Thursday, February 26, 2009

FORMULAS AND MEASUREMENT

Bakers generally talk about formulas rather than recipes. If this sounds to you more like a chemistry lab than a food production facility, it is with good reason. The bakeshop is very much like a chemistry laboratory, both in the scientific accuracy of the procedures and in the complex reactions that take place during mixing and baking.

MEASUREMENT
Ingredients are almost always weighed in the bakeshop, rather than measured by volume, because measurement by weight is more accurate. Accuracy of measurement, as we have said, is essential in the bakeshop. Unlike home baking recipes, a professional baker’s formula will not call for 6 cups flour, for example.

To demonstrate to yourself the importance of weighing rather than measuring by volume, measure a cup of flour in two ways:
(a) Sift some flour and lightly spoon it into a dry measure. Level the top and weigh the flour.
(b) Scoop some unsifted flour into the same measure and pack it lightly. Level the
top and weigh the flour. Note the difference.No wonder home recipes can be so inconsistent!

The baker’s term for weighing ingredients is scaling.
The following ingredients, and only these ingredients, may sometimes be measured by volume, at the ratio of 1 pint per pound or 1 liter per kilogram:
• Water • Milk • Eggs
Volume measure is often used when scaling water for small or mediumsized batches of bread. Results are generally good. However, whenever accuracy is critical, it is better to weigh.This is because a pint of water actually weighs slightly more than a pound, or approximately 16.7 oz. (This figure varies with the temperature of the water.)
For convenience, volume measures of liquids are frequently used when products other than baked flour goods—such as sauces, syrups, puddings, and custards—are being made.

Units of Measure
The system of measurement used in the United States is very complicated. Even those who have used the system all their lives sometimes have trouble remembering things like how many fluid ounces are in a quart and how many feet are in a mile.

The Metric System
The United States is the only major country that uses the complex system of measurement we have just described. Other countries use a much simpler system called the metric system.

Abbreviations of U.S. Units of Measure Used
pound(lb)
ounce (oz)
gallon (gal)
quart (qt)
pint (pt)
fluid ounce( fl oz)
tablespoon (tbsp)
teaspoon (tsp)
inch (in)
foot(ft)

In the metric system, there is one basic unit for each type of measurement:
The gram is the basic unit of weight.
The liter is the basic unit of volume.
The meter is the basic unit of length.
The degree Celsius is the basic unit of temperature.
Larger or smaller units are simply made by multiplying or dividing by 10, 100,
1000, and so on.These divisions are expressed by prefixes. The ones you need
to know are:
kilo- = 1000
deci- = 1⁄10 or 0.1
centi- = 1⁄100 or 0.01
milli- = 1⁄1000 or 0.001

Formulas and Measurement
Metric Units
Basic units
Quantity Unit Abbreviation
weight gram g
volume liter L
length meter m
temperature degree Celsius °C
Divisions and multiples
Prefix/Example Meaning Abbreviation
kilo- 1000 k
kilogram 1000 grams kg
deci- 1⁄10 d
deciliter 0.1 liter dL
centi- 1⁄100 c
centimeter 0.01 meter cm
milli- 1⁄1000 m
millimeter 0.001 meter mm


Converting to Metric
Most people think the metric system is much harder to learn than it really is. This is because they think about metric units in terms of U.S. units. They read that there are 28.35 grams in an ounce and are immediately convinced that they will never be able to learn metrics. Do not worry about being able to convert U.S. units into metric units and vice versa. This is a very important point to remember, especially if you think that the metric system might be hard to learn. The reason for this is simple.You will usually be working in either one system or the other.You will rarely, if ever, have to convert from one to the other. (An exception might be if you have equipment based on one system and you want to use a formula written in the other.) Many people today own imported cars and repair them with metric tools without ever worrying about how many millimeters are in an inch. Similarly, if and when American bakeshops and kitchens change to the metric system, American cooks and bakers will use scales that measure in grams and kilograms, volume measures that measure in liters and deciliters, and thermometers that measure in degrees Celsius, and they will use formulas that indicate these units.They will not have to worry about how many grams are in an ounce. To become accustomed to working in metric units, it is helpful to have a feel for how large the units are.The following rough equivalents may be used to help you visualize metric units. They are not exact conversion factors.
A kilogram is slightly more than 2 lb.
A gram is about 1⁄30 oz. A half teaspoon of flour weighs a little less than a
gram.
A liter is slightly more than a quart.
A deciliter is slightly less than a half cup.
A centiliter is about 2 tsp.
A meter is slightly more than 3 ft.
A centimeter is about 3⁄8 in.
0°C is the freezing point of water (32°F).
100°C is the boiling point of water (212°F).
An increase or decrease of 1 degree Celsius is equivalent to about 2
degrees Fahrenheit.

