Spelt protein, however, is seemingly tolerated better by people with wheat allergies. Spelt flour can be substituted for wheat flour in recipes.
Understanding Baking: The Art and Science of Baking and millions of other books are available for Amazon Kindle. Understanding Baking: The Art and Science of Baking Paperback – September 23, That's why, in addition to mastering basic techniques and recipes, every baker must. Editorial Reviews. About the Author. Nicole Rees-Smith is a professional pastry chef, recipe developer, and food journalist for Chocolatier and Pastry Art Design .
It is native to South America and has been grown in the Andes for over 5, years. It is very hardy, resistant to both cold and drought. Quinoa provides more nutrients than cereal grains; it is high in protein, magnesium, iron, and potassium. Quinoa can be used whole, cooked or soaked, in wheat health breads.
Ground quinoa can be substituted for a small portion of the wheat flour in breads, Wheat and Grain Flours 31 cookies, and muffins. It is usually not used alone since it does not form gluten. It was farmed extensively in Mexico before the Spanish conquest. The seeds are rich in nutrients with a distinctive, slightly spicy flavor.
Amaranth can be used whole, cooked or soaked, in health breads and is also available as a flour. Amaranth has no gluten-forming proteins; it could conceivably be used alone only in waffles, pancakes, or perhaps cookies. Any instance when some gluten formation is needed for structure, however, as in breads and cakes, it should be used in combination with wheat flour. Beyond that, however, yeast and chemical leaveners have nothing in common. They are grouped together in this chapter because their function in baked goods is the same: to make things rise.
YEAST The wonder of risen bread results from the activity of millions of individual yeast cells, yet few people have a good understanding of the yeast products available and how best to utilize them. Yeast is living, yes, but is neither plant nor animal. Yeasts belong to a separate kingdom in taxonomy, the fungus kingdom. There are many, many species of yeast, and they are everywhere.
Undoubtedly, you are covered with some now. How and why did humans harness these unseen microorganisms to make risen bread? Most likely by accident. A piece of dough, presumably to be used for flatbread, may have been left unattended longer than normal by a distracted baker.
Wild yeasts, present in the grain or perhaps the clay bowl, began to multiply and ferment in the dough. Imagine the surprise caused by the lighter texture and interesting flavor of the baked bread—all from a dough 35 36 Understanding Baking that may not have looked much larger before going into the oven! This was a serendipitous discovery, but one that forever changed how we eat. Leavened bread followed the domestication of wheat, and has been in our cooking repertoire for at least 6, years. In Egypt and throughout the Middle East, baking and the brewing of barley ale were closely linked—indeed, it was the same yeast doing the fermenting.
The barm, or ale leaven, could be used to inoculate dough with yeast. This relationship continued into the nineteenth century in England, where yeast left over from making ale could be purchased from local brewers and used at home to make bread. It was not until the second half of the nineteenth century that yeasts were identified by Louis Pasteur as the cause of fermentation. The Carlsburg Laboratories in Denmark were soon able to isolate and develop pure strains of yeast for commercial use, increasing its availability.
A single strain of the species Saccharomyces cerevisiae originally served both brewers and bakers. Later, genetic strains were developed to better suit either brewing or baking. The carbon dioxide bubbles are trapped in the gluten network formed when wheat flour is moistened with water and stirred , making the dough rise as it proofs on the counter and causing the dough to expand further in the heat of the oven.
go The remaining chemicals con- Yeast and Chemical Leaveners 37 tribute to the complex flavor of yeasted bread. In general, a long, slow, cool fermentation makes a tastier bread with better textural and keeping qualities.
If dough is overproofed and the yeast begins to run out of food, the flavor turns from pleasant to acrid. Additionally, the structure of the dough is compromised, resulting in a loaf with poor volume. Yeast breaks down the starch present in flour into sugars, using an enzyme called invertase. Quality flour usually contains enzymes amylases that also break down the carbohydrates in starch to sugars. Bacteria present often work in conjunction with yeast, breaking down starches into simple sugars.
It contains active enzymes that will break down starch, and the malt sugar maltose provides food for the yeast and bacteria. Diastatic malt syrup can be added to bread doughs to improve enzyme activity, add moisture, and contribute sugars and caramel flavors. The powder is preferred in bread doughs, since the syrup makes the dough sticky. Fresh yeast produces the most carbon dioxide gas per cell, giving it superior dough-raising capability. A gram of compressed yeast contains a whopping 25 billion cells.
Sold either solid in blocks or crumbled in bags, fresh yeast is slightly dehydrated about 30 percent but requires no hydration time, unlike active dry yeast. Cakes of yeast can be dissolved with the liquid portion of the dough, and the crumbled form may be incorporated with the dry ingredients. Fresh yeast will not be damaged by cool liquids see below. Naturally, fresh yeast has a shorter shelf life than dry yeast.
To prevent dehydration while in storage, wrap partially used blocks of compressed yeast in waxed paper, then seal in plastic wrap. Remember, at room temperature yeast cells are very active—a block of fresh yeast left on a kitchen work table will quickly run out of food and die. Developed from a strain of Saccharomyces cerevisiae that could withstand dehydration down to 5 percent moisture content , active dry yeast became popular because of its long shelf life.
Essentially dormant until rehydration, a jar or envelope that is hermetically sealed with an inert gas or vacuum-packed will last a year.
After opening, tightly sealed active dry yeast will keep a month at room temperature, but at least two months in the refrigerator. Repeated opening of the jar, which exposes the yeast to warm, humid air, may cause the yeast to lose some of its potency. Adding a small amount of sugar to the warm water, a common practice with older recipes, is unnecessary.
Good cake flour will rely upon the same factors to produce lovely tender cakes that would pro- duce horrible, flat, gummy bread. Other ingredients, such as organic raisins, grapes, and potato water, are unnecessary. Sugar alcohols include sorbitol, mannitol, isomalt, and xylitol. The first step in making malt syrup is to make malt, by steeping the grain in water un- til it sprouts. Ultimately sugar is a chemical desig- nation for specific molecular structures. Though invert sugar can be purchased commercially and in specialty stores, you can make your own by boiling granulated sugar with water about one-third water by weight and adding a small amount of acid, such as citric acid.
Sugar, an immediate source of fuel for yeast, stimulates the yeast to ferment quickly and give off gas bubbles—a surefire way to prove that the yeast is active. The time dry yeast requires for rehydration is called the lag time. Warm water for rehydration not only increases the rate of fermentation but also prevents damage to yeast cells. Cool water causes the cell walls to rupture easily.
This not only kills the yeast but also the damaged cells release glutathione into the dough, which interrupts gluten formation. Active dry yeast produces less gas per cell than any of the other forms of commercial yeast.
Since instant yeast does not require hydration in water, it can be mixed directly with the flour. The exception to this rule is a water-poor dough; to prevent the yeast from competing for moisture with flour, sugar, and starches, mix it first with a little of the warm water called for in the recipe. Instant dry yeast has been available to both professionals and home cooks for some time, but because yeast companies market it differently to each group, there is much confusion.
Quick-Rise and Rapid-Rise, both trademarked brands, are instant active dry yeast. Their brand names have given consumers the impression that these yeasts make dough rise faster than regular active dry yeast. Actually, instant yeast produces more gas per cell, which means less of it is needed to ferment a dough. The bottom line is that fast-rising and instant are the same yeast, as are several brands of bread machine yeast, which contain added dough enhancers.
Instant yeast, or any yeast packaged as rising fast, will work fine for long, slow fermentation so long as the proper amount is used. See the chart on page 40 for how to substitute one type of yeast for another. To compensate for the sluggish performance of yeast in this environment, great amounts of yeast are usually called for in such recipes.
Osmotolerant yeast will not require such bolstering, as they have been specifically selected for lowmoisture, high-sugar doughs. Osmotolerant is a big word, but the concept is very simple: Osmosis is the process of how a solution here, water moves through a semipermeable membrane the cell walls of yeast.
In a moisture-poor dough with added sugar, the yeast must compete with the proteins and starches in the flour and the sugar for what little water is available. This exerts osmotic pressure on the yeast cells, which have trouble maintaining moisture equilibrium. Yeast will multiply as long as good conditions prevail, so even a pinch will leaven several loaves—if you give them time. Though many bakers insist that choice of yeast influences how well a dough performs after being frozen, scientists believe that how the dough is handled is the most important factor.
Ice crystal formation poses the greatest threat to yeast cells, as the asymmetrical hard edges can rupture the cell walls. Obviously, keeping the freezer at a steady temperature will preserve yeast cells, while slight variations could destroy them. All frozen doughs should be thawed gradually, in the refrigerator, before being brought to room temperature.
If you know you will be freezing a batch of dough, keep it as cool as possible and freeze immediately after mixing. If the freezing time is longer than four days, increase the amount of yeast by as much as 10 percent to compensate for possible loss. Where applicable, increase the amount of gluten in the dough to bolster gas retention. This applies to measuring those specific ingredients together, for example. If all the dry ingredients in the recipe are combined, there is no danger, as the flour buffers the yeast.