Study guide
10.3 Dishwashing
ServSafe Food Protection Manager Certification Exam
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1 Introduction
Welcome to ServSafe Manager Certification
2 1. Providing Safe Food
1.1 Understanding Foodborne Illnesses 1.2 How Foodborne Illnesses Occur 1.3 Keeping Food Safe
3 2. Forms of Contamination
2.1 Biological Contaminants 2.2 Chemical and Physical Contaminants 2.3 Food Allergens 2.4 Deliberate Contamination and Outbreak Response
4 3. The Safe Food Handler
3.1 How Food Handlers Can Contaminate Food 3.2 Personal Hygiene Program 3.3 Policies for Reporting Illness and Injury
5 4. The Flow of Food: An Introduction
4.1 Hazards in the Flow of Food 4.2 Monitoring Time and Temperature
6 5. The Flow of Food: Purchasing, Receiving, and Storage
5.1 General Purchasing and Receiving Principles 5.2 Storing Food Safely
7 6. The Flow of Food: Preparation
6.1 Preparation Best Practices 6.2 Cooking Food to Safe Temperatures 6.3 Cooling and Reheating Food
8 7. The Flow of Food: Service
7.1 Holding Food for Service 7.2 Serving Food Safely
9 8. Food Safety Management Systems
8.1 Active Managerial Control and HACCP
10 9. Safe Facilities and Pest Management
9.1 Interior Design and Equipment Requirements 9.2 Utilities and Emergency Planning 9.3 Pest Management
11 10. Cleaning and Sanitizing
10.1 Cleaning and Sanitizing Principles 10.2 Chemical Sanitizers - CRITICAL! 10.3 Dishwashing 10.4 Facility Cleaning
10.3 Dishwashing
Key Takeaways Explain This Topic AI
Manual dishwashing uses five steps: scrape, wash (110°F+), rinse, sanitize (per Section 10.2), air-dry
High-temperature machines sanitize at 180°F final rinse (or 165°F stationary alternative)
Never towel-dry food-contact surfaces—always air-dry on a clean rack
Never rinse after sanitizing—this removes the sanitizer and recontaminates
- Store clean items 6 inches off floor; cups upside down; flatware handles facing up
- Last updated: January 2026
Dishwashing—the process of cleaning and sanitizing dishes, utensils, and food-contact equipment—is one of the most critical food safety tasks. Improper dishwashing allows pathogens to transfer from one surface to food, causing foodborne illness.
Manual Dishwashing (Three-Compartment Sink)
Manual dishwashing in a three-compartment sink (also called three-basin dishwashing) is the standard method when machine washing is not available.
Equipment Needed:
- Three separate basins or compartments
- Hot water heater (for wash water at 110°F+)
- Thermometer to verify water temperature
- Drain boards (clean, sanitized)
- Clock with second hand (for sanitizer contact time)
- Test kit for sanitizer verification
Step-by-Step Manual Dishwashing Process:
- Scrape or remove food - Use a rubber spatula or scraper to remove dried food and debris
- Do NOT soak items first (this delays the process)
- Remove all visible food particles
- Work quickly to prevent cross-contamination
- Wash in Basin 1 - Hot water (110°F+) with detergent
- Use a clean wash cloth or brush
- Scrub all surfaces (top, bottom, inside, outside)
- Pay special attention to crevices where bacteria hide
- Change wash water when suds disappear
- Never reuse dirty wash water
- Rinse in Basin 2 - Clean running water
- Dip or spray items with fresh water
- Remove all soap and detergent residue
- Soap residue can interfere with sanitizer effectiveness
- Items must be visibly clean before moving to Basin 3
- Sanitize in Basin 3 - Correct concentration, temperature, and contact time
- Time based on your sanitizer (7 seconds for chlorine, 30 for iodine/quats)
- Keep items submerged for minimum contact time
- Use a test kit to verify concentration
- Verify water temperature meets sanitizer requirements
- Air-dry - Clean, sanitized drying rack
- Place items upside down
- Never towel-dry (towels recontaminate surfaces)
- Allow to air-dry completely before storage
- Never stack items while wet
Critical Points for Manual Dishwashing:
- Never skip any step - Cutting corners puts food safety at risk
- Never rinse after sanitizing - This removes the sanitizer and recontaminates surfaces
- Never use dirty towels - Causes recontamination
- Never overload basins - Items must have full contact with water
- Never let sanitizer sit unused - It loses strength over time
- High-Temperature Machine Dishwashing
Machine dishwashing uses heat instead of chemicals to sanitize. This is faster and more reliable than manual washing.
