Module 4: Introduction to the flow of food
Bimetallic Stemmed Thermometer
-Can check temperatures from 0°F to 220°F. -This makes it useful for checking both hot and cold types of food. -Used to check temperatures during the flow of food. -Measures temperatures through its metal stem. -Insert the stem into the food up to the dimple -Useful for checking the temperature of large or thick food, not thin food, such as hamburger patties The 3 must have features: -Calibration unit: -Adjust the thermometer to make it accurate -Easy to read markings: -Clear markings reduce the chance someone will misread the thermometer -Must be sealed in at least two-degree increments -Dimple: -Mark on the stem that shows the end of the temperature sensing area.
Thermocouples and Thermistors
-Common in restaurant and foodservice operations. -They measure temperatures through a metal probe and display them digitally. The sensing area on thermocouples and thermistors is on the tip of the probe. -Good for checking the temperature of thick and thin food.
Calibrating Thermometers
Boiling point method: -Involves adjusting the thermometer to the temperature at which water boils at 212 degrees F. Ice point method: -Involves adjusting the thermometer to the temperature at which water freezes at 32 degrees F. The ice point method is easier and safer. The steps include: -Fill a large container with ice and add tap water until the container is full -Put the thermometer stem or probe into the ice water and wait for 30 seconds or until the indicator stops moving -Adjust the thermometer to 32 degrees F. -To calibrate: follow the manufacturer's directions
Types of Probes
Immersion probes: -Used to check the temperatures of liquids. -ex.) Soups, sauces, and frying oil Surface probes: -Used to check temperatures of flat cooking equipment. -ex.) griddles Penetration probes: -Used to check the internal temperature of food -Especially useful for checking the temperature of thin food. -ex.) hamburger patties or fish fillets Air probes: -Used to check the temperature inside coolers and ovens.
Other Temperature-recording devices
-Maximum registering thermometer: -Indicates the highest temperature reached during use and is used where temperature readings cannot be continuously observed. -Works well for checking the final rise temperature of dishwashing machines. -Time temperature indicator: -Monitors both time and temperature -These tags are attached to packaging by the supplier -A color change appears in the window if the food has been time temperature abused during shipment or storage. -Color change is not reversible -Temperature recording devices: -Some suppliers place them in their delivery trucks -Constantly check and record temperatures -Can check the device during receiving to make sure food was at safe temperatures while it was being shipped
Infrared (laser) thermometers
-Measures the temp of food and equipment surfaces. -Don't take readings through glass of metal. -Don't need to touch a surface to check its temperature -This means there is less chance for cross-contamination and damage to the food. -Cannot measure air temperature or the internal temperature of food. Follow these guidelines when using infrared thermometers: -Distance: -Hold the thermometer as close to the food or equipment WITHOUT touching it. -Barriers: -Remove anything between the thermometer and the food, food package, or equipment -Do not take readings through metal, such as stainless steel or aluminum. -Do not take readings through glass -Manufacturer's Directions: -Always follow the manufacturer's guidelines. -Should give you the most accurate readings
Time-temperature control
-Most foodborne illnesses can happen because TCS food has been Time-temperature abused. -TCS food has been time-temperature abused any time it remains between 41 degrees F and 135 degrees F. -Also called the temperature danger zone, because the pathogens grow in this range. -Most pathogens grow much faster between 70 degrees F and 125 degrees F. -Food is being temperature abused whenever it is handled in the following ways: -Cooked to the wrong internal temperature -Held at the wrong temperature -Cooled/reheated incorrectly -The longer food stays in the temperature danger zone, the more time pathogens have to grow. -To keep food safe, reduce the time it spends in this temperature range. If food is held in this range for 4 hours or more, throw it out.
