not a traditional cookbook——it contains only basic recipes intended to illustrate the concepts discussed. I dedicated a separate chapter to bread science so as. Bread Science - Ebook download as PDF File .pdf), Text File .txt) or read book online. making bread. Food science. Activity session 2. Bread science. Key message: Use practical experimentation to investigate and evaluate the working characteristics, functional.

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The Science of Doughs and Bread Quality. Cristina M. Rosell. Department of Food Science, Institute of Agrochemistry and Food Technology, Spanish. Scientific. Bread is one of the oldest pre- pared foods, dating back to Neo- lithic times - 10 years ago! Microbial Sciences Initiative harvard microbiology in action. 51 sex nerd sex tips by Emily Nagoski, Ph.D. This could be anything from 51 sex nerd sex Python Programming: An Introduction to.

It is long, almost half of the book, and relatively dense, but the chapter is full of helpful illustrations and diagrams that help even non-scientific types get what is going on.

I'll admit that I didn't get everything on my first pass through, though a few things, such as the difference between respiration and fermentation, I got better than I ever have before.

I know I will be referring back to this chapter again. The instructional chapters are solid too. The tone is very much like the tone I try to promote on this site anything you bake at home is going to be better than most store bought bread, that making mistakes is part of the learning process, etc. She is a much better baker than I am, and the diagrams and photos in the chapters on shaping and scoring better than anything on this site yet.

Better than those found in most baking books I know. This isn't a cookbook: though there are a couple of formula in the back, it is really about understand the process what is happening inside of your bread and figuring out how your technique can make the most of the good things you want to happen, chemically-speaking, and avoid the things you don't want to happen. It makes a nice complement to all of the baking books you have on your shelf that tell you things like "don't overknead" but don't explain why.

A big chunk of the book is available as a PDF than anyone can download for free. Yeast that is stored too long becomes inactive.

The yeast cells do not die all at onceover time, the yeast will work more and more slowly, until eventually it does not work at all. To determine if yeast is still active, mix equal parts of yeast and flour with some warm water, wait a few minutes, and look for bubbles forming in the flour. Bubbles indicate that your yeast is alive and has started producing gas. Perhaps the simplest ingredient, water deserves much of the credit.

Water starts the chemical reactions that make bread happen by hydrating ingredients, acting as a solvent, and enabling molecules to move about in the dough.

In addition, the water temperature determines the doughs temperature, one of the dough characteristics that the baker attempts to control. The most common question about water in dough concerns the use of tap water. Is it necessary to make bread with bottled water? It depends on the tap water. If it smells and tastes like chemicals, it might give odd flavors to your bread.

In addition, chemicals in the water might interfere with the chemical reactions of the dough.

Filtered or bottled water costs extra, though, and there is a good chance that your tap water will work just fine. Try using each and see if you notice a difference. Salt has many purposes in bread. The most obvious is that it adds flavor. It also acts as a natural preservative by dehydrating bacteria, thus adding shelf-life to bread.

During bread-making, salt slows down the fermentation reactions by dehydrating the yeast and bacteria, allowing the dough to ferment for longer before it must be shaped and baked. The longer fermentation time allows more flavor to develop.

Salt also stabilizes the gluten network, making the gluten stronger. This creates a better dough that resists the building gas pressure and rises more slowly. Technically, salt is an optional ingredient. People on low-salt diets can make bread without it, using other ingredients for flavor and slowing down the fermentation process with cold temperatures. Weighing ingredients requires a scale. Measuring by volume means using measuring cups and teaspoons.

Both ways work, but measuring by weight has important advantages. A certain weight of an ingredient is in effect a certain number of molecules. When dough is mixed, molecules in the ingredients react with each other. By adjusting the weight of each ingredient, the baker controls how much reaction can happen. It seems that volume is analogous to weighta bigger scoop of flour has more molecules. The volume of some ingredients can change, however.

Supplementation of common white bread by coriander leaf powder

Flour can settle or become packed and thus become smaller. Salt crystals come in different sizes; bigger salt crystals have bigger air spaces between them, in effect giving less salt per teaspoon than salt with small crystals. Also, volume measurements are less accuratea teaspoon might be slightly heaping or depressedwhile weight measurements are consistent. Another concern is preferments, discussed in depth in chapter three.

Preferments are dough-like mixtures made a day early and added to bread dough for extra flavor. Their size increases dramatically from the time when they are mixed to the time when they are used. If you try to measure a preferment using volume, how much you use depends on how developed the preferment is. A cup of recently-mixed preferment is densermore flour and waterthan a cup of well-risen preferment that is full of air.

Bread Science

Still, making bread without a scale works. If you measure carefully, cup and teaspoon measurements can be fairly consistent. Preferment amounts can be approximated. Once you are familiar with dough, you will be able to tell if you need to add water or flour by feeling your dough; the actual amount from the recipe loses importance. Recipes in this book are given by weight and volume.

Conversion factors are given in the appendix. Here is the conversion of the basic bread recipe: The resulting recipe in weight and volume is An important note about flour: these numbers are for fluffy, sifted flour.

If you scoop flour up with a measuring cup, it may be packed down and you will use too much flour! Avoid packed-down flour by sifting or by spooning it into your measuring cup one spoonful at a time. For more information on this, see the notes in the appendix.

It is a helpful tool for understanding the basic structure of recipes. A discussion of bakers percent means doing some math. If you are completely averse to reading about math, you can accept the idea of bakers percent on faith and skip this section.

The weights of the yeast and salt are 0.

This means that the ingredients add up to In this book, the more common term weight is used in place of the term mass. Bakers percent may not seem intuitiveperhaps it seems like an affront to accepted mathematics. How can a percentage greater than exist? Think of bakers percent as a useful tool. First of all, percentages are useful for comparing recipes. For example, which bread is better for someone avoiding salt?

