Foundations of cost control by daniel traster chapter03

chapter 3

Unit and Recipe
Conversions

Class Name
Instructor Name
Date, Semester

Foundations of Cost
Control
Daniel Traster


Opening Questions

What is the difference between
weight and volume?
Are they interchangeable?

Which tools measure weight and which
measure volume?

2


Water Universal
Water is interchangeable at

1 pt = 1 # or 1 c = 8 oz
Because of this constant, you can convert

between volume and weight on paper in
intermediate steps as long as you return to
the original type of measure (weight vs.
volume) at the end.

3


Table 3.1
• Review table 3.1
• Which measures are American/British?
• Which are metric?

4


Table 3.2 and Figure 3.1
• These facts must be memorized in order to
convert units
• Practice daily until they become second
nature
• You cannot convert units without them!

5


Three Methods to Convert Units
Unit Size
Operation
Technique

Left/Right
Operation
Technique

Dimensional
Analysis

• You only have to
learn one
• Choose the one
that makes the
most sense to
you

6


Unit Size-Operation Technique
Going from a larger
size unit to a smaller
one, multiply the
number (to get more of
those tiny units)

Going from a smaller
size unit to a larger
one, divide (to get
fewer of the big units)
7

Example 3a
How many ounces are in 2 ¼ pounds?

Pounds (big) to ounces (small)
Unit down, number up = multiply
Ratio is 16 oz = 1#, so multiply by 16
2.25 # X 16 = 32 oz

8


Example 3b
8 cups equals how many gallons?

Cups (small) to gallons (big)
Unit up, number down = divide
Ratio is 16 c = 1 Gal
8 c ÷ 16 = ½ Gal

9


Example 3c
(requires intermediate steps)

How many Kg of water are in 2 Gal?

1 Kg = 2.2 #, 1 pt = 1#, 1 Gal = 8 pt

2 Gal (big) to pt (small) = multiply
2 Gal X 8 = 16 pt
1 pt = 1 #, so 16 pt = 16 #
16 # (small) to Kg (big) = divide
16 # ÷ 2.2 = 7.27 Kg
10


Left/Right-Operation Technique
Memorize in order

Larg
e

Smal
l
*Units with a “/” are equal to each

11


Left/Right-Operation Technique
Moving to the right (small to large) =
divide

Larg
e

Smal
l

Moving to the left (large to small) =

12


Example 3d
How many mL are in ¾ L?

Going from L to mL, move left to right =
multiply
1 L = 1000 mL
0.75L X 1000 = 750 mL

13


Example 3e
How many quarts are in 17 cups?

Going cups to quarts you move left to right =
divide
1 qt = 4 c
17 c ÷ 4 = 4.25 or 4 ¼ qt

14


Example 3f
(requires intermediate step)

How many mL are in a 16 oz bottle of water?
1000 mL = 1 L and 1 L = 33.8 oz
Move oz to L (left to right) = divide
16 oz ÷ 33.8 = 0.47337 L
(don’t round on an intermediate step)
Move L to mL (right to left) = multiply
0.47337 X 1000 = 473.37 or 473.4 mL

15


Dimensional Analysis
1. Write the ratios as fractions
2. Orient the fractions to the units cancel (each
denominator’s unit is the same as the
preceding numerator’s unit)
3. Multiply the fractions
4. Any units not canceled out remain in the
answer in their same position (numerator or
denominator)

16


Example 3g
How many L does 2 ¾ pt represent?
L = 33.8 oz and 1 pt = 16 oz

2.75
pt

X

X

=

1.302 L or 1.3 L
To compute, enter the starting number in a
calculator. Then multiply by the numerators
and divide by the denominators.
17


Example 3h
How many cups are there in 2.35 gallons?
1 Gal = 16 c

2.35
Gal

X

=

37.6 c

18

Why are Recipes Converted?
• Chef may have a recipe using metric (or
British) units but the kitchen tools only
measure in the other system’s units
• Chef has converted a recipe’s yield, and it is
more practical to measure the ingredients in
different units

19


How to Adjust a Recipe’s Yield
STEP 1: You must know the original (old) yield
and the desired (new) yield for the recipe.
Calculate a conversion factor
(CF)

C
F

=

20


Example 3i
What is the conversion factor to change a recipe
yielding 75 portions to one yielding 20 portions?

C

F

=

=

=

0.266 or 0.27

21


Conversion Factor
If the portion size of the recipe changes, you
must calculate the total weight (or volume) of
each recipe’s yield before using the conversion
factor formula.

Total Yield = total portions X
portion size

22


Example 3j
Calculate CF to convert a recipe yielding 4
one-pound loaves of bread to one yielding
110 two-ounce rolls.
Old Yield = portions X size = 4 X 1 # = 4 #

New = 110 X 2 oz = 220 oz

The units don’t
match!!!

Convert # to oz before proceeding
4 # X 16 = 64 oz

23


Example 3j (cont.)

C
F

=

=

=

3.4375 or
3.44

The formula only works if the units for
new and old yield match.

24

How to Adjust a Recipe’s Yield
STEP 2: Multiply the conversion factor times
each ingredient in the recipe to get a recipe that
will produce the new yield.

New Ingredient Quantity = Old Ing. Q X CF
The biggest challenge is converting the unit to
make the new ingredient quantity
measurements practical in the real world.

25