Cross-Contamination
-Pathogens can be transferred from once surface or food to another. -Knowing how and where it can happen can be easy to prevent it -Keep raw and ready-to-eat food away from each other -To prevent, you must wash, rinse, and sanitize equipment before and after use
General Thermometer Guidelines
-Should know how to use and care for each type of thermometer and always follow the manufacturer's directions Cleaning and Sanitizing: -Thermometers must be washed, rinsed, sanitized, and air dried. -Keep storage cases clean -Make sure the sanitizing solution is for food-contact surfaces -Do this before and after the use to prevent cross contamination -Always have plenty of clean and sanitized thermometers Calibration: -Thermometers must be calibrated when they lose their accuracy -Calibrate them regularly Calibrate thermometers at these times: -After they have been bumped or dropped -After they have been exposed to extreme temperature changes -Before deliveries arrive -Before each shift Keep in mind: -Some thermometers can't be calibrated and must be replaced -Others will need to be sent back to the manufacturer for calibration -Always follow the manufacturer's directions regarding calibration Accuracy: -Thermometers used to measure the temperature of food must be accurate to within +/- 2 degrees F. -Thermometers used to measure AIR temperature in food-storage equipment must be accurate to within +/-3 degrees F. Glass Thermometers: -Candy thermometers can be a physical contamination if they break -Can only be used when enclosed in a shatterproof casing Checking temperatures: -When checking the temperature of food do the following : -Insert the probe into the thickest part of the food -Usually in the center -Take another reading in a different spot -Temperatures may vary in different areas Allow at least 15 seconds after inserting the bimetallic stemmed thermometer stem into the food
Hazards in the flow of food
-The flow of food: -The path food takes through the operation -It begins when you buy the food and ends when you serve it -Managers are responsible for the safety of the food at every point during the flow of food
Monitoring Time and Temperature
-To keep food safe, control the amount of time it spends in the temperature danger zone. This requires monitoring. -The most important tool to monitor temperature is the thermometer. -The 3 types are commonly used in operations: -Bimetallic stemmed thermometers -Thermocouples -Thermistors
Avoiding Time-Temperature Abuse
Monitoring: -Learn which food items should be checked, how often, and by whom. -Make sure food handlers understand what to do, how to do it, and why it is important. Tools: -Make sure the correct kinds of thermometers are available. -Give food handlers their own thermometers -Use timers in prep areas to check how long food is in the temperature danger zone. Recording: -Have food handlers record temperatures regularly -Make sure it is written down when the temperatures were taken -Print simple forms for recording information -Post them on clipboards outside of coolers and freezers, near prep areas, and next to cooking and holding equipment Time and temperature control: -Have procedures to limit the time TCS food spends in the temperature danger zone. -Include limiting the amount of food that can be removed from a cooler when prepping the food Corrective Actions: -Make sure food handlers know what to do when time and temperature standards are not met. -ex.) if you hold soup on a steam table and its temperature falls below 135 degrees F after two hours, you might reheat it to the correct temperature or throw it out.
Guidelines for preventing cross-contamination between food
Use separate equipment for raw and ready-to-eat food: -Each type of food should have separate equipment -ex,) use one set of equipment for raw poultry, another for raw meat, and another for produce. -Colored cutting boards and utensil handles can help keep equipment separate. -The colors tells the staff which equipment to use with each food item. -ex.) yellow for raw chicken, red for raw meat, and green for produce Clean and Sanitize before and after tasks: -Clean and sanitize all work surfaces, equipment, and utensils before and after each task. -When cutting raw chicken, you cannot get by with just rinsing the equipment. -Pathogens such as nontyphoidal salmonella can contaminate food through cross-contamination. -To prevent: All equipment must be washed, rinsed, and sanitized. Prep raw and ready-to-eat food at different times: -If you need to use the same prep table for different types of food, prep raw meat, fish, and poultry at a different time than read-to-eat food. -You must clean and sanitize all work surfaces and utensils between each type of food. -By prepping ready-to-eat food before raw food, you can reduce the chance for cross-contamination Buy prepared food: -Buy food that does not require much prepping or handling . -ex.) Buy precooked chicken breasts or chopped lettuce