One recipe uses four teaspoons of salt, while another only uses two teaspoons; but the four-teaspoon recipe makes a bigger loaf of bread.

A slice from the bigger loaf will not necessarily have more salt than a slice from the smaller loaf. The percentage of salt is important, not the actual amount of salt used. In addition, bread recipes must be flexible. This is because factors can changefor example, the moisture content of the flour or the humidity of the bakery. This is where bakers percent is useful. That would result in unwanted changestoo much salt or yeast, for example. With bakers percent, adjusting recipes is easy.

Compare the original recipe on the left to the new, drier recipe: The waters value has changed, but not the other ingredients values.

Bakers percent provides bakers with a universal measure. Water content or hydration and yeast content also have similar percentages in most recipes.

Controlling these four characteristics is possible at various places throughout the process. Time is key to making good bread for one simple reasonthe longer the dough ferments, the more flavor it will have.

Using a preferment is the first way to increase the fermentation time, by adding a whole extra day to the process. There are many other ways to add time to the process: mixing with colder water to make colder dough, keeping the dough in a colder environment during fermentation, punching the dough during the fermentation step so that it must rise several times, shaping the dough more tightly to allow it to proof more slowly, and proofing the dough in a cold place, even overnight in a refrigerator.

On the other hand, warm temperatures and a single first rise can be used to speed up the process for expediency. This may be necessary in a cold house or if the dough is rising too slowly for undetermined reasons.

New bakers often have trouble with dough rising slowly simply because they are new at kneading and did not knead well enough. Temperatures indirectly affect the flavor of dough by altering the rising time.

University of Pittsburgh School of Medicine

Colder water and a cold environment are two ways to slow down the process. Colder water is used to counteract the heat caused by friction when you use an electric mixer.

Whenever your hands are in the dough, during kneading or shaping, you are imparting heat to the dough. While your dough must be properly kneaded, handle it as little as possible, using brisk, efficient motions. Temperature can also be used to alter rising time, but major changes are made by altering the amount of yeast used. Finally, the temperature of the oven is what bakes the dough into bread. In chapter seven, the importance of the oven temperature in the first ten minutes of baking, when the most expansion occurs, will be discussed.

With each step of the bread-making process, the gas content of the dough determines when the dough is ready to be taken to the next step. For example, preferments should be full of gas when they are used, dough should be full of gas when it is punched down or shaped, and the shaped loaf should be full of gas when it goes into the oven.

Of Bread and Bacteria

Baked too soon not enough gas , it may have a dense center; baked too late too much gas , it may collapse. The baker repeatedly removes gas from dough and allows it to reform. Instructions for proper gas removal during shaping are given in chapter six. A poor job removing gas during shaping results in bread with gaping holes inside.

When the dough goes into the oven, it should have an even distribution of gas inside. Sometimes dough seems overly gassyit rises too fast and becomes weak and hard to work with.

The main control on gas content is how much yeast is in the recipe and how active the preferment is when it is used. Problems with persistently gassy dough are solved by using less yeast.

Temperature also controls gas content. Extreme high temperatures can cause dough to rise too fast, quickly resulting in an overly gassy dough. Dough with too much gas is sloppy to work with and forms messy bread. Dough strength is the characteristic that the baker has the most chances to control, beginning with what type of flour i.

Strength is subsequently controlled by how long the dough is mixed, how often and how tightly it is folded, how well it is shaped, and how it is scored before it enters the oven. Dough that is too weak or too strong will not rise properly. Weak dough will not retain gas well, while overly strong dough will resist gas pressure and not allow dough to rise.

In addition, controlling the strength of the dough is important for making an aesthetically pleasing loaf of bread. Dough that is too weak or too strong will be hard to shape well. Once shaped, uneven strength causes uneven expansionweaker spots in the loaf will rise more, ripping during the rapid expansion in the oven.

The internal structure will be uneven. The dough characteristics affected by each step of the bread-making process are summarized below. Mixing a preferment optional.

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Flour, water, and yeast or sourdough starter can be mixed the day before the dough is made. This preferment rises overnight as fermentation begins. Mixing the dough. Flour, water, a rising agent yeast, preferment, or both , and salt are incorporated together. There is an optional rest period, and then the dough is kneaded. Fermentation rising. The covered dough is left to rise. Punch and fold. The dough is punched to remove gas. It is folded to add strength.

The dough rises again. The dough is cut into pieces if necessary, gas is removed, and it is shaped into boules, baguettes, batards, or other shapes. Proofing rising. The shaped dough is covered and left to relax soften and rise. It fills with gas one last time. When it is full of gas, the dough is put into the oven, where it expands and solidifies, turning into bread. After the bread is baked, it is placed on a rack to let it cool properly.

You are ready to set off on your bread-making adventure! Remember that this can be a lot of fun. Your dough might not be perfect the first time you make it, but if it were perfect every time, you would never learn. Keep notes of how it turns out and make adjustments for next time. To make really great bread, you cannot just follow steps. You have to pay attention to the dough, take care of it, and use it when the time is right.

The good baker waits for the dough to be ready and then acts before it is too late. The following chapter delves into the science occurring in dough throughout the entire process of bread-making. Chapters three through seven split the process into steps, not only describing how to do a step of the process, but also pointing out the little things to watch for to improve your bread.Poor flours might have more protein overall.

Osborne observed that proteins are sensitive in solution—minor differences in solubility cannot be used to characterize an individual type of protein. Through a pre-examination, the maximum and minimum ranges of ramie powder and water were determined to be 1.

The percentage of salt is important.

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