Sanitation Tips for Small-Scale Cheese Plants

Good sanitation is critical for producing safe, high-quality cheese. Sanitation practices are mandated by the FDA Food Safety Modernization Act (FSMA) (U.S. Food and Drug Administration, 2015a), which requires that:

• Personnel are properly trained in the principles of food safety and food hygiene, including employee health and personal hygiene
• Personnel are properly trained in the cleaning and sanitation procedures that apply to their job responsibilities
• Overall plant sanitation is under the supervision of one or more qualified individuals
• Facilities must be maintained in a clean and sanitary condition to prevent food from being adulterated
• All food contact surfaces, non-food contact surfaces, equipment, and utensils must be cleaned as necessary to prevent food contamination and allergen cross-contact

Sanitation is everyone's concern. Management needs to be fully committed to ensuring their facilities are sanitary and personnel are following best practices to keep food safe.

How Do I Plan for Hygiene?

Cheesemaking plants should be designed with hygiene in mind. No amount of cleaning alone can make up for poor design and maintenance.

Facilities

Facility construction and traffic flow are the first lines of defense to protect the cheese plant environment from serving as a source of contamination.

Good construction practices include:

• Floors and walls should be constructed of durable, easy-to-clean materials, such as good-quality concrete, dairy brick, or tile
• Floor-wall junctures should be curved (coved) to prevent corners where bacteria can accumulate
• Floors should be sloped to allow water and whey to drain without pooling
• Drains should be designed so they are easy to clean and have the capacity for proper drainage
• Lighting should be sufficient to allow for inspection to identify soiled or damaged areas

Cracks in walls and floors and poorly designed or functioning drains can hide unwanted bacteria and be difficult to clean. Therefore, facilities should be inspected regularly and repaired in a timely manner.

More information on proper construction requirements can be found in the <>Code of Federal Regulations, Good Manufacturing Practices for Sanitary Facilities and Controls (U.S. Food and Drug Administration, 2015b) and the Grade "A" Pasteurized Milk Ordinance (U.S. Food and Drug Administration, 2019).

Contamination can occur when the traffic flow of incoming materials and personnel is not well managed. The concept of hygienic zoning is used to separate areas of the plant based on the risk of contamination to the finished products. Zones can be separated using physical barriers, controlled transitions, and/or sanitary practices, such as:

• Physical barriers: walls, doors, including double or swinging doors
• Controlled transitions: foot baths, floor foamers, hand washing, and sanitizing stations
• Sanitary practices: hand washing and sanitizing, area-specific shoes/boots, uniforms, aprons, and other personal protective equipment (PPE) such as disposable lab coats for visitors

Figure 1 shows an example hygienic zone map for a small-scale cheese plant, illustrating these features and practices:

Raw Product Areas

• Incoming tankers and raw milk storage are separated from the rest of the plant by walls and closed doors
• Controlled transitions (foot bath/floor foamer) between rooms and the hallway

Basic GMP Areas

• Hair and beard nets
• Clean, plant-specific clothes and shoes
• Hands are washed and sanitized upon entering the area

Primary Control Areas

• Processing areas are separated from the rest of the plant by walls and closed doors
• Controlled transitions (foot bath/ floor foamer) into Primary Control Areas
• All personnel follow the requirements for Basic GMP Areas (hair and beard nets, wash and sanitize hands, plant-specific clothes and shoes)
• May require additional area-specific clothes and PPE

Ready-to-Eat Areas

• Ready-to-Eat packaging areas are separated from the rest of the plant by walls and closed doors
• Controlled transition areas (foot bath/floor foamer) into Ready-to-Eat Areas
• All personnel follow the requirements for Basic GMP Areas (hair and beard nets, wash and sanitize hands, plant-specific clothes and shoes)
• Use of clean aprons or other uniforms specific for packaging operations

Non-manufacturing Areas

• All personnel wash hands after eating or using the toilet

Figure 1. Example hygienic zone map for a small-scale cheese plant.

