Bread

Table of Contents

• Updated
• Bread
  • Grain
  • Leaven, Cultivated Yeast
  • Industrial Bread Production
• Resources
  • Skill, knowledge, Practice
  • Sources
  • The California Writer
    • Who
    • Bread Bible
    • Bread Machine Cookbook
  • The Artisan
    • Who
  • The Baking Teacher/Chemist
    • Who
  • The Sourdough Professor
    • Who
    • Sourdough Culture
  • Videos
• Ingredients
  • Flour Milling Standards
  • Rising Agents
  • Salt
  • Baker’s Percentage
• Mixing and Kneading
  • Pre-Modern
  • Machines

Updated

I wrote and published this in 2021. After major changes I republished in 2025.

Bread

Grain

The history of baking before 19th and 20th centuries has been uncovered by archeological studies and historical research. As the first hominids and homo sapiens evolved, they ate seeds including the seeds of grasses. Hom0 sapiens began to grow certain grasses, harvest them, and dry the seeds. Several civilizations cultivated grasses (notably wheat, rice, corn) and some other plants (e.g. potatoes, yams, squash in the Americas) for starch, and legumes for more nutrition. Wheat, and other grains, became food sources in parts of the world and the civilizations that formed there.

Human beings began to crush the seeds, mix dried crushed seeds and water into a mush or paste, use fire to cook the mush Eventually human beings discovered that wet mush made with fruit or grain could become a drinkable substance containing alcohol or something gassy and that gassy mush, when heated, became somewhat sweet and tasty. Also, human beings made machines to crush the seeds into meal and flour.

In the processes of harvesting, drying, grinding and milling grain the starches in the endosperm are separated and preserved. Bread is made by mixing flour and water into a dough, kneading the dough, and baking the dough:

Bread is a combination of flour and water that has been baked. Over the years, its production has become increasingly more complex. Bread is a staple food in many countries, with cultural significance. With common sayings such as “the bread winner,” it has become one of the most important parts of the world’s diet.

Bakerpedia.com, Specialties, Bread

When the small particles of a milled flour are mixed with water, starches dissolve. The starches are rearranged by mixing flour with water, until the wet flour became a mass of dough. Grain meal and flour are the product of grinding and milling cereal (grain). Grain and flour are NOVA class 1 unprocessed or minimally processed foods.

Dough became bread when it was baked – heated by warm air or contact with a heated metal or ceramic surface. An unleavened dough may be baked into flap of flatbread or a cracker. Unleavened bread may have some natural yeast in the ground grain, which only has a few minutes to act, after the grain is hydrated.

In the middle East, Europe and America, for centuries, most bread has been made with a rising agent, also called a “leaven”. The yeast Saccharomyces cerevisiae, known as vintner’s yeast, brewer’s yeast and baker’s yeast, was scientifically identified as source of fermentation in the middle of the 19th century. The industrial production of baker’s yeast (and chemical agents like sodium bicarbonate) began the 19th century. Until leavens became commodities, leavening was a method learned by trial and error and taught by demonstration, word of mouth, apprenticeship and practice.

A grain with the precursor proteins form strands of gluten. Wheat has the precursor proteins that bond as gluten. Other grains have less. Kneading dough has been believed to alter the gluten into a web that traps the gases released as a leaven interacts with the starches or water in dough. As leavened dough is baked, it rises until the microbes have died or chemical reactions have stopped. A leavened dough could rise into a shape that would become a bun roll, or a loaf. The outside of the dough became the crust. The inside became crumb.

Leaven, Cultivated Yeast

Many 20th century and later resources discuss milling and refining flour and the process of baking with refined flour and pure yeast. Leaven was discovered long before bakers and scientists understood it. A living microbiome or culture was used as the natural leavening agent to raise bread dough long before scientists understood yeast and bacteria or made the cultivation of yeast conceivable. Bakers used natural leavens wherever ground wheat or flour was available, for 6,000 years. Dr. Pallant’s Sourdough Culture (noted below) discussed some archeology and ancient history. It also discussed the success of Austrian industry in cultivating baker’s yeast, producing wet yeast cakes, and bringing the innovations to the USA, which I will mention again in more detail.

For most of the 20th century, the use of industrially grown baker’s yeast dominated the business of baking. The yeast industry developed processes for breeding, feeding, harvesting, compressing and transporting yeast and developed products for people who were able and willing to bake bread instead of buying it. In the 20th century, the yeast producers developed dry yeast and started to sell dry yeast.

