Author: Tony Dalmyn

Table of Contents

• Flour
• B% (Bakers’ formula, or bakers’ ratio
• Water
  • Plain Water
  • Milk, Honey, Eggs, Syrups
• Yeast and Salt
  • Yeast
  • Salt
  • Weighing
• Conversions, Volume and Weight

Flour

Flour, whether refined and milled fine or coarse, is the ground product of grains. It contains plant proteins and starch. Starch is the carbohydrate in bread, and the ingredient thing that makes it food. Starch consisted of complex molecules of glucose and more complex sugars. The molecules react when exposed to water. Starch begins to dissolve which creates the condition when sugar in starch feeds yeast – fermentation. The proteins react to water by making dough sticky and stretchy.

The United States has eight classes for wheat: Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, Soft White, Unclassed, and Mixed.Wheat and flour standards are based on the practices of the milling companies, in classifying wheat. Daniel DiMuzio discussed this in his printed book, Bread Baking, An Artisan’s Perspective (2010) at pp. 16-18. Wheat is classified on:

• protein content (hard or soft);
• kernel color (red or white)
• planting season (spring or fall called “winter wheat”).

Bread flour is made from hard red spring, hard red winter, and hard white winter wheat. The USDA FoodData Central Legacy foods database reports that 100 g. of enriched white bread flour contains 12 g. of protein (12%).

In Canada, wheat is classified in regulations under the Canada Grain Act. Wheat classes are established by the Canadian Grain Commission, which has revised the classes in response to consultation with growers and processors. In Canada a 2015 book called Understanding Ingredients for the Canadian Baker (published under a Creative Commons Licence) noted in Chapter 1.9, as to All-Purpose and Bread flour sold in Canada:

General purpose or home use flours are usually a blend of hard spring wheats that are lower in protein (gluten) content than bread flours. They are top patent flours and contain sufficient protein to make good yeast breads, yet not too much for good quick breads, cakes, and cookies.

….

Bread flour is milled from blends of hard spring and hard winter wheats. They average about 13% protein and are slightly granular to the touch. This type of flour is sold chiefly to bakers because it makes excellent bread with bakery equipment, but has too much protein for home use. It is also called strong flour or hard flour and is second patent flour.

A recipe will describe the kind of flour, as well as the amount. The purposes of this kind of formula are to mix the right amounts of water, yeast and salt to get the right kind of bread,to predict how much dough to expect, and to organize the other steps of the baking process. Recipes for the home baker usually list ingredients by volume – cups, tablespoons etc.  A recipe for a 1 lb. loaf of bread requires 2 cups of white bread flour or whole wheat flour.  By the early 20th century, most recipes referred to a standard measuring cup, which could vary depending on where the recipe was published:

• A US cup is .87 of an Imperial (U.K., many other English speaking countries) cup. An Imperial cup is 1.2 US cups;
• A metric cup is a quarter liter (250 millilitres) which is .88 Imperial cups or 1.06 US cups.

The method of filling the measuring cup affects the density and the weight of one cup. When a measuring cup is put into flour and used to scoop the flour, the flour is more dense. When flour is scooped with a scoop and or spooned into a measuring cup, it is less dense. There is a range of weights for a USA cup of (white) bread flour in the sources:

• 4.25 oz. = 121 g. See: King Arthur Flour ingredient weight chart. King Arthur Flour’s method is to use a scoop, “fluff and sprinkle” and level the top of the measuring cup.;
• 4.5 oz. = 128 g. Peter Reinhart (The Bread Baker’s Apprentice, and other books) says 4.5 oz.; he measures flour scooped in a scoop and poured into the measuring cup;
• 4.875 (i.e. 4 and 7/8) oz. = 138 g.;
• 4.9 oz. = 139 g.;
• 5 oz. = 141 g. The Bread Lover’s Bread Machine Cookbook (BLBMC) suggests 1 cup of bread flour or whole wheat flour converts at 5 oz. 