 

 

For facilities producing cheeses made with unpasteurized milk, areas where milk is received and stored should be treated as high-risk zones. Sanitation in milk receiving areas is an important hurdle in managing the risk of contamination to the rest of the facility.

Traffic flow of materials and personnel should prevent cross-contamination between zones. This is accomplished when product flows from raw to primary control areas and finally to ready-to-eat areas. Personnel should move in the opposite direction – from areas of high sanitation to less controlled areas. The following scenarios, based on Figure 1, illustrate good hygienic zoning practices:

• After receiving raw milk, the cheesemaker walks through a foot bath, changes into plant-specific boots in the hallway, and washes her hands. She then goes into the locker room to put on a clean lab coat and other appropriate attire. She puts on a hair net, walks through a foot bath inside the cheesemaking room, and immediately washes and sanitizes her hands before touching anything in the cheesemaking room.

• A supervisor performing a GMP walk-through of the plant starts at the end of the process and works backward. She begins in the locker room by changing into appropriate attire. She walks through the footbath inside the cheesemaking room and immediately washes and sanitizes her hands. She goes to the packaging room and rewashes and sanitizes her hands to avoid any cross-contamination from door handles. She begins her GMP inspection in the packaging room and follows the cheesemaking process backwards through the aging rooms, storage areas, cheesemaking room, and finishes in the raw materials loading bay.

Equipment

Equipment and utensils are made from food-grade, durable materials (such as stainless steel, food-safe plastic, or rubber) and must be constructed with sanitary design principles in mind so that every surface is cleanable. More information about sanitary design, construction, and maintenance requirements for equipment and utensils for food manufacturing can be found in the Code of Federal Regulations on Good Manufacturing Practices Equipment and Utensils (U.S. Food and Drug Administration, 2015c), and from the 3A Sanitary Standards organization.

Avoid creating difficult-to-clean areas when installing equipment. Equipment that is too close to floors, walls, or drains can trap soil, bacteria, and moisture. Equipment should be easily movable, sealed to the ground, or elevated at least 6 inches above the floor.

When equipment surfaces become dented, scratched, or rusted soil and bacteria can accumulate in these areas. Equipment should be inspected routinely and repaired according to the plant's preventive maintenance program. A written preventive maintenance program describes the methods and frequency for checking equipment to make sure that it is working properly and in good repair. Preventive maintenance programs usually consist of multiple documents that describe what needs to be inspected daily, monthly, quarterly, annually, or at some other regular frequency. Detailed standard operating procedures (SOPs) provide directions on how to conduct the inspection, problems to look for, parts that need to be replaced regularly and how often, and what to do if damage is discovered.

Examples of items to be included in a preventive maintenance program for a small-scale cheesemaker are:

Facilities and major equipment

• Refrigerators and freezers
• Refrigerated holding tanks
• Pasteurizers
• Cheese vats
• Cheese presses
• Brine tanks
• Vacuum packagers
• HVAC units
• Pumps
• Clean-in-Place (CIP) and Clean-out-of-Place (COP) units

Utensils and supplies

• Pipe fittings and gaskets
• Filters and screens
• Cheese knives
• Plastic paddles, scoops, and other utensils
• Cheese hoops and molds
• Cheese aging boards
• Shelving and racks
• Tables and carts

Analytical

• pH meters and probes
• Thermometers
• Scales/balances

When possible, refer to the manufacturer's cleaning and maintenance instructions for suggested inspection frequency and protocols.

Personnel

All employees should receive training on personal hygiene and basic sanitary practices relevant to their positions when they are hired, and periodically afterward. Management should document all training, including the person trained, subject matter, and date.

Here are some ways that management can support employee best practices for personal hygiene:

Handwashing and sanitizing

Train personnel:

• When to wash
• How to wash

Provide adequate supplies:

• Handwashing sinks that are clean, accessible, and stocked with soap
• Warm, running water
• Single-use towels or a sanitary hand-drying system
• Hand sanitizer

Proper clothing

Train personnel:

• Clothing worn in cheese processing areas should not be worn elsewhere to prevent cross-contamination.
• Plant boots should never be worn outside the plant and should be cleaned regularly.