There were bakers in France, parts of the USA and elsewhere in the world who continued to use traditional leaven. In France, bakers began to use both cultivated yeast and traditional leaven. Traditional leaven would be used to make pre-ferments to affect flavor and cultivated yeast to get dough to rise faster and more predictably. “Artisinal” bakers elsewhere paid attention. Traditional leaven was also practiced in the sourdough traditions in the USA

Prof. Pallant discussed the way that natural leaven has been presented in the myths about sourdough and about the miners of the San Francisco and Klondike gold rushes in the Western USA and Alaska. Some bakers in San Francisco promoted their their product as authentic sourdough on the basis that there is something special about a small area of northern California.and used the California Gold Rush myth as a promotional story. Prof. Pallant praises modern bakers and authors including Peter Reinhart (below) and Chad Robertson, (author of Tartine Bread (2010); a founder of the eponymous bakery). Prof. Pallant noted that the San Francisco myth has been deflated by the discoveries that the production of lactic acid by Lactobacilli favours the success of several kinds “wild” bread yeast, and of the discovery of several kinds of Lactobacillus by analysis of the genomes. He suggests that the growth of a microbial culture that can leaven (and affect the flavor) bread dough is a common occurrence when flour and water are infected by Lactobacilli and “wild” yeast.

Industrial Bread Production

Most people purchase bread made by industrial bakers from grocery stores. Some shop at bakeries.

Unpackaged bread is a NOVA class 3 processed food, if the bread as baked under these conditions:

Processes include various preservation or cooking methods, and, in the case of breads and cheese, non-alcoholic fermentation. Most processed foods have two or three ingredients, and are recognizable as modified versions of Group 1 foods. They are edible by themselves or, more usually, in combination with other foods. The purpose of processing here is to increase the durability of Group 1 foods, or to modify or enhance their sensory qualities.

https://world.openfoodfacts.org/nova

Packaged industrially baked bread is a NOVA class 4 ultraprocessed food due to the additives and the processing of ingredients:

Additives in ultra-processed foods include some also used in processed foods, such as preservatives, antioxidants and stabilizers. Classes of additives found only in ultra-processed products include those used to imitate or enhance the sensory qualities of foods or to disguise unpalatable aspects of the final product. These additives include dyes and other colours, colour stabilizers; flavours, flavour enhancers, non-sugar sweeteners; and processing aids such as carbonating, firming, bulking and anti-bulking, de-foaming, anti-caking and glazing agents, emulsifiers, sequestrants and humectants.

A multitude of sequences of processes is used to combine the usually many ingredients and to create the final product (hence ‘ultra-processed’). The processes include several with no domestic equivalents, such as hydrogenation and hydrolysation, extrusion and moulding, and pre-processing for frying.

The overall purpose of ultra-processing is to create branded, convenient (durable, ready to consume), attractive (hyper-palatable) and highly profitable (low-cost ingredients) food products designed to displace all other food groups. Ultra-processed food products are usually packaged attractively and marketed intensively.

https://world.openfoodfacts.org/nova

Many people have kitchens and ovens and could bake bread if they purchased flour and other ingredients and had time, and knowledge of technique and science. It is a specialized activity. Bread baking may have been a part of the education of students in home economics courses. Persons who work in bakeries may have taken courses in vocational educational institutions or learned from experienced bakers in work experience.

Resources

Skill, knowledge, Practice

Grinding grain, milling flour and baking bread were skills taught by demonstration; bakers learned by doing for centuries. Emily Buehler wrote:

Reading about bread will not be enough … the only way to know dough and bread is to have your hands in it – practice. … “failures” are just opportunities to learn. … messed up bread often still tastes good!”

….

Good bread is not the result of one brilliant mind; it came about by trial and error, over the centuries … by ordinary people; it does not require special talents or an advanced degree. Relearning the process from the beginning is surprisingly simple. … making bread “by hand” might seem to be a lost art, but it remains accessible to anyone …

Emily Buehler, Bread Science, (2006, 2021. Two Blue Books, Hillsborough N.C., USA)

Sources

I will mention some sources, their publications. I will start with a “who” section for several sources.

Much of the information published in books or electronic media including the internet, written in or since the late 20th century by agricultural sources, millers, bakers, restaurateurs, journalists and other writers assumes an understanding of milled flour, clean water, energy for machinery and ovens, cultivated yeast, science and technology that happened in the 19th and 20th centuries.

