soups

1. 9-1
CHAPTER 9
PRINCIPLES OF COOKING
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2. 9-2
Principles of Cooking
• Cooking can be defined as the transfer of
energy from a heat source to a food
• Energy alters the food’s molecular
structure, changes its texture, flavour,
aroma, and appearance
• When food is cooked, the process destroys
microorganisms and makes food easier to
ingest and digest
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3. 9-3
Heat Transfer
• Conduction
• Convection
– Natural
– Mechanical
• Radiation
– Infrared
– Microwave
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4. 9-4
Heat Patterns
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5. 9-5
Effects of Heat
• Proteins coagulate
– Complete coagulation at 71°C to 85°C (160°F to 185°F)
• Starches gelatinize
– Occurs gradually between 66°C and 100°C (150°F to
212°F)
• Sugars caramelize
– Begin caramelizing at 160°C to 170°C (310°F to 338°F)
• Water evaporates
– Evaporation is responsible for the drying of food during
cooking
• Fats melt
– Do not evaporate when heated
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6. 9-6
Cooking Methods
• Dry-heat:
– direct or indirect
• Moist-heat:
– submerged in liquid or exposed to steam
• Combination:
– involves dry heat and moist heat
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7. 9-7
Dry-Heat Cooking Methods
• Broiling
• Grilling
• Roasting
• Baking
• Sautéing
• Pan-frying
• Deep-fat frying
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8. 9-8
Sautéing and Pan-Frying
Sautéing
Pan-frying
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9. 9-9
Deep-Fat Frying
• Although deep-fat frying uses liquid fat, it
is a dry-heat cooking method
• Deep-fat frying uses high temperatures,
allowing the food’s surface to brown and
become crisp
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10. 9-10
Fats for Deep-Frying
• Vegetable oils are often used
– Soybean, safflower, canola, etc.
• Specially formulated frying fats are also
available
– Anti-foaming, anti-oxidant and preservative
agents are added
• Some frying fats are hydrogenated
– A process that turns liquid oil to solid fat
– Being reformulated to eliminate trans fats
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11. 9-11
Procedure for Deep-Frying Foods
Choose the Right Fat
Consider the following:
• The fat’s smoke point:
– Animal fats have a low smoke point
– Vegetable oils have a higher smoke point
• Flavour:
– Clean, natural flavour
• Resistance to chemical breakdown
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12. 9-12
Procedure for Deep-Frying Foods
Maintaining Fryer Fat
• Properly maintaining frying fat will greatly
extend its useful life
– Store fat in sealed containers, away from strong
light
– Skim food particles from the fat’s surface often
– Do not salt food directly over the fat
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13. 9-13
Maintaining Fryer Fat (cont’d)
– Prevent excessive water from coming in contact
with the fat
– Do not overheat the fat (turn down on stand by
when not in use)
– Filter the fat after each shift
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14. 9-14
Enemies of Fryer Fats
• Fryer fat can be damaged by
– Salt
– Water
– Overheating
– Food particles
– Oxygen
• Change fryer fat when it
– Becomes dark
– Smokes
– Foams
– Develops off-flavours
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15. 9-15
Deep-Fat Frying Methods
Basket method
Double-basket method
Swimming method
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16. 9-16
Moist-Heat Cooking Methods
• Poaching
• Simmering
• Boiling
• Steaming
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17. 9-17
Steaming
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18. 9-18
Combination Cooking Methods
• Braising and poêléing
• Stewing
Braising
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19. 9-19
Sous Vide
• French for “under vacuum, cooked in a bag”
• Developed by Georges Pralus in 1971 in France
• Fresh ingredients are combined, vacuum packed
in individual portions, cooked under vacuum,
chilled, then re-thermalized for service
• Widely used by hotels, restaurants and caterers,
but also in retail market
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20. 9-20
Sous Vide
• Safety concerns:
• High quality ingredients with low overall
microbe counts required
• Risk of food poisoning if there are errors in
temperature or time during preparation, storage
or handling
• Leaky packages must be identified and
discarded
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21. 9-21
Cook-Chill Sytems
• Commonly associated with institutional cooking
• Retains nutritional integrity and flavour
• Start with standardized recipe
• Cook by traditional methods then rapidly chill
according to specific temperature benchmarks
• Reheat to an internal temperature of 74°C (165°F)
or hotter for 15 minutes
• Requires care to ensure quality and food safety
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22. Nutrition and Cooking Methods
Dry-Heat Methods:
• Allow excess fat to drip away
• Using non-stick coatings allows you to use less fat
Moist-Heat Methods:
• Nutrients are not leached from foods during steaming
• Poaching in a broth or court bouillon adds no fat
• Skim visible fat when you cook foods in a liquid
Copyright © 2015 Pearson Canada, Inc. 9-22