Whole wheat flour ranges from 4 oz. = 113 g. (King Arthur) to nearly 5 oz. per cup (BLBMC). While whole wheat and bread flour weigh nearly the same amount per unit of volume, bread flour has more of the proteins that bond to form gluten. It is mixed, kneaded and handled differently.

Many recipes round flour and water to the nearest quarter cup. The Bread Lover’s Bread Machine Cookbook (Harvard Common Press, 2000; by Beth Hensperger) goes to the nearest 1/8 cup. 

Measuring by weight is the standard for commercial baking. Scales in ounces go down to 1/8 oz, but not necessarily to decimal fractions.  Metric kitchen scales go to the nearest gram. That is close enough for flour. Converting a recipe involves interpreting the recipe and making assumptions about the writer measured ingredients, and assumptions about ingredients. Errors in conversion and mistakes in arithmetic (e.g. slips in entering numbers in a calculator) can change the dough and the loaf. A recipe may list flour by weight, or a book may discuss conversion. Where recipes provide weight, I refer to weight. If not, I guess and experiment. In recipe conversion usually drag-scooped cups are more appropriate.

For bread machine bread, I weigh (white) bread flour (Canadian All Purpose) and whole wheat flour at 139 g. per cup in a recipe.

Zorjirushi bread machine manuals recommend scooping and filling measuring cups or weighing. The Zojirushi recipes imply:

Ingredient	Volume	Weight	1 cup =
Bread Flour	4 ¼ cups	544 g.	128 g.
Whole wheat flour	4 ¾ cups	570 g.	120 g.

B% (Bakers’ formula, or bakers’ ratio

Baker percentage (B%), a method of managing the production of bread. It is explained in a some baker cookbooks, For instance Peter Reinhardt devotes pages 40-45 of The Bread Baker’s Apprentice to this topic. It is a tool taught to professional bakers, and addressed in texts such as Daniel T. DiMuzio’s Bread Baking; An Artisan’s Perspective. For the baker-manager, it is a calculation to scale inputs to create 2, 10, 100 or 1,000 consistent loaves of bread. The assumptions are consistency of ingredients, equipment, energy, working space, and time.  For managing production, every ingredient is put into the formula.  It is as precise as it needs to be, for how it is used. B% is explained:

• Bread Bakers Guild of America;
• The Fresh Loaf;
• King Arthur Flour;
• Bakers Percentage Revised – The Artisan Net article;
• Baker Percentage – Wikipedia Article;
• Bread Magazine, Math for Bakers.

B% is a list of ingredients by weight, for a batch of dough – an instruction to make baking consistent and get the same result every time. . The professional baker will have to mix enough dough to bake dozens or hundreds of loaves, divide it, shape it and bake it. The essential ingredients – flour, water, yeast and salt – need to be measured, mixed, fermented and baked the same way. The home baker uses less ingredients and will only make a few loaves in one session.

The simplest version of the formula or ratio starts with the weight of the four essential ingredients. The weight of flour is treat as 100%, The weight of salt and yeast are noted and calculated as a percentage of flour weight. Water is weighed and is also calculated as a percentage of flour weight – the percentage is called hydration.

A couple of simple recipes follow. The first is a dough for 2 batard loaves of French bread. The second is for 2 pounds of bread, followed by dough for several loaves of ciabbata or baguette

	Weight	Percent	what	By volume, approx.
White Flour	580 g.	100	flour weight	4 cups
Water	406 g.	70	hydration	1 ¾ cups
Instant Yeast	4 g.	.7		1 ½ tsp.
Salt	12 g.	2		2 tsp.
Total		172.7	percentage total

	Ciabbata	Ciabatta %	Baguette	Baguette %
Bread Flour	1377 g.	100	2156 g.	100
Water	1060 g.	77	1488 g.	69
Instant Yeast	10 g.	.7	12 g.	.6
Salt	28 g.	2	54 g.	2.5
		179.7		172.1

When one type of flour is used, the flour weight is the total flour weight.