The California Writer

Who

In The Bread Bible Beth Hensperger mentioned her experience baking in a restaurant kitchen, holding workshops, teaching and writing in the introductory chapter, “The Art and Science of Good Baking”. She became a writer on bread. She was a journalist and columnist with a following among food enthusiasts and aspiring home bakers. She wrote a couple of the books were titled as the cookbooks of the retail outlet Williams-Sonoma. She was a Her list of works in Goodreads contains of 30 works in before 2011. Her biography on the Amazon Store said:

Beth Hensperger, a New Jersey-born who now considers herself a California native, has been educating, writing, and demo-lecturing about the art of baking bread and cooking for thirty years. …

Hensperger’s writing career began when she was chosen as the guest cooking instructor for the March 1985 issue of Bon Appétit. Now she is the author of over twenty cookbooks, including the best-selling Not Your Mother’s Slow Cooker Cookbook series, which includes Not Your Mother’s Recipes for Entertaining, Not Your Mother’s Family Favorites, Not Your Mother’s Weeknight Suppers, and NYMSC Recipes for Two along with the blockbuster first volume, Not Your Mother’s Slow Cooker Cookbook. Also from The Harvard Common Press are The Bread Lover’s Bread Machine Cookbook, The Ultimate Rice Cooker Cookbook, and The Best Quick Breads. She is also the author of The Bread Bible, winner of the 2000 James Beard Book Award in Baking, and nominated twice for an IACP Cookbook Award.

Hensperger wrote a food column, “Baking with the Seasons,” for the San Jose Mercury News (which was nominated for a James Beard Award in newspaper journalism) for over 12 years until the newspaper downsized.

….

https://www.amazon.com/stores/author/B000APB838/about

There is a note by “Darcie” March 25, 2021 in the blog section of the otherwise paywalled Eat Your Books web site:

We learned through cookbook author Rick Rodgers that acclaimed San Francisco Bay Area-based food writer, cooking instructor, and bread baking maven Beth Hensperger has died after years of declining health. An editor who worked with Hensperger confirmed her passing although there has not yet been an official announcement.

https://www.eatyourbooks.com/blog/2021/03/25/baking-maven-beth-hensperger-has-died

Beth Hensperger had a web site with many recipes, at one time. The web site was gone by 2021; her domain was high-jacked by web squatters. Information about her life and career are drowned in returns in searches by results for pages published for online booksellers selling copies of her books .

Bread Bible

The Bread Bible: Beth Hensperger’s 300 Favourite Recipes, (1999) Chronicle Books, San Francisco was published by the independent publisher. Hensperger was then known as columnist and as the author of 5 books. The Bread Bible earned the James Beard Foundation award in 2000 in the Baking & Dessert category. It has a cover photograph and some photographs of dough and bread products. It was published as an e-book, apparently in 2013, when it appeared in Amazon Kindle format. As of 2025 is for sale online as an e-book 0r a used book.

The Bread Bible was criticized by a reviewer at the Fresh Loaf site: https://www.thefreshloaf.com/bookreviews/henspergerbible.

Beth Hensperger’s The Bread Bible is lengthy, but is neither authoritative or complete. The subtitle, “Beth Hensberger’s 300 Favorite Recipes” really gets to what this book is: a large collection of good recipes.

January 25, 2005 https://www.thefreshloaf.com/bookreviews/henspergerbible

The Bread Bible did not discuss commercial baking, the methods used by commercial bakeries and the methods of professional bakers – e.g. framing recipes according to Bakers’ percentage – or the food science of baking as understood by other writers. The Bread Bible was directed at the perception that home bakers wanted information though form of recipes being shared, presented in the cookbook format using measurement by volume (e.g. cups, tablespoons, teaspoons and fractions of those standards). The Bread Bible had recipes

• for home bakers who baked in ovens;
• that mainly used ingredients available to retail customers in stores in large American urban centers.

The book has 300 recipes, more than any one baker would ever try. An ambitious person might buy the book as a resource. One problem with a recipe books is that they may respond to trends and fads. Another is that cooking technology changes. Even in ingredients change. Active dry yeast was the preferred way of leavening bread made with wheat flour in the second half of the 20th century. Active yeast was improved near the end of the 20th century when the processes for drying yeast and packaging it changed. Yeast processor retained familiar ways of packaging the produce – foil sachets and small jars, but filled the packages with more live yeast. Hensperger used “old” active dry yeast measurements in her recipes, stating the a .5 ounce packet was a “scant tablespoon” of Active dry yeast by volume. A .5 ounce (8 gram) packet, for several years before 2025, has been only 2¼ teaspoons. This requires a baker to make an adjustment when using active dry yeast, or to make a calculation to convert if using other kinds of dry yeast.

The epigraph, a quotation from the novel Reckless Appetites (1993):

Bread baking has somehow taken on a mysterious quality, making it seem an intimidating act for many people. The secret to making good bread is that there is no secret. Let your imagination help you break any rules you imagine exist to daunt you.

Reckless Appetites, Ecco Press, 1993

Later in the opening chapter she cited books that had influenced her: the Tassajara Bread Book (1970), A World of Breads (1966).