Provide supplies:

• Clean uniforms, lab coats, aprons
• Hair and beard nets
• Gloves
• Other PPE as needed

Clothing used in processing areas should be laundered separately, using wash and dry cycles that kill bacteria.

Disease control

Train personnel:

• Employees should not come to work if sick, particularly if vomiting or have diarrhea
• Open wounds should be covered to prevent contamination, and employees should stay out of production areas

Have a disease control policy: 

• Clearly establish non-processing jobs employees can do if they must work while sick or with covered injuries

Have a contingency plan for preventing the spread of infectious illnesses

• Include procedures for managing employee absences and staffing issues
• For management resources regarding COVID-19, see Food Safety and the Coronavirus Disease 2019 (FDA, 2020)

Visitor policy

• Have written procedures for visitors to prevent contamination, such as wearing hairnets and proper PPE
• Have a visitor log or sign-in sheet
• Use signage designating areas where visitors are allowed and where visitors are prohibited

What Does a Facility Sanitation Program Look Like?

A comprehensive sanitation program prevents food from becoming contaminated during receiving, processing, packaging, and storage. A sanitation program covers all aspects of keeping the facility, equipment, utensils, and environment cleaned and sanitized, and identifies sanitary procedures for personnel. Cleaning and sanitizing are two concepts that are often used interchangeably, but have very different definitions:

• Cleaning means removing soil from a surface

• Sanitizing means reducing the microbial load of a clean surface

A good sanitation program addresses the following questions and concepts:

• What practices do employees follow to prevent contaminants from being introduced?
• How and when are equipment and utensils cleaned and sanitized?
• How and when is the plant environment cleaned and sanitized?
• What is cleaned daily? Weekly? Monthly? At other frequencies?
• Are existing cleaning and sanitizing procedures being properly followed and documented?
• Are the cleaning and sanitizing procedures and periodic maintenance schedules ensuring that food is made under sanitary conditions?
• What verification procedures and records are used to ensure practices are effective?

A sanitation program uses a combination of written procedures, cleaning activities, observations, tests, and records to schedule, conduct, and track cleaning and sanitizing in a manufacturing facility. Elements of a comprehensive sanitation program may include:

Written Sanitation Standard Operating Procedures (SSOPs)

Procedures that include step-by-step cleaning directions, specify the chemicals, conditions and frequency of cleaning, and the records used to document these actions.

Examples of SSOPs are:

• Equipment and utensil cleaning
• Cheese aging board and rack cleaning
• Use of automated cleaning equipment (e.g., Clean-in-Place (CIP) systems)
• Drain cleaning
• Facility surface cleaning (e.g., walls, light fixtures, vents, condensate pans)

Master sanitation schedule

A schedule that identifies areas and equipment that need to be cleaned on a daily, weekly, monthly, or other periodic basis, including the name of equipment or procedure and a reference to SSOPs, where applicable.

Examples of items that might be included on a Master Sanitation Schedule are:

• Drains
• Foot baths
• Aging racks and boards
• Undersides of equipment
• Brine tanks
• Production and storage area floors and walls
• Walk-in coolers
• Tops of piping and light fixtures
• HVAC units and condensate pans
• Non-production areas (e.g., labs, offices, locker rooms, bathrooms)

Personnel policies

Training Policies:

• Procedures to train employees in their job responsibilities and food safety practices
• Ensure employees have access to written copies of all policies that they are expected to follow

Visitor Policies:

• Identify procedures and practices that are agreed to before visitors are allowed inside manufacturing areas

Sanitation Policies:

• Handwashing
• Dress code or uniforms
• Use of disposable PPE
• Employee training frequency
• Sick leave

Environmental monitoring

Procedures for monitoring the environment for pathogens or indicators to verify that the sanitation program is working. This is particularly important in Ready-to-Eat areas (Figure 1).

Pest management

Pest management can be outsourced to a licensed Pest Control Operator (PCO), but it is still everyone's responsibility to make sure that the plant is pest-free.

Pest reports should be read when they are received, and action should be taken as needed.

Where's the Dirt?