Metric Formulas and Recipes
American industry will probably adopt the metric system someday.Many recipe writers are already eager to get a head start and are printing metric equivalents. As a result, you will see recipes calling for 454 g flour, 28.35 g butter, or a baking temperature of 191°C.No wonder people are afraid of the metric system! Kitchens in metric countries do not work with such impractical numbers, any more than we normally use figures like 1 lb 11⁄4 oz flour, 2.19 oz butter, or a baking temperature of 348°F.That would defeat the whole purpose of the metric system,which is to be simple and practical. If you have a chance to look at a French cookbook, you will see nice, round numbers such as 1 kg, 200 g, and 4 dL.
The metric measures in the formulas in this book are NOT equivalent to the U.S. measures given alongside them.You should think of the metric portion of the formulas as separate formulas with yields that are close to but not the same as the yields of the U.S. formulas. To give exact equivalents would require using awkward, impractical numbers. If you have metric equipment,use the metric units, and if you have U.S.equipment,use the U.S. units.You should rarely have to worry about converting between the two. For the most part, the total yield of the metric formulas in this book is close to the yield of the U.S. formulas while keeping the ingredient proportions the same. Unfortunately, it is not always possible to keep the proportions exactly the same because the U.S. system is not decimal-based like the metric system. In some cases, the metric quantities produce slightly different results due to the varying proportions, but these differences are usually extremely small.

The principle of using a baker’s scale is simple: The scale must balance before setting the weights, and it must balance again after scaling. The following procedure applies to the most commonly used type of baker’s scale.
1. Set the scale scoop or other container on the left side of the scale.
2. Balance the scale by placing counterweights on the right side
and/or by adjusting the ounce weight on the horizontal bar.
3. Set the scale for the desired weight by placing weights on the right side
and/or by moving the ounce weight.
For example, to set the scale for 1 lb 8 oz, place a 1-lb weight on the right side and
move the ounce weight to the right 8 oz. If the ounce weight is already over 8 oz, so
that you cannot move it another 8, add 2 lb to the right side of the scale and subtract 8
ounces by moving the ounce weight 8 places to the left. The result is still 1 lb 8 oz.
4. Add the ingredient being scaled to the left side until the scale balances.

MEASURING BY WEIGHT
A good balance scale should be accurate to 1⁄4 oz (0.25 oz) or, if metric, to 5 g. Dry ingredients weighing less than 1⁄4 oz can be scaled by physically dividing larger quantities into equal portions. For example, to scale 1⁄16 oz
(0.06 oz),first weigh out 1⁄4 oz,then divide this into four equal piles using a small knife.
For fine pastry work, a small battery-operated digital scale is often more useful than a large balance scale. A good digital scale is relatively inexpensive. It can instantly measure quantities to the nearest 1⁄8 oz or the nearest 2 g. Most digital scales have a zero or tare button that sets the indicated weight to zero. For example, you may set a container on the scale, set the weight to zero, add the desired quantity of the first ingredient, again set the weight to zero, add the second ingredient, and so on. This speeds the weighing of dry ingredients that are to be sifted together, for example.However, remember that careful weighing on a good scale is more accurate.
British bakers have a convenient method for measuring baking powder when small quantities are needed.They use a mixture called scone flour. To make a pound of scone flour, combine 15 oz flour and 1 oz baking powder; sift together three times.One ounce (1⁄16 lb) scone flour thus contains 1⁄16 (0.06 oz) baking powder. For each 1⁄16 oz baking powder you need in a formula, substitute 1 oz scone flour for 1 oz of the flour called for in the formula. In order to make formula conversions and calculations easier, fractions of ounces that appear in the ingredient tables of the formulas in this book are written as decimals.Thus,11⁄ 2 oz is written as 1.5 oz and 1⁄4 oz is written as 0.25 oz.