However, on the same page as the epigraph, Hensperger noted:

Successful baking combines the elements of a balanced recipe, proper equipment, and good ingredients with skilled hands and a dash of imagination.”

Unlike many other books, The Bread Bible says something about how dough it mixed and bread is baked in the chapters: “The Baking Process” and “The Elements of a Loaf: Ingredients”. She wrote with the knowledge of a person with formal vocational training who had working in bakeries and had talked to persons who baked bread for sale and made bread for themselves. The information reflects the common sense of late 20th century bakers, based on centuries of baking.

Her discussion of Yeast in the “Ingredients” chapter goes into some details – e.g. how to acquire compressed wet yeast cakes and bricks. She is vague on history of the cultivation and processing of yeast, but makes the point that yeast are microscopic living things.

She mainly discusses active dry yeast (without mentioning it was an invention that was marketed in the 1940s). She emphasizes that active dry yeast has to be activated by hydration and nourishment with sugar, and that it is perishable. She discusses how active dry yeast was presented on the baking supplies shelves of grocery stores. It was and is sold in strips of 3 foil half ounce (8 gram) pouches and glass jars holding 4 oz. (113 g.) or 8 oz. (227 g.).

She discussed other processed dry yeast products that could be added dry without being proofed. She said instant, Quick-rise and Bread Machine were interchangeable with other dry yeasts. Indeed, all are baker’s yeast that consume starch and pump out gas.

She said instant yeast, which she called a European strain, had started to be available at the end of ’90s. She was clearly referring to the LeSaffre products sold in the USA by King Arthur Flour. Her discussion lacked information summarized (in 2022) on the King Arthur site:

Instant yeast: … used in my kitchen since King Arthur introduced it to home bakers over 25 years ago. Specifically, … SAF Red instant yeast (or SAF Gold for sweet breads). …

….

… Originally, the classic active dry yeast manufacturing process dried live yeast cells quickly, at a high temperature. The result? Only about 30% of the cells survived. Dead cells “cocooned” around the live ones, making it necessary to “proof” the yeast — dissolve it in warm water — before using. 

These days, active dry yeast is manufactured using a much gentler process, resulting in many more live cells. Thus, it’s no longer necessary to dissolve active dry yeast in warm water before using — feel free to mix it with the dry ingredients, just as you do instant yeast.

Active dry yeast, compared to instant yeast, is considered more “moderate.” It gets going more slowly, but eventually catches up to instant — think of the tortoise and the hare. Many bread-bakers appreciate the longer rise times active dry yeast encourages; it’s during fermentation of its dough that bread develops flavor.

….

Instant yeast … is manufactured to a smaller granule size than active dry. Thus, with more surface area exposed to the liquid in a recipe, it dissolves more quickly, and gets going faster than active dry. While you can proof it if you like, it’s not necessary; like active dry yeast, simply mixing it into your bread dough along with the rest of the dry ingredients works just fine.

P.J. Hamel, August 15, 2022, “Active dry vs. instant yeast … “

Hensperger noted instant yeast was dried differently than active dry. She said it was coated in ascorbic acid and sugar.

She said that bread machine yeast was dry like instant yeast but coated, by the manufacturer who discussed it with her, with ascorbic acid and “a flour buffer”.

She said that Quick-Rise yeast was grown, and dried differently than active dry, and treated with conditions including emulsifiers and anti-oxidants. She said the particles were more finely ground. Fleischmann’s still uses that name for that product. Competitors use different names for similar products. Fleischmann’s may have a trade mark or some protection for the name.

The selling points for this product were that it could be used dry, and that it was faster than active dry yeast. It is just yeast, but a given volume – say a tablespoon – has more live yeast cells than the same volume of active dry. It was faster because it the yeast multiplied and made gas sooner.

The Bread Bible discussed mixing dough and kneading dough be hand in electric mixers and food processors. It had a chapter on bread machines.

Bread Machine Cookbook

The Bread Lover’s Bread Machine Cookbook (“BLBMC“) was published by the Harvard Common Press in 2000. I have had a copy for over a decade. I discussed the 2000 edition in this blog in a post first published in 2020, edited extensively in 2025.

The 2000 edition has good sections on ingredients, dough and baking in general. It explained how bread machines could consolidate mixing, kneading, fermentation and baking reasonably good bread in a pan, in a small device. The book had several problems.

In 2023 and 2024 Quarto (a company related to Harvard Common) published two books based on the BLBMC. Both were placed with Walmart and Target stores, and on Amazon, where a book complements the sale of bread machines. Both were sold to libraries and educational web sites and services. The new books:

• 2023 – Bread machine baking for beginners : effortless perfect bread (“Beginners“), an “affordable abridged edition” of the BLBMC; and
• 2024 – a “newly revised and expanded” edition of the BLBMC.