Cleaning frequently focuses on primary food contact surfaces. Non-food-contact surfaces in a small-scale cheese plant are often close to contact surfaces and can cause contamination if particles are blown or sprayed into the air. This is especially true for drains that are located underneath cheese vats. Areas where whey drains for a long time, such as on draining racks or presses, can lead to pooled whey, which is sticky, difficult to clean, and can harbor unwanted bacteria.

The following areas in small-scale cheese plants were found to be prone to sanitation problems (Caprera and Kaylegian, in preparation), with the most problematic areas listed first in each category:

Food-contact surfaces

• Draining racks
• Cheese presses
• Aging room shelves (wood, plastic, metal supports)

Non-food-contact surfaces

• Floor squeegees and brushes
• Drains and drain covers
• Floors (cracked, pitted, poorly sloped)
• Floor/wall junctures
• Undersides of equipment (presses, vats, draining tables, carts, cutting tables, aging room shelves)
• Underneath doors
• Underneath foot baths
• Underneath waste containers
• Equipment and cart wheels

How Do I Deal with Dairy Dirt?

Effective cleaning is tailored to the types of soils being removed, the item being cleaned, and the cleaning method. Cleaning requires mechanical force to remove debris as well as chemicals used in correct concentrations and at the right temperature for the right amount of time.

Dairy Soils

These are the soils found in cheese and dairy plants and how they are removed:

Fats

• Use hot water (above 120°F) and alkaline detergents

Proteins

• Use chlorinated alkaline cleaners, sometimes with added enzymatic or oxidizing agents
• Note that high temperatures (above 160°F) can cause proteins to denature and become harder to remove

Sugars (lactose)

• Will dissolve in warm or hot water used during routine cleaning procedures

Minerals

• Use an acid cleaner

Microorganisms

• Most microorganisms are removed during routine cleaning procedures
• Microorganisms can never be fully removed by cleaning alone, which is why sanitizers are used on clean surfaces

Steps for Cleaning and Sanitizing

There are four basic steps to cleaning and sanitizing:

1.  Pre-rinse

• Warm water is used to remove loose particles

2.  Wash

• Water and detergents are used with mechanical force to loosen and remove stuck-on soils
• Key factors for washing are described by the acronym TACT: Time, Action (mechanical force), Concentration, Temperature

3.  Post-rinse

• Water removes residual cleaners
• Acid rinses can be used to remove minerals

4.  Sanitize

• Sanitizers reduce the number of microorganisms when applied to a clean surface
• Sanitizers can be inactivated by residual soil on a surface

Cleaning Methods

One or more of the following methods are used for cleaning in cheese and dairy plants:

Manual cleaning

• Equipment is disassembled and all parts are washed by hand.
• Utensils are washed by hand.
• Brushes should be segregated by use and stored so that cross-contamination of brushes does not occur.
• Using color-coded brushes is a good sanitary practice.
• White brushes are commonly used for food-contact surfaces
• Yellow or Blue brushes are commonly used for non-food contact surfaces
• Red brushes are commonly used for areas that contact raw milk
• Black blushes are commonly used for drains

Clean-out-of-place (COP) systems

• Equipment is disassembled and parts are washed in a COP tank that uses pumped water to create mechanical force.
• All items must be completely submerged for proper cleaning.
• Time and temperature are controlled and recorded.
• Any parts that do not fit in the COP tank must be washed by hand.

Clean-in-place (CIP) systems

• Equipment is washed without disassembly by recirculation of cleaning and sanitizing solutions. This is common for pasteurizers, transfer lines, and storage tanks.
• CIP systems are set up by a chemical supplier and are specific to a facility based on equipment and plant layout.
• Time and temperature are controlled and recorded.

For more information on cleaning and sanitizing in dairy plants, see Key Concepts of Cleaning and Sanitizing (Kaylegian, 2018) and Guidelines for Cleaning and Sanitizing in Fluid Milk Processing Plants (Dairy Practices Council, 2001).

How Do I Know It's Clean?