When different flours are combined, the weights are added to determine total flour weight, even when flours differ in density and protein content. The relative amounts of flour are identified as a percentage of the total flour weight (e.g. 50% bread flour and 50% whole wheat; or 90% bread flour and 10% rye flour). It gets complicated. While any dry ingredient can be weighed and a B% calculated, not all dry ingredients count for Total Flour. The total flour weight can be the sum of the weights of:

• flour, including any grain product such as rolled oats, grain meal or vital wheat gluten (gluten flour); or
• all dry ingredients except salt, yeast, dry seeds, and fruit.

The weight of every ingredient can be listed and expressed as a percentage of the total flour weight. When the of flour, salt, yeast and water percentages are added up, the sum of percentages is well over 100%. A wet dough for a ciabatta bread will add up to 179%. This means the wet dough weighs 179% of the dry flour alone, at the beginning of the process.

I use mainly use metric weight; I may also note US ounces.

Nutrition Facts labels on bags of flour may suggest the weight of a quarter cup of flour. Online conversion calculators and tables also may appear to be useful. These are based on software that hook into the US Department of Agriculture (USDA) Data Cental tables or other data, which may use loosely filled cups, rather than drag-scooped cups. Other flours might graph to a mean, but show more variability. These numbers are high and can be reduced by a few grams per cup.

White Whole Wheat flour is mentioned in a recipe from BLBMC (p. 127) “White Whole Wheat Flour Bread”. (see variation with 3 cups of flour). It is supposed to work like bread flour; a loaf is supposed to work on basic bake, which is a “white bread” cycle. It is available from King Arthur mills in the USA:

White whole-wheat flour is … made with hard white spring or winter wheat — the bran, germ, and endosperm are all ground to result in another 100 percent whole-wheat flour. … because it’s made with hard white wheat instead of hard red wheat, like whole-wheat flour, it has a paler color and its taste is milder. It’s still nuttier than all-purpose flour because it includes the fibrous bran and germ of the wheat, but it’s a more approachable whole-wheat flour, particularly for those who don’t enjoy the hearty taste of whole-wheat flour.

It can be used interchangeably with whole-wheat flour in any recipe

https://www.kingarthurflour.com/learn/guides/white-whole-wheat

I substituted Rogers “Whole Wheat Bread Flour”, for White Whole Wheat in a recipe. The Rogers product was an enhanced whole wheat flour, higher in protein (gluten) than the flour in the recipe. It was a lesson. I stopped looking for flour that can’t be obtained in this part of Canada.

Water

Plain Water

In a simple recipe, there is just water. A cup depends on the recipe and the context. A cup of water,

• USA standard, is 236.6 grams, which rounds up to 237 g. (in the metric system one milliliter of water is one gram).
• An Imperial cup of water converts to 284 grams.
• A metric cup of water is 250 grams.

Too much water is cited by many sources as a cause of some kinds of failure – weak and sunken loaves.  Too much is in relation to the amount of flour that is being hydrated, and the mixing or kneading action of the machine. An extra 30 grams (1/8 cup = 2 tbsp.) of water into 3 cups of flour means a wet sloppy dough.  The goal is tenacious and somewhat elastic (i.e. that pulls back to its original size and shape) dough that is also extensible – it relaxes.  T

Milk, Honey, Eggs, Syrups

A recipe may include milk, syrup, eggs, butter or vegetable oil. Wet ingredients, except oils extracted from pressed seeds, are water with sugar, fat and protein molecules suspended or dissolved in water. The water in a wet ingredient will interact with flour if it is not already bonded to something else. Any wet ingredient can be weighed and a B% calculated, but not all wet ingredients are counted as water. When a water-based fluid like milk is the only water in a dough, the weight of the milk is used to calculate hydration of the dough. Milk is nearly all water, but not all of the water is available to bond to the starch in flour – only 85 to 90%. 1 + 1/4 cups of skim milk has 1 + 3/16 cups (1 cup + 3 Tbsp.) of water. Some water remains bound to natural milk sugars including lactose and to milk fats. A cup of fluid cow’s milk weights 244-245 grams and contains about 12 g. of lactose and other milk sugars according to USDA averages. The sugars are hygroscopic but milk has ample water to hydrate the flour. Whole milk should be 3.25% butter fat. 2% milk, 1% milk, and non-fat (or skim) milk are reduced fat milk products.