The posthumous editions are not new. They do not overcome the problems of the 2000 edition. They extended the life of this book as a profitable title for the publisher, and perhaps for Hensperger’s estate.

The Artisan

Who

Peter Reinhart has been a baker, entrepreneur, competitive baker, advocate of collaboration among bakers, educator and consultant. He discussed his life in a chapter of Peter Reinhart’s Whole Grain Breads (2007). He baked while a member of troupe of performers in the 1970s, and in a group operating a whole food cafe in Boston. He became a member of a New Religious Movement called the Order of MANS, a Christian group organized like a Catholic religious order. He spent several years working in social service. He was one of the founders of Brother Juniper’s Cafe in Sonoma in 1986. Brother Juniper was named for Junípero Serra, the 18th century Spanish missionary beatified by the Roman Catholic Church in 1988. The objections of Americans descended from Indigenous people to the Spanish catholic missions in California in the 17th century did not influence 20th century entrepreneurs and consumers.

Peter Reinhart was an independent baker in California. Many of them competed against industrial bakeries (and against the independent bakeries that promoted “California” sourdough). He left Brother Juniper’s in 1993, and became an educator and promoter. He joined the Bread Baker’s Guild of America, and attended Raymond Calvel’s baking workshops in America in the 1990s. The James Beard Foundation’s award to him in 1995 for a bread baking competition gave him time in France to study the methods of highly regarded bakeries, which had evolved from Calvel’s work. He suggested that the encounters of Americans with French bread influenced a movement for artisanal baking in America. He later said, referring to the 1990s:

The word artisan lost lost its full impact the day that Safeway began using the brand name Artisan to describe their store-baked loaves.”

Peter Reinhart’s Whole Grain Breads, (2007)

His first book was Brother Juniper’s Bread Book: Slow Rise As Method and Metaphor (1991). He books in the 1990s and 2000s included:

• Crust and Crumb: Master Formulas for Serious Bread Bakers (1998, 2006);
• The Bread Baker’s Apprentice: Mastering the Art of Extraordinary Bread (2001);
• American Pie: My Search for the Perfect Pizza (2003);
• Peter Reinhart’s Whole Grain Breads: New Techniques, Extraordinary Flavor (2007);
• Peter Reinhart’s Artisan Breads Every Day (2009)

The Baking Teacher/Chemist

Who

Emily Jane Buehler worked in a coop bakery, and later in Weaver Street Bakery in Carrboro, North Carolina. She met Peter Reinhart at a bread even in Asheville in 2006, and is mentioned in his 2007 book. She taught community courses before she wrote Bread Science which she published:

• in print using the publishing firm name Two Blue Books in 2006 and
• as an e-book in 2014, republished in 2021 in a 2nd edition.

She researched the science of grain, milling, dough and baking in the professional journal collections of the University of North Carolina, Chapel Hill.

She presents the science of gluten and fermentation, the practical technique of handling dough, an explanation of bakers’ percentage, and a discussion of the techniques of making and using pre-ferments (also known as sponges and starters). These techniques and stages affect fermentation, which affects the rising of the dough and the flavour of the bread. They are used in making sourdough bread, and less common – actually rare – in making yeasted bread. Chemically leavened bread rises in proportion to the amount of chemical leavener, water, starch and heat.

The Sourdough Professor

Who

Eric Pallant, professor of Environmental Science & Sustainability at Allegheny College in Meadville, Pennsylvania, USA . He is a practitioner of sourdough baking.

Dr. Pallant was introduced to sourdough when he was given a sourdough starter when he was a new assistant professor in 1988. Sourdough Culture (2021) is organized around his investigation of the story that the starter given to him was descended from a starter given to a backpacker hiking near Cripple Creek, Colorado in the 1970s, said to have been started during the 1893 gold rush near Telluride, was propagated and came into his possession a century later. Dr. Pallant has written about sourdough baking on the Web at Maurizi0 Leo’s The Perfect Loaf site. (Pallant’s posts and essays on that site are indexed.) The site has been published since 2012. Maurizi0 Leo has published a book of the same name in 2022 and has recorded several videos on a YouTube channel of the same name.

Sourdough Culture

Sourdough Culture (2021) addressed the history of baking in sections on archeology, the wheat trade in the Roman Empire, and the ovens and bread of Pompei. I found this book almost by accident, as I was looking for another book in the stacks at a branch of my local library system in 2025.

Videos

YouTube videos that demonstrate technique and what dough looks like as it is kneaded. Search tools drive users to sift through many search returns. Lesaffre’s Red Star brand has some useful videos on its channel:

• How to make yeast bread using the hand kneading method (2014);
• How to Make YEAST BREAD Using a STAND MIXER;
• How to Knead Yeast Bread Dough by Hand.

Ingredients

Flour Milling Standards

Whole wheat and bread flour weigh the same amount per unit of volume. Whole wheat flour, pastry flour and American all-purpose flour have proteins to make gluten but not quite enough. Bread flour milled to US and European standards (and Canadian All-Purpose) at 12.5% has more of the proteins that bond to form gluten. Gliadin and glutenin are insoluble proteins in grain and in flour. These proteins are in wheat flour, and an smaller amounts in flour made with other cereals. The protein can be extracted by milling wheat flour and processed as vital wheat gluten (“VWG”) powder, and mixed into bread dough:

Consisting of mainly gliadin and glutenin, wheat gluten is unique among cereal proteins based on its ability to form a cohesive and viscoelastic mass. This rheological property makes it a dynamic material that is able to grow and keep the gasses within the dough during extended fermentation periods. The viscoelastic nature also provides the oven spring (increase in height due to the expansion of gasses) that we see in the oven.

….

The addition of VWG generally increases the dough mixing time and fermentation time. As more protein solids are added, more water is needed for complete flour hydration.

Due to its cohesive and viscoelastic properties, its main function is a dough strengthener. It is also a film former, binder, texturizer, fat emulsifying agent, processing aid, stabilizer, water absorption and retention agent, thermosetting agent, and a flavor and color binder.

Vital gluten can absorb almost twice its weight in water (140–180% water). The quality of dry vital gluten is estimated with the Brabender farinograph or Chopin Alveograph. The breadmaking quality of VWG is also assessed through standardized baking tests.

Bakerpedia.com, Articles, Vital Wheat Gluten

When water is added to flour, these proteins bond into strands and sheets of gluten “a composite of storage proteins … found in wheat, barley, rye, oats, related species and hybrids … “. Gluten gives elasticity to dough, helping it keep its shape and often gives the final product a chewy texture.  Gluten relaxes in time which lets the dough flow and rise.

Gluten forms when water is added to wheat flour. Bakers knead dough, stretching and folding it on itself, repeating the motion for several minutes. This structures the gluten. A baker can pause after mixing or start kneading, or pause during kneading. Kneading structures or pulls the gluten into a network of micro balloons. The dough should be viscous (tenacious and elastic) to hold together, but extensible to stretch, and to flow. A professional baker will probably use a mechanical mixer; many home bakers may have one. A mechanical mixer or stand mixer uses mixing arms, a paddle or a spiral dough hook in a circular or elleptical motion. A mixer has a range of speeds.  The baker uses a slow speed to mix the ingredients and a higher speed to knead.

Rising Agents

Modern bakers, depending on location, culture, and resources still produce unleavened or partly leavened flat bread.

A rising agent creates bubbles in the dough that create the bubbled texture of the “crumb” inside the crust of the baked loaf. Rising is caused by the infection of the wet flour by yeast. The yeast Saccharomyces cerevisiae, known as brewer’s yeast or baker’s yeast, causes fermentation of fruit and grain, which makes it possible to make wine, beer (and spirits) and to leaven dough to bake bread.

Before the mass production of baker’s yeast, other yeasts and bacteria could infect a dough. Bacteria and yeast are “wild” organisms in the air or on the ingredients. The traditional method was based on natural infection. Some bacteria could cause interesting tastes, which were not always well received by consumers and bakers.

Some bakers took yeasty foam over the top of ale being fermented as the yeast consumed the starches in the brewed liquid, which brewers called the “wort”. Bakers began to cultivate yeast at the end of the 18th century. The industrial production of yeast for flour and bread meal began in the 19th century. Industrial bakeries mainly use yeast leaven evenly, quickly and efficiently. In the late 18th century, bakers, chemists and biologists in the Austria-Hungarian empire found a way of growing cultures of pure baker’s yeast. Pure yeast was skimmed, compressed into cakes of wet yeast. This process was adapted and industrialized. The Austrian Fleischmann family industrialized the process in the USA in the late 19th century. 20th century changes in yeast production:

During World War II, Fleischmann’s developed a granulated active dry yeast for the United States armed forces, which did not require refrigeration and had a longer shelf-life and better temperature tolerance than fresh yeast; … . The company created yeast that would rise twice as fast, cutting down on baking time.

