Presentation on theme: "Unit and Recipe Conversions"— Presentation transcript:
1Unit and Recipe Conversions chapter 3Unit and Recipe Conversions
2Opening Questions What is the difference between weight and volume? Are they interchangeable?Which tools measure weight and whichmeasure volume?
3Water is interchangeable at Water UniversalWater is interchangeable at1 pt = 1 # or 1 c = 8 ozBecause 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.
4Table 3.1 Review table 3.1 Which measures are American/British? Which are metric?
5Table 3.2 and Figure 3.1These facts must be memorized in order to convert unitsPractice daily until they become second natureYou cannot convert units without them!
6Three Methods to Convert Units Unit SizeOperationTechniqueDimensionalAnalysisLeft/RightYou only have to learn oneChoose the one that makes the most sense to you
7Unit 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)
8Example 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 # X 16 = 32 oz
9Example 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
10Example 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
11Left/Right-Operation Technique Memorize in orderLargeg/mLtspTbspozcpt/#qtL/KgGalSmall*Units with a “/” are equal to each other
12Left/Right-Operation Technique Moving to the right (small to large) = divideLargeg/mLtspTbspozcpt/#qtL/KgGalSmallMoving to the left (large to small) = multiply
13Example 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
14Example 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
15Example 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 = L (don’t round on an intermediate step) Move L to mL (right to left) = multiply X 1000 = or mL
16Dimensional Analysis1. 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)
17Example 3g 2.75 pt How many L does 2 ¾ pt represent? L = 33.8 oz and 1 pt = 16 oz2.75 ptXX=1.302 L or 1.3 LTo compute, enter the starting number in a calculator. Then multiply by the numerators and divide by the denominators.
18Example 3h 2.35 Gal 37.6 c How many cups are there in 2.35 gallons? 2.35 Gal37.6 cX=
19Why are Recipes Converted? Chef may have a recipe using metric (or British) units but the kitchen tools only measure in the other system’s unitsChef has converted a recipe’s yield, and it is more practical to measure the ingredients in different units
20How 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)CF=
21Example 3iWhat is the conversion factor to change a recipe yielding 75 portions to one yielding 20 portions?CF0.266 or 0.27===
22Total Yield = total portions X portion size Conversion FactorIf 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
23The units don’t match!!! 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 ozThe units don’t match!!!Convert # to oz before proceeding4 # X 16 = 64 oz
24The formula only works if the units for new and old yield match. Example 3j (cont.)CFor 3.44===The formula only works if the units for new and old yield match.
25How 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.
26Example 3k Chicken Piccata Convert the following recipe to serve 12 portions.Chicken PiccataYield = 100 portionsChicken breast, boneless, 4 oz, pounded flat eaFlour, all-purpose ¼ #Butter #Lemon juice qtChicken stock ½ qtCapers, drained, 28 oz jar jarParsley, chopped fine ½ c
27Multiply 0.12 X each ingredient’s quantity Example 3k (cont.)CF0.12===Multiply 0.12 X each ingredient’s quantity
28Units Adjusted and Rounded Example 3kChicken Piccata Yield = 12 portionsItemOldCFNew(Old X CF)Unit RatioUnits Adjusted and RoundedChix breast100 ea0.1212N/A12 eaFlour2.25 #0.27 #1 # = 16 oz4.32 or 4 ¼ ozButter3 #0.36 #5.76 or ¾ ozLemon juice1 qt0.12 qt1 qt = 4 cOR 1 qt = 32 oz0.48 or ½ cOR 3.84 or 4 ozChix Stock2.5 qt0.27 qt1.08 or 1 cOR 8.64 or 8.5 ozCapers 28 oz jar1 jar0.12 jar1 jar = 28 oz3.36 or 3.5 ozParsley, chopped1.5 c0.18 c1 c = 16 Tbsp2.88 or 3 Tbsp
29Notes on 3k Solution No unit conversion for “each.” Rounding depends on measurement tools available.Lemon juice and stock convert to oz only because they are mostly water.Non-standard ratios (1 jar = 28 oz) are learned from labels or a kitchen test.Choice of unit and how much to round can impact precision of the measurement.