Reconstituted milk (powder and fresh water) is nearly the same as milk. The ingredients on packages of milk powder and on the Web vary. The ratio of powder to water may be 4 or 5 Tablespoons to 1 cup. It depend on the brand and one use choices. Substituting powdered milk and water for fluid milk can be approached by mixing the powder and water and pouring the reconstituted milk into the measuring vessel, using the reconstituted milk in the amount in the recipe. In mixing the milk, 1 cup of water will gain weight but will only slightly change volume.

Unpasteurized milk can lead to surprizes. Some bakers think milk,  real or reconstituted, should be scalded to denature proteins. Mostly dry milk is produced by baking to dry out the water. The heat denatures the protein.

Butter, maple syrup, honey and other syrups have some water. The home baker’s trick is reduce water in a recipe by 1/4 cup for 1 cup of honey, when honey is used to replace sugar. The average for honey in the US and Canada is 17 g water per 100 g of honey. The typical pure maple syrup for sale in the US or Canada is 32 grams of water per 100 grams of syrup. A large egg, in the Canadian egg grading system, is about 57 g.  A large egg contributes 36 g. to hydration – nearly 3/16 of a cup of water.

For ingredients that are largely water – i.e. milk, butter, eggs, syrups – rather than seed or vegetable oil I note weight of water, taken from conversion tables.

Wet ingredients that contain water may be noted to see if a dough has a higher real hydration rate than a simple calculation implies. Ingredients that contain water are not necessarily counted directly in industrial B% – it involves conversions and extra math. Water content of baking ingredients can be calculated by referring the USDA Food Composition Databases. For a Canadian product, the Canadian Nutrient File may have the value. Using the databases takes some practice. Not all of the water reported in the data is released from the source ingredient and incorporated into dough. It may be necessary to use a teaspoon or two more water to get the hydration right.

I put in oil by volume and do not bother to weight it or calculate a ratio.

Yeast and Salt

Yeast

Yeast means yeast organisms commercially grown, preserved, packaged, and distributed as a leavening agent. Most grocery stores carry active dry yeast and smaller grained dry yeast: instant yeast, quick-rise/rapid-rise yeasts, or “bread machine” yeast. Cakes and blocks of fresh yeast are rare, and not usually mentioned in home baking recipes. Recipes may refer to active dry yeast by volume (tablespoons and teaspoons); or by packets. Active dry yeast was and is still sold in foil packets containing .25 oz. of yeast. This was a tablespoon at one time. Active dry yeast became somewhat denser and finer grained. A packet of modern active dry yeast is about 2.25 teaspoons, but is still .25 oz. = 7 grams. A 7 gram/.25 oz. packet of modern active dry yeast is equivalent to 2 tsp. (6.2 grams) of instant yeast. Bread machine recipes refer to Instant yeast, bread machine yeast or active dry yeast. Conversion is simple if a recipe refers to instant yeast or to quick rise or “bread machine yeast. 1 tsp = 3.1 g. I tried to make conversions from active dry to instant yeast fast and simple with a table, which is in my post Dry Yeast.

Salt

Salt has several effects:

• it alters or enhances the flavour of bread,
• it preserves bread, for a few days, against some microbial infestation
• it interacts with amino acids making up the gluten proteins, and affects the elasticity of dough. Less salt means a less elastic and tenacious dough.
• it inhibits the yeast and slows the fermentation.

Thebakers’ rule of thumb is that when salt is decreased, yeast should also be decreased. This avoids an overinflated loaf that will collapse or overflow the baking pan, But the effects of salt on bread dough and baking are complicated.