In 1973, Lesaffre created instant yeast (also called “quick rise” or “fast acting” yeast), which has gained considerable use and market share at the expense of both fresh and active dry yeast in their various applications. Instant yeast differs from active dry yeast in several ways: Instant yeast rises faster than active dry yeast; instant yeast can be directly added to the dry ingredients, whereas active dry yeast should be mixed with liquid (water, milk or beer) and proofed before mixing; instant yeast has a lower moisture content; and instant yeast is formed of smaller granules.

https://en.wikipedia.org/wiki/Baker%27s_yeast

Cultivated processed yeast became the main leavening agent for bread baking. natural leaven was still used to create pre-ferments – e.g. levains, sponges, biga and pâte fermentée (old dough) used in conjunction with baker’s yeast. The traditional method of rising dough have been perpetuated by artisinal bakers and bakers who bake sourdough.

Baker’s yeast and other yeasts consume some of the starches – it ferments, creating gas, which is trapped in gluten in the dough, which makes the bread rise, after the dough has been kneaded. Bakerpedia explains, condensing a number of complex biochemical processes:

When yeasted dough ferments [it] rises and increases in volume, and flavor is developed.  Yeast converts starch in flour into sugar, carbon dioxide and ethyl alcohol. CO2 gas is trapped by gluten proteins in the flour which causes dough to rise. Fermentation results in a light and airy crumb.

Bakerpedia.com, Vital Wheat Gluten

The propagation of yeast and the fermentation of dough accelerate. The dough rises in 2 or 3 stages: bulk fermentation, intermediate, and final proof. Dough is folded or knocked down to release gas at the end of the bulk fermentation, and folded when the loaf is shaped. The dough rises again in the baking pan and springs when yeast warms up after the pan goes in the hot oven, before the heat kills the yeast.

Commercial bakers also use chemical leaven for some bread: baking powder and baking soda for corn bread, soda bread, cakes and other baking.  Baking powder is baking soda mixed with cream of tartar. Kraft Foods Magic Baking Powder does not provide Food Facts on the labels of small jars in Canada.  The published information is that 1 tsp. of baking powder has 300 mg. of sodium.  Substitutions for baking powder involve 1/4 tsp of baking soda plus some acid (e.g. vinegar, cream of tartar) for each tsp baking powder. Baking soda is sodium bicarbonate.  It has 1,259 mg. of sodium per teaspoon. A functional substitution for baking soda and baking powder: potassium bicarbonate, the key ingredient of Featherweight – not an widely available (i.e. in grocery stores) product.  It is available as a supplement but has a list of side effects and do not use if taking medication warnings. Please Don’t Pass the Salt has recipes for quick breads, and suggestions on low sodium “baking mixes”. “Natural” products that that might trap CO₂. Some recipes for some baked goods suggest that some natural products may trap CO₂ e.g. whipped egg whites.

Salt

Mark Kurlansky’s excellent book Salt: a World History (2002) tells of the use of salt to bake bread in Egypt (3,000 BCE),  The production of salt may have started about 8,000 years ago.

Salt is part of the process for most bread sold by grocery stores and bakeries large and small. Bread is high in sodium, as an effect of the baking process. Salt is a standard and necessary ingredient in most formulas and recipes. A few bread styles, such as Tuscan bread, are made without salt. Salt:

• has a chemical effect on the taste buds (Lallamand Baking Update, Volume 2, No. 6);
• affects the development of gluten. It affects chemical bonds in amino acids in proteins in flour that has been exposed to mixed with water. It makes the gluten more tenacious and elastic;
• controls yeast which affects fermentation. Fermentation affects flavour but it also affects rise, which affects the size of the loaf and the production line.

The right ratio of flour to salt and yeast, among other things, means a loaf that will rise on time, and not overproof or balloon. The loaf should spring in the oven and crown to form a dome.

Salt can be reduced, with a reduction in the amount of yeast. Some books and internet pages eliminating salt but incorrectly list the same amount of yeast that would be used if there was salt in the recipe! This will may bake or collapse. In a bread machine, the dough will balloon and may or collapse before it overflows the pan.

Every reduction in salt has to be balanced with a reduction of yeast. Please Don’t Pass the Salt has recipes for yeasted breads and a note on the general adjustment for yeasted bread recipes. Artisan bread baking writers suggest that adjusting the salt in formulas leads to unsatisfactory results  – e.g. Peter Reinhart, Artisan Bread Every Day (Ten Speed Press, 2009) at p. 15 suggests not reducing by more than 10%.  Salt and kneading affect gluten.  It is easy to get to reduce salt to 50% and 33% reduce the salt added to the mixing machine when dough is mixed. These reductions are not usually made by industrial bakers. Changes in salt will affect the gluten, affecting texture, and storage of bread, as well as fermentation and taste.

