Flow of Food and Temperature Control

You're doing a great job and have laid the foundation for upcoming modules.
This module focuses on the flow of food, which is the path food takes through an operation.

Biggest hazards:
- Cross-contamination
- Time-temperature abuse
The module focuses on preventing these issues.
Preventing cross-contamination is straightforward.
Preventing time-temperature abuse requires understanding the temperature danger zone.
Thermometers are crucial for preventing time-temperature abuse.

Colored cutting boards and utensil handles can help keep equipment separate.
- Red: Raw meat
- Yellow: Raw chicken
- Green: Produce
Separate raw meat, poultry, and seafood from unwashed and ready-to-eat fruits and vegetables during storage, preparation, holding, and display.
Prep raw meat, fish, and poultry, and ready-to-eat food at different times.
Prep ready-to-eat food before raw food when possible.
Clean and sanitize surfaces and utensils between each type of food.
Buying food that requires little or no handling can prevent cross-contamination.

Foodborne illnesses happen when TCS (Time-Temperature Control for Safety) food has been time-temperature abused.
TCS food has been time-temperature abused anytime it stays between $41^{\circ}F$ and $135^{\circ}F$ ( $5^{\circ}C$ and $57^{\circ}C$ ).
This range is the temperature danger zone because pathogens grow in this range.
Most pathogens grow fastest between $70^{\circ}F$ and $125^{\circ}F$ ( $21^{\circ}C$ and $52^{\circ}C$ ).
Food is being temperature abused when:
- Cooked to the wrong internal temperature
- Held at the wrong temperature
- Cooled or reheated incorrectly
The longer food stays in the temperature danger zone, the more time pathogens have to grow.
Reduce the time food spends in the temperature danger zone to keep it safe.
Food can remain in the temperature danger zone for a maximum of four hours.

Implement good policies and procedures.
- Specify which food items to check, how often, and by whom.
- Ensure food handlers understand what to do, how to do it, and why it's important.
Make correct thermometers available to staff.
Have food handlers use timers in prep areas.
Record temperatures regularly and note when they were taken.
Use simple forms for recording information (clipboards near coolers, freezers, prep areas, and cooking/holding equipment).
Limit the amount of TCS food removed from a cooler during prepping.
Ensure food handlers know what to do when time and temperature standards are not met.
- Example: If soup on a steam table falls below $135^{\circ}F$ ( $57^{\circ}C$ ) after two hours, reheat it or throw it out.

Monitoring is crucial to controlling time in the temperature danger zone.
Thermometers are important tools.
Three types of thermometers:
- Bimetallic stem thermometers
- Thermocouples
- Thermistors

Can check temperatures between $0^{\circ}F$ and $220^{\circ}F$ ( $-18^{\circ}C$ to $104^{\circ}C$ ).
Components:
- Indicator head (indicates temperature, clear markings, scaled in at least two-degree increments)
- Calibration nut (adjust for accuracy)
- Metal stem with a dimple
Stem must be inserted into the food from the tip to the dimple for an accurate reading.
Useful for checking temperatures of large or thick food.

Measure temperature through a metal probe.
Probe may or may not be permanently attached.
Temperatures are displayed digitally.
Temperature sensing area is on the tip of the probe; only the tip needs to be inserted for an accurate reading.
Good for checking both thick and thin food.
Come with different types of probes:
- Penetration probes: Sharp tips for checking internal temperature of food (especially thin food like fish fillets or ground beef patties).
- Immersion probes: For checking the temperature of liquids (soups, sauces, frying oil). Should be used to get to the center of the pot.
- Surface probes: For checking the surface temperature of flat cooking equipment (griddles).
- Air probes: For checking air temperature inside coolers and ovens.

Measure the temperature of food and equipment surfaces without touching them.
Reduces cross-contamination and food damage.
Cannot measure air temperature or internal food temperature.
Guidelines for use:
- Hold as close as possible without touching.
- Remove obstructions between the thermometer and food/equipment.
- Don't take readings through metal or glass.
- Follow manufacturer's guidelines.

Maximum registering thermometers: Record the highest temperature reached during use (e.g., dishwasher final rinse temperature).
Time-temperature indicators (TTI): Tag attached to food packaging that changes color when temperature abuse occurs during shipment or storage. Color change is not reversible.
Temperature recording devices: Placed on delivery trucks to constantly check and record temperatures during shipment.

Always follow manufacturer's directions.
Cleaning and sanitizing:
- Wash, rinse, sanitize, and air dry thermometers before and after each use to prevent cross-contamination.
- Keep storage cases clean.
- Use sanitizing solution for food contact surfaces.
- Keep plenty of clean and sanitized thermometers on hand.
Calibration: Adjust a thermometer to give a correct reading when it loses accuracy.
- Ice point method: Adjust to the temperature at which water freezes (32°F or 0°C).
- Boiling point method: Adjust to the temperature at which water boils (212°F or 100°C, depending on elevation).

Fill a large container with ice (crushed if possible).
Add tap water until full and stir.
Put the thermometer stem or probe into the ice water (sensing area submerged).
Wait until the indicator stops moving (up to 30 seconds).
Don't let the stem or probe touch the container.
Adjust the thermometer to read $32^{\circ}F$ or $0^{\circ}C$ .
- Bimetallic stem thermometer: Hold the calibration nut with a wrench and turn the head.
- Thermocouple or thermistor: Follow manufacturer's directions.