Recipes that say “salt” always refer to ordinary table salt, unless a particular type or brand is stated. Some table salts are fine-grained and denser. Kosher salt has large crystals and it less dense. A baker measuring by volume should be aware of the differences, but crystal size do not affect measurement by weight. 1 tsp of ordinary table salt = 5.7 g. For quick reference in baking and bread machine baking, I read a refererence in a recipe as table salt, conventionally ground, and convert to weight:

Volume tsp. fraction	Volume tsp. decimal	Weight grams
1	1	5.7
7/8	.875	4.99
3/4	.75	4.3
5/8	.625	3.6
1/2	.50	2.8
3/8	.375	2.1
1/4	.25	1.4
1/8	.125	0.7

Weighing

For bread machine baking, yeast and salt should be measured to .1 gram, which requires a small high precision scale. This item is more expensive than measuring spoons, but important. Some brick and mortar retail stores sell high precision scales. There are several inexpensive scales available online.

Conversions, Volume and Weight

The King Arthur Flour ingredient weight table is good, but refers to ingredients as if all suppliers of a particular item have uniform standards and methods. I keep my data about baking ingredients in a spreadsheet on a local (i.e. where I am) device, rather than on a remote server on the Internet in the cloud.

Table of Contents

• Introduction
• Yeast: Science, Technical, historical
• Dry Yeasts
  • Measurement
  • Active Dry
  • Instant Yeasts
  • Peaks
  • Converting Active Dry to Instant
• Bread Machine

Introduction

In 1999, Beth Hensperger, in her Bread Bible said that the yeast on the market for the home baker included cakes of fresh yeast and a few types of dry yeasts:

• active dry yeast;
• instant; and
• quick-rise and/or rapid-rise.

The use of fresh yeast (yeast cakes or compressed yeast) in home baking was rare by 1999 – recipes or formulas that mention fresh yeast were decades old.

Most home baking books published in English after about 1950 had been written with active dry yeast as the yeast to be used. It a dry powder. The particles are clumps of dormant living yeast organism, in shell of dead yeast cells. It needs to be exposed to water. The common practice, called proofing, was to soak dry yeast in warm (not hot) water to break up the dead cell coating and revive the dormant living yeast

Active dry yeast, a shelf stable granular yeast, manufactured by dehydrating yeast cells and packaging the product was the preferred product for fermentation of bread dough 20th century. The process was introduced by Fleischmann’s Yeast during World War II, and has been widely copied.

Some commercial formulas and and reference materials still refer to “fresh” yeast, compressed yeast cakes, the industrial product of cultivated yeast, processed and preserved in a wet medium, usually refrigerated.

Beth Hensperger mentioned, in her Bread Bible, bread machine yeast, then manufactured by Fleishmann’s and Red Star. She said it was finely granulated and coated with ascorbic acid. Instant yeast was new to the market. Yeast manufacturers released instant yeasts under various names. Instant yeasts, whether called instant, quick-rise, rapid-rise or bread machine yeast are dry yeasts make up of clumps of dormant cells, coated in chemicals. The clumps are smaller than clumps or grains of active dry yeast. It does not need to be proofed or activated. It become active on contact with water in a dough while the flour and water are mixed when the water dissolve the coating.

Recipes for home bakers generally use volume measurements.

Yeast: Science, Technical, historical

Yeast is a eukaryotic (single-celled) microorganisim. Yeasts are fungi. There are hundreds of species. The principal species used in processing carbohydrates in baking, brewing, and wine-making, and as a food product (nutritional yeast) is Saccharomyces cerevisiae (“S. cerevisiae”). Many varieties (“strains”) of S. cerevisiae are used in food processing, and are grown, processed, and marketed in different ways. Sources suggest that 1 gram of yeast contains about 20,000,000,000 (20 billion) individual yeast cells. This number will have been calculated from assessments of the number of cells in even smaller samples, which may have include some wet medium or dry coating.

Brewers differentiate: yeasts that form a film on top of a wort like S. cerevisiae are ale yeasts. Yeasts that accumulate and ferment on the bottom of a wort are yeasts for lagers.

The beginning of brewing and baking were historically related. However, the history of food was largely not recorded. Yeast infested grain mashes. Yeast consumed starch (fermentation) producing carbon dioxide and alcohols. Carbon dioxide trapped in webs of gluten, makes bread rise. Alcohols flavour bread, and have other purposes. These accidents started cycles of experimentation, learning and imitation.

At some points, bakers obtained yeast by buying by-products of brewing. Industrial yeast production in the 18th and 19th century produced compressed or “caked” fresh yeast in blocks or “cakes” to industrial bakers.

By 1999, yeast manufacturers were introducing new dry yeast products to the market. A proliferation of names arose because manufacturers used different techniques and marketing terms. The manufacturers do not explain (to retail consumers and home bakers) how rapid/quick-rise, instant yeast and bread machine yeast products are made, or how they differed. Specifications and methods are not noted on the packaging and are not published widely – perhaps only for some customers.

Mergers and acquisitions realigned brands. The American brand Red Star was acquired by the European manufacturer Lesaffre in 2001, and then sold to Archer Midland Daniels, and managed as joint venture. Bakipan, another American brand, for instance, said that its “Fast Rising Instant Yeast [is] … cake yeast in a semi-dormant state. The drying process in its manufacture reduces moisture content, giving it a longer shelf life than cake yeast while retaining optimum activity. … Bakipan® Fast Rising Instant Yeast is a fast-acting yeast that can shorten the rise times for traditional baking …”  

Dry Yeasts

Measurement

For cooking and baking measurement of active dry yeast, like other ingredients for home cooking, was and is usually by volume. The teaspoon is the normal unit of measurement. A teaspoon is exactly 1/3 of a Tablespoon. The exact metric conversion, to the nearest .1 millilitre is 4.9 ml. It is common for spoons to be marked indicating that 1 teaspoon is 5 ml., 1 Tablespoon is 15 ml., ½ tsp. is 2.5 ml., etc.

Some reference materials provide general comparison of the weights of fresh yeast and the varieties of dry yeast.

Peter Reinhart, the author of popular books on artisinal technique for home baking, suggested at p. 15, in Crust and Crumb (1996), that active dry yeast and instant yeast weighed about 40% and 33%, respectively, of the equivalent amount of fresh yeast. At p. 28 in The Bread Baker’s Apprentice (2001), Peter Reinhart give the values differently. The values:

Product	Weight (C&C)	Weight (BBA)	Volume (C&C)	Volume (BBA)
Fresh	1 oz.		1 Tbsp.
Active dry	.4 oz.		1.25 tsp
Active dry		.1 oz.		1 tsp.
Instant	.33 oz.	.11 oz.	1 tsp.	1 tsp.

Daniel Di Muzio, in Bread Baking, An Artisan’s Perspective (2010), said:

You need only about half the weight of [active dry] yeast called for in formulas that specify fresh yeast. …. The conversion factor [for instant yeast] versus fresh yeast is even lower. You only need 33-40 % as much instant yeast as fresh yeast …

Active Dry

Active dry yeast was developed in the 1940s. Active dry yeast was durable for months or years without refrigeration, unlike the compressed fresh yeast used by industrial bakers. Active dry yeast was and is manufactured by drying a yeast culture. The dried yeast was made up of “grains” resembling fine sand, which are actually clusters of thousands of yeast cells. The exterior of the grains was/is made of dead cells. The live dormant interior cells can be activated by putting the dry yeast in warm (not hot) water. This product had and has a serious expiry date. Active dry yeast was and is sold in 1/4 oz. (U.S.) packets. In the US, a 1/4 oz. packet was 1 Tbsp. For some years one packet 2.5 tsp. As of about 2001 it was 2.25 tsp. Old packets of old style active dry yeast have not been manufactured or sold for decades. Bread recipes from the 1940’s until the introduction of the other dry yeast varieties refer to active dry yeast. Many specify with amounts of active dry yeast in packets or by measuring spoons, by volume. Active dry yeast is measured to the nearest quarter teaspoon in many home baking recipes and bread machine recipes.