Small-scale cheesemakers can use a combination of different techniques to evaluate sanitation effectiveness depending on the area, type of procedures used, plant practices, associated risk, and cost.

Visual Observation

Observations are an effective part of maintaining a clean plant. Visible soil or build-up on equipment is the first indication that there is a problem with sanitation.

All equipment should be inspected before sanitizing at process startup and after cleaning at process end. Observations can be formalized by keeping a detailed log, scheduling time for plant inspections, and taking photographs of equipment, utensils, and grounds that are in and out of compliance for personal reference. Some things to look for:

• Milk, curd, and cheese particles and residues
• Milkstone (a white or yellowish deposit of minerals and other residues from milk)
• Rainbow sheen on stainless steel surfaces and inside of tanks
• Discoloration on walls, floors, equipment, or utensils
• Pooled water or whey that doesn't drain
• Visible mold on walls, floors and equipment
• Cracks or scratches in floors and equipment
• Rust
• Worn or cracked gaskets
• Welding defects
• Dirt or dust
• Trash outside of trash bins (e.g., paper towels, gloves, used or discarded packaging materials)
• Evidence of pests (e.g., insects, rodent droppings)

Testing

While observation is the first line of defense, many hazards cannot be seen by the naked eye. Therefore, additional tests may be used to identify chemical and biological (microbial) hazards. Some tests are quick and can be done in-house by plant personnel, but others need to be sent to the local testing lab. Some test samples may need to be collected by outside lab personnel because proper sampling technique requires additional training and certification.

Here are some of the tests that can be done to support an effective sanitation program:

Chemical concentration tests

• Use for testing detergent and sanitizer strength.
• If a chemical solution is too weak, it will not clean sufficiently.
• If a chemical solution is too stron,g it may pose a chemical hazard.

Microbial indicator testing

These are tests for non-pathogenic microbial families that serve as an indicator of poor sanitation and potential biological hazards.

• Aerobic Plate Count (APC) for total bacteria present (may also be called Standard Plate Count (SPC) or Total Plate Count (TPC))
• Coliforms
• Listeria species

ATP swabs

• ATP (adenosine triphosphate) is a molecule found in all living things and can be used as a marker of biological residues on surfaces.
• ATP swabs can be useful for making sure food contact surfaces are thoroughly cleaned.

Microbial pathogen testing

• These organisms cause foodborne illness and are biological hazards
• Two important organisms to test for are Listeria monocytogenes (this is a follow-up test if the Listeria species indicator test is positive) and Salmonella species
• Pathogen testing should be addressed in an environmental monitoring program.
• Pathogen testing should be conducted by properly trained personnel.

To understand what your test results mean, you must first establish limits. For microbial indicator (non-pathogen) testing and ATP swabs, you will need to establish acceptable and unacceptable baselines through preliminary testing and monitoring over time to determine what is typical for your facility. Limits for some tests, such as pathogen testing, may be "pass/fail", which means that a negative result is acceptable, while any presence may be unacceptable.

What Happens If Sanitation Isn't Effective?

Even with a comprehensive program, breakdowns in sanitation are possible. You may notice problems in sanitation through visual observations or test results. Sanitation problems may also be the root cause of customer complaints or deductions in state and federal plant inspections.

The next steps will depend on the severity and frequency of sanitation problems. Problems detected with food contact surfaces will necessarily be more severe than those from non-contact surfaces. When a sanitation problem first appears, the initial corrections are to:

• Clean again and retest
• Hold, evaluate, and determine the disposition of any potentially contaminated products

If problems continue, some options are:

• Change SSOPs:  adjust cleaning chemicals, concentrations, or temperatures
• Change cleaning frequency
• Retrain employees
• Consult your cleaning chemical supplier or another specialist
• Reevaluate the hygienic zoning and traffic flow patterns of the plant
• Replace or repair equipment and facilities that are difficult to clean. Figure 2 shows an example of repairs made to a floor drain to fix sanitation issues.

Figure 2. Cheese plant make room drain before and after actions taken to fix sanitation problems (image credit: Lisa Caprera).

 

In cases where a sanitation problem may have resulