourdough starters—including the Camaldoli and Ischia that were entrusted to him by Mr. Marco Parente—at http://www.sourdo.com
) can give us some advice. According to the first edition of his book Classic Sourdough
(of which there is currently a revised edition):
"We know the sourdough process results from the fermentation reactions of two quite different classes of microorganisms, wild yeast and beneficial bacteria. . . . I place particular emphasis on the term wild
since the commercial bread industry has developed new yeast strains that are incompatible with sourdoughs. Why incompatible?
The new yeasts [i.e., the commercial or baker's yeast] ferment so rapidly that the dough is leavened and baked before the bacteria have time to produce the sourdough flavor. Commercial bakers love saving time since it is possible to produce more bread at less cost and more profit. But the loss of sourdough flavor and texture means the total loss of sourdoughs, as I define them, and the result is inferior bread. . . .
In the early 1800s, Pasteur looked into a microscope and saw what we now call wild yeast and discovered for the first time what really made bread dough rise. About a hundred years later researchers learned how to select, isolate, and grow single strains of yeast in pure cultures. They searched for and found species of Saccharomyces cerevisiae
, baker's yeast, that [predictably] leavened bread doughs with incredible speed and [uniformity].
Then the industrial revolution took bread out of the home and put it in factories that manufacture something labeled 'bread' that neither looks like nor tastes like the staff of life. Breads began to be produced by mammoth machines. Sourdough starters were no longer used, small town bakeries disappeared, people stopped baking in their home, and the staff of life became neither delicious nor nutritious. Bakers thought the need for sourdough cultures was gone forever, but they were wrong. Baker's yeast is totally incapable of producing the sourdough flavor and without the lactobacilli the quality of breads has never been the same. . . .
Bakers of every sort welcomed the introduction of commercial yeast in the late 1800s. It greatly simplified the baking process and made it much faster. But something happened to the sourdough flavor. It disappeared! In due time, researchers identified the problem. They found that sourdough bread is the product of not one microorganism but two: Wild yeasts make it rise and beneficial bacteria provide the flavor. These bacteria are primarily lactobacilli, so named because they produce lactic acid, which contributes to the sour flavor. They don't do it very fast. It requires approximately twelve hours for the bacteria to develop fully the authentic taste of sourdough, depending on the temperature of the dough. Extremely fast commercial yeasts, particularly active dry yeast, have shortened the rising process to two hours or less, giving the lactobacilli little chance to get started.
Huge baking machines now dominate the production of bread. In addition, the baking industry adds a plethora of chemicals to change the physical characteristics of flour and dough to improve their 'machinability.' These include surface-active agents (surfactants) to help doughs go through machinery without sticking or tearing, other chemicals to soften the final bread texture or strengthen the dough by modifying the gluten, and a host of emulsifiers just to improve the mixing characteristics or increase shelf life. All of these special additives have one thing in common: No, or very limited, nutritional value. . . .
In 1676, a Dutch lens grinder, Anton van Leewenhoek, first observed and described microscopic life, and in 1680 produced the first sketches of yeast in beer. But nothing more happened for the next 170 years. The first alternative to wild sourdough yeast was obtained from beer foam. Then came Louis Pasteur in 1857, with his proof that fermentation is caused by yeast. A comprehensive system of yeast classification, which we still use, was published in 1896.
With Pasteur's discovery, a whole new field of yeast technology and cereal chemistry came to life. Microbiologists learned how to isolate single yeast cells and to select pure cultures. They selectively bred wild strains to develop yeast cells that leavened faster, were more tolerant to temperature change, and were easier to produce commercially. Mass-produced cakes of pressed yeast and packages of active dried yeast contained billions of cells that were all exactly alike. These purified strains are now carefully guarded to prevent contamination by wild types. . . .
. . . Now a handful of very large bakeries produce more than three-fourths of all bread sold in the United States. These same 'advances' have also led to much of modern bread having the flavor of an edible napkin. . . .It is important to understand the basic differences between the wild yeasts of sourdough and the commercial baker's yeast used in most other breads.
●First, sourdough yeasts grow best in acidic doughs, while baker's yeast does better in neutral or slightly alkaline doughs.
●Baker's yeast is a single species, Saccharomyces cerevisiae
, with hundreds of strains and varieties, while sourdoughs are usually leavened by one or more species in the same dough, none of which is baker's yeast.
●Baker's yeast is a highly uniform product that produces an equally uniform texture in bread dough. The wild yeasts are anything but uniform, and they vary from country to country.
●In one gram of commercial cake yeast there are twenty to twenty-four billion individual yeast cells; in a package of dry yeast there are 130 billion. By comparison, a cup of sourdough culture as it comes from the refrigerator contains far fewer cells. . . .
●But the most impressive difference between the two yeast types is that a single package of instant dried yeast produces just one batch of bread, while the same amount of wild sourdough culture produces loaf after loaf for the lifetimes of many bakers. . . .
This book emphasizes repeatedly that you should never use baker's yeast either in your sourdough culture or in the recipe of your sourdough bread. The addition of baker's yeast to a culture may overwhelm the wild yeast and destroy the culture. In addition, you risk the introduction of a bacteriophage [a virus that parasitizes a bacterium by infecting it and reproducing inside it], or virus, to which the commercial cells are immune but that may kill wild yeast.
Plus, if you leaven your dough with baker's yeast, the open texture characteristic of sourdough may disappear. The primary secret of sourdough success lies in the art of stimulating the wild culture, just before you use it in baking, into a burst of activity to equal the number of yeast cells found in commercial yeast.
The steps of preparing the culture described in Chapter 3 do just that!"
At last, I invite your attention to my previous supplementary posts:http://www.pizzamaking.com/forum/index.php/topic,14506.msg179245.html#msg179245http://www.pizzamaking.com/forum/index.php/topic,14506.msg179445.html#msg179445http://www.pizzamaking.com/forum/index.php/topic,14249.msg179836.html#msg179836
Have a great weekend.