Instant Yeasts

Instant yeast “grains”mail are smaller than grains of active dry, and chemically coated in ascorbic acid (Vitamin C) and sugar. Instant yeast activates on contact with the water when the dry ingredients are mixed with the wet ingredients, and almost never needs to be activated or prehydrated to propogate. See All About Dried Yeast, What is Bread Machine Yeast, the King Arthur flour Ingredient Guide, the King Arthur web article All About Yeast, and the King Arthur blog post “Which Yeast to Use”. See also Commercial Yeast in Fresh Loaf Baker’s Handbook, and What’s the Difference between Active Dry Yeast and Instant Yeast. For the history of baking yeast, and the ways it has been presented, Lesaffre’s Explore Yeast pages are informative.  A leading baking industry paper on instant yeast: Lallemande’s Update, Volume 2 # 9.

Beth Hensperger mentioned instant yeasts sold as Regular Instant and Special Instant in her 1999 Bread Bible.

Lesaffre brought instant yeast to the market in the U.S. under its SAF brands: SAF Instant Red and SAF Instant Gold. The Gold product is osmo-tolerant, and said to be “designed especially for doughs high in sugar (sweet breads)”. Lesaffre distributes SAF Instant yeasts to home bakers in the US through quasi-wholesale mail-order and online vendors like King Arthur Flour.

Increasingly, general bread recipe books are written for instant yeast, also by volume. Books on artisanal bread baking do not distinguish quick-rise/rapid-rise yeast from instant yeast. Peter Reinhart said that instant yeast can be substituted for compressed fresh and active dry yeast for home bread baking, and for artisanal recipe uses. He came to accept that instant yeast should be re-hydrated for artisanal breads in Artisan Bread Every Day (2009) at p. 13 (although fermentation should be slowed down with refrigeration to develop flavor and other features of artisanally baked bread). Other writers agree. See:

• Peter Reinhart, Crust and Crumb (Ten Speed Press, 1998);
• Peter Reinhart, The Bread Baker’s Apprentice (Ten Speed Press, 2001);
• Peter Reinhart, Artisan Bread Every Day (Ten Speed Press, 2009);
• Robert DiMuzio, Bread Baking; An Artisan’s Perspective (Wiley, 2010).

Some recipe and baking books suggest letting the yeast and ingredients warm to room temperature. Refrigeration preserves the product. Some  sources suggest that keeping yeast cold, including dried yeast, slows it down. Reinhart noted that instant yeast is potent but slow to awake in The Bread Baker’s Apprentice at p. 32, and in later books began to suggest putting instant yeast in warm (not hot) water was useful.

Quick-rise/rapid-rise yeasts are dried and coated differently than “instant” yeast, depending on the manufacturer or processor. Some have the words “Instant Yeast” on the label. See: Yeast: Dry vs. Rapid-Rise and the thread “Fast Active Fleishmann’s vs. SAF Instant” (about pizza dough). The equivalences were debated in forums like Instant Yeast vs. Fleishmann’s Rapid-Rise.

Peaks

Yeasts, once they activate, ferment and propogate, pick up speed and hit a peak. Some compressed and active dry yeasts have a second peak – home wine makers and home beer makers encounter this with their yeasts which have a vigorous first fermentation and a secondary fermentation. Bakers may time their bulk fermentation and final proof to take advantage of each. I found a graph on SAF instant yeast gas production (with the Cyrillic text and the red line for SAF in the post by Mariana January 2, 2018 in the forum Difference in Yeast Brands). I have not found comparison graphs for other instant yeasts.

Converting Active Dry to Instant

In 1999, Beth Hensperger, writing in her Bread Bible said that a quarter ounce (US Units) “packet” of active dry yeast was a Tablespoon. Modern active dry yeast grains are finer, and the product is more dense. Modern active dry yeast is still sold in quarter ounce packets. For a few years, a quarter ounce converted to 2.5 tsp. (.83 Tbsp). More recently, leading brands Fleishmann’s, Red Star (Lesaffre), SAF (Lesaffre) state that their quarter ounce packet of active dry yeast contains 2.25 tsp.