The most precise way of measuring is by weight. An accepted rule of thumb is reducing proportionately by weight to maintain the same percentage.

Goal	Reduction	Use Salt	Use Yeast
50%	50%	50%	50%
33%	67%	33%	33%

Baker’s Percentage

Professional bakers and some home bakers express ingredient lists or recipes in baker’s percentage (B%) to use consistent processes to manufacture a consistent product. Professional bakers may use 2 pounds of salt and .77 pound of instant yeast per 100 pounds of flour.  The B% for salt is 2%; the B% for instant yeast with most loaves made with bread flour is .7% but B% can vary. It may be over 1%. A yeast B% of .7% in one loaf works out to .3 ounces = 8.5 grams = 8,500 mg. salt per 3 cups (15 ounces) of flour.  A normal loaf of bread weighing 1 ½ lbs. (a bread machine medium loaf) has 3,400 milligrams of sodium per loaf – several hundred milligrams per slice or serving. Home bakers work with small amounts of salt and yeast. Bread machines use very small amounts for single loaves.

Measurement of salt and yeast by weight is desirable for home bakers and bread machine bakers. Few home bakers have scales precise enough.

Conversion? The majority of recipes refer to standard ground table salt. For table salt: 1 tsp = 5.7 grams or .20 oz.  Some fine crystal table salt on the market in the US weighs 7 grams per teaspoon.  I do not pay attention to this information unless the recipe I am referring to has used a coarse or fine salt:

• America’s Test Kitchen/Cooks Illustrated The Science of Good Cooking (2012) lists several brands of kosher salt and sea salt and compares them to table salt, suggesting that Morton’s brand is the standard for table salt at 1 tsp = 7.15 g.
• Peter Reinhart, The Bread Baker’s Apprentice (Ten Speed Press, 2001) says on p. 28 that 1 tsp of table salt = .25 oz which converts to 7 grams. 

The size of the salt crystals affects solubility, which can affect the distribution of salt in the dough, and effect of salt on yeast.  However  a gram of kosher salt works as well as a gram of table salt for baking bread.

Some sources say for instant yeast: 1 tsp  = 3.15 grams. Peter Reinhart, The Bread Baker’s Apprentice (Ten Speed Press, 2001) says on p. 28 that 1 tsp instant yeast = .11 oz which converts to 3.12 grams. It is hard for home user to verify the weight of a teaspoon of instant yeast with home tools and methods. Instant yeast may vary slightly depending on the manufacturer, time and how the yeast has been stored and handled.

Mixing and Kneading

Pre-Modern

The Babylonians, the Egyptians and the Romans had mechanical kneading drives driven by human or animal labour. Europeans used human labour to knead bread until the energy transformations and innovations of the 18th and 19th centuries

Machines

Modern professional bakers work with hundred of kilograms of flour and water. Professional bakers have control over how long to mix/knead, rise (ferment/proof), bake, and over oven temperature. Ingredients are mixed and kneaded in large industrial mixers, fermented, put into pans and put into ovens, baked, turned out and packaged. The dough goes into pans in small irregular lumps. It has to rise and flow to fill the pan, spring when pans go in the oven, but not spring above the limited headspace of the pan. Professional bakers may use 10-15 minutes of “intensive mixing” – the mechanical mixing of yeasted white flour dough was dominant in professional bakeries for French loaves until Raymond Calvel devised the hybid style in the 1960s. Intensive mixing develops gluten in white flour rapidly. Home bakers with stand mixers use slower speeds due to limitations of machinery (see the stand mixer review by America’s Test Kitchen in print and YouTube) or to use a hybrid, modified or improved mixing method. Overmixing is a risk for professional bakers using industrial mixers. Machine mixing can stretch dough too much or too often, breaking the gluten strands. An overmixed dough cannot hold the gases, and will not rise.  Intensive mixing may affect a loaf with effects short of the complete failure caused by overmixing. Home bakers can have the same problem.

Mixers available to the home baker:

• Food processors can mix dough, although a food processor might only handle 3 cups of flour, and has one speed – very fast.  The mixing time may be less than a minute.  Some food processors have a dough speed and/or special blade to mix dough. The risk of overmixing dough in a food processor is well recognized. 
• A home stand mixer can handle several cups of flour, at low-medium speed settings.  The power output of a Kitchen Aid stand mixer with a 5 quart bowl may be 325 watts.  Larger stand mixers may output 800 watts.  A Bosch Compact Kitchen Machine may output 400 watts into its dough hook in its stand mixer configuration. They have to be used at the right settings and for a short time.
• A bread machine can mix and knead dough using the machine’s dough program.