BAKER’S PERCENTAGES
Bakers use a simple but versatile system of percentages for expressing their formulas. Baker’s percentages express the amount of each ingredient used as a percentage of the amount of flour used. To put it differently, the percentage of each ingredient is its total weight divided by the weight of the flour,multiplied by 100%, or:
100% = % of ingredient
Thus, flour is always 100%. If two kinds of flour are used, their total is 100%. Any ingredient that weighs the same as the amount of flour used is also given as 100%.The cake formula ingredients listed on page 11 illustrate how these percentages are used.Check the figures with the above equation to make sure you understand them. Please remember that these numbers do not refer to the percentage of the total yield.They are simply a way of expressing ingredient proportions. The total yield of these percentage numbers will always be greater than 100%. The advantages of using baker’s percentages is that the formula is easily adapted for any yield, and single ingredients may be varied and other ingredients added without changing the whole formulation. For example, you can add raisins to a muffin mix formula while keeping the percentages of all the other ingredients the same. Clearly, a percentage system based on the weight of flour can be used only when flour is a major ingredient, as in breads,cakes,and cookies.However, this principle can be used in other formulas as well by selecting a major ingredient and establishing it as 100%. In this book, whenever an ingredient other than flour is used as the base of 100%.

FORMULA YIELDS

Procedure for Calculating the Weight of an Ingredient
When the Weight of Flour Is Known
1. Change the ingredient percentage to decimal form by moving the decimal point 2 places to the left.
2. Multiply the weight of the flour by this decimal figure to get the weight of the ingredient.
Example: A formula calls for 20% sugar and you are using 10 lb of flour. How much sugar do you need?
20% = 0.20
10 lb × 0.20 = 2 lb sugar
Note: In the U.S. system, weights must normally be expressed all in one unit, either ounces or pounds, in order for the calculations to
work. Unless quantities are very large, it is usually easiest to express weights in ounces.
Example: Determine 50% of 1 lb 8 oz.
1 lb 8 oz = 24 oz
0.50 × 24 oz = 12 oz
Example (metric): A formula calls for 20% sugar and you are using 5000 g (5 kg) flour. How much sugar do you need?
20% = 0.20
5000 g × 0.20 = 1000 g sugar
Ingredients U.S. Weight Metric Weight %
Cake flour 5 lb 2500 g 100
Sugar 5 lb 2500 g 100
Baking powder 4 oz 125 g 5
Salt 2 oz 63 g 2.5
Emulsified shortening 2 lb 8 oz 1250 g 50
Skim milk 3 lb 1500 g 60
Egg whites 3 lb 1500 g 60
Total weight: 18 lb 14 oz 9438 g 377.5%

Procedure for Converting a Formula to a New Yield
1. Change the total percentage to decimal form by moving the decimal point 2 places to the left.
2. Divide the desired yield by this decimal figure to get the weight of flour needed.
3. If necessary, round off this number to the next highest figure. This will allow for losses in mixing, makeup, and panning, and it will
make calculations easier.
4. Use the weight of flour and remaining ingredient percentages to calculate the weights of the other ingredients, as in the previous
procedure.
Example: In the sample cake formula in the table, how much flour is needed if you require 6 lb (or 3000 g) cake batter?
377.5% = 3.775
6 lb = 96 oz
96 oz/3.775 = 25.43 oz or, rounded off, 26 oz (1 lb 10 oz)
3000 g/3.775 = 794.7 g or, rounded off, 800 g


SELECTION OF INGREDIENTS
In addition to measuring, there is another basic rule of accuracy in the
bakeshop: Use the exact ingredients specified.
As you will learn in the next chapter, different flours, shortenings, and other
ingredients do not function alike. Bakers’ formulas are balanced for specific
ingredients.For example, do not substitute bread flour for pastry flour or regular
shortening for emulsified shortening.They won’t work the same way.
Occasionally, a substitution may be made, such as active dry yeast for
compressed yeast but not without adjusting the quantities and
rebalancing the formula.

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