The amount of current active dry yeast to substitute for a packet of active dry in a recipe can be determined easily:

• A quarter ounce packet is still a quarter ounce packet;
• A home baker with a jar of modern active dry yeast can scoop 2.25 tsp. of modern active dry to substitute for a “packet” of active dry in an old recipe.

Converting a specific amount by volume – e.g. 2 tsp. – of active dry yeast in an old recipe to modern active dry yeast, or to instant yeast will involve parsing the recipe to determine what an author meant, and a little math.

Differences between active dry and Instant yeast:

1. Instant yeast has smaller particles; it is denser. 1 tsp. of instant is heavier than 1 tsp. of active dry. Online sources say that 1 tsp. of instant is 3.1, 3.12 or 3.15 g,;
2. Instant yeast has less coating and has more active yeast cells. It starts fermenting faster and is more “potent”;

Product (1 tsp.)	Weight, U.S. oz.	Weight, (metric) grams
Active dry	0.1	2.83
Instant	0.11	3.12

Substituting dense, more potent instant yeast for active dry means less volume and a decrease in weight. The bakers’ rules of thumb at the end of the 20th century for converting instant and (modern) active dry yeast by volume were:

• 5 parts active dry = 4 parts instant. 1.25 tsp. active dry = 1 tsp. of instant, per Peter Reinhart; and
• 4 parts active dry 3 parts instant. 4 tsp. active dry = 3 tsp. of instant.

The 5 parts to 4 ratio suggests that the amount of instant yeast to substitute for active dry yeast is 4/5 (80%) of the active dry yeast. The ratio may be 6/7 (86%). Either ratio is close enough to be useful, if a home user mixing enough ingredients for one or two loaves can be precise whether measuring by volume or by weight.

Conversion of active dry yeast in a recipe by weight is simple, if a baker is sure that a recipe refers to an active dry yeast as effective as modern active dry yeast, which weighs 2.83 grams per teaspoon, has a scale that is precise enough and knows the right conversion factors. 1 tsp. of active dry yeast might be converted 2.1 grams of instant yeast. 80 or 85% of 2.83 g. would be 2.3 g. or 2.4 g.

Any given online converter may not use accurate information about the products, or make rounding errors. [Update -the Omni calculator, as of late 2022, is fast and close enough to be useful with the amounts used to mix dough for 1 or 2 large or medium loaves.]

More conversions, not entirely consistent. These cannot be easily measured with measuring spoons or weighed without a very precise scale:

Active dry tsp.	Active dry US oz.	Active dry grams	Instant grams	Instant US oz.	Instant tsp.
			7.02	.25	2.25
2.5		7.0	6.71	.24	2.15
2.25 1 packet after 2005	.25	6.4	6.2	.22	2
			5.5		1.75
2	.2	5.66	4.2	.18
1.75		4.9	3.65
1.5		4.25	3.13
			3.12	.11	1
1.25	.125	3.5	2.6
1	.1	2.83	2.1		.86
			1.6	.06	.5
.75		2.1	1.4
.5	.05	1.4	1.3		.43
			.8	.03	.25
.25	.025	.7	.5

Bread Machine

Beth Hensperger suggested using bread machine yeast in bread machine recipes in the Robotic Kneads chapter of her 1999 Bread Bible.

In The Bread Lover’s Bread Machine Cookbook (2000), Bread Hensperger suggested that SAF Instant Red yeast was more efficient for bread machine baking than the yeast then marketed as “bread machine” yeast. She provided different amounts for instant yeast and bread machine yeast for individual recipes. This advice was not helpful. She later stopped offering it in bread machine bread recipes published on her web site.

Instant yeasts, rapid/quick-rise yeasts, and bread machine yeasts vary in some ways, but are equivalent for bread machines. I use instant yeast in my bread machine (and for all bread baking).