High-Temperature Machine Requirements:
- Final rinse water: Must reach a minimum of $180°F$ (82°C) to sanitize
- Contact time: Items must be exposed to 180°F water for sanitization
- Temperature verification: Use a surface thermometer to verify machine reaches proper temperature
Alternative if 180°F not achievable:
- If machine cannot reach 180°F, use a stationary rack and maintain 165°F (74°C) for 1 minute
- Verify temperature with thermometer
High-Temperature Machine Steps:
- Scrape and pre-rinse - Remove all food particles and debris before loading
- Use a rubber scraper
- Rinse with water to remove loose food
- Heavy food residue will not come off in the machine
- Load racks properly - Ensure all items contact water jets
- Do not overload (items must contact water)
- Place items to maximize water flow
- Separate silverware (don't nest—prevents water contact)
- Stack plates vertically or at an angle
- Run the cycle - Machine automatically washes, rinses, and sanitizes
- Temperatures are monitored by the machine
- No manual sanitizer testing required
- Cycle typically takes 1-3 minutes
- Air-dry - Items dry naturally from heat
- Do NOT towel-dry
- Items are hot and will dry quickly
- Handle carefully (items are hot)
Advantages of High-Temperature Machines:
- Faster (1-3 minutes vs. 5-10 minutes manual)
- More reliable (consistent temperatures)
- Less labor-intensive
- Sanitizes at 180°F (guaranteed)
- No chemical sanitizer testing needed
- Chemical Machine Dishwashing
Some operations use chemical machines instead of high-temperature machines. These spray hot water with injected chemical sanitizers.
Chemical Machine Requirements:
- Water temperature: 120°F minimum (much lower than high-temperature)
- Chemical sanitizer: Injected automatically by machine
- Manufacturer instructions: Must be followed exactly for this specific machine
Chemical Machine Steps:
- Scrape and pre-rinse (same as high-temperature)
- Load racks with proper spacing
- Close and run machine cycle
- Machine injects chemical sanitizer
- Air-dry naturally
Important: Always follow your specific machine's manufacturer instructions—chemical machines vary widely.
Storage After Dishwashing
Proper storage prevents recontamination:
- Requirement Details
- Location Store at least 6 inches off the floor on a clean, sanitized shelf
- Container Use clean, sanitized containers; never reuse dirty containers
- Cups & Glasses Store upside down to prevent dust and debris from settling inside
- Flatware Store handles facing upward to prevent hand-contact surfaces from being touched
- Stacking Stack carefully to prevent chips or cracks that create harbors for bacteria
- Protection Cover stored items with a clean cloth or store in cabinets to prevent dust
Never:
- Store items in open areas exposed to dust, pests, or contamination
- Reuse items from the washing rack without drying
- Handle clean items by food-contact surfaces
- Store clean items above raw foods (cross-contamination risk)
- Comparison: Manual vs. Machine Dishwashing
- Factor Manual (3-Compartment) High-Temp Machine Chemical Machine
- Time per item 5-10 minutes 1-3 minutes 2-5 minutes
- Temperature required Per sanitizer (68-100°F+) 180°F final rinse 120°F + chemicals
- Contact time 7-30 seconds (sanitizer dependent) Automatic in cycle Automatic in cycle
- Labor intensity High Low Low
- Consistency Variable (human factor) Consistent (machine) Consistent (machine)
- Cost Low equipment cost High equipment cost Medium equipment cost
- Best for Small operations, limited space High-volume operations Medium operations
- Key Points on Towel-Drying (THIS IS TESTED!)
NEVER TOWEL-DRY food-contact surfaces after sanitizing. This is one of the most common violations cited by health inspectors.
Why towel-drying is dangerous:
- Towels harbor bacteria (E. coli, Salmonella, Norovirus)
- Even "clean" towels have pathogens
- Towel-drying recontaminates sanitized surfaces
- Pathogens immediately begin multiplying on the wet surface
The only acceptable drying method is air-drying on a clean, sanitized rack or shelf.
Dishwashing Chemicals and Safety
Detergents used in Basin 1:
- Must be food-safe and approved for use in food service
- Follow manufacturer dilution instructions exactly
- Store safely away from food and prep areas
- Never mix detergents unless approved
Sanitizers used in Basin 3:
- See Section 10.2 for specific requirements
- Must match three-compartment sink sanitizer (chlorine, iodine, or quat)
- Test concentration regularly
- Replace frequently to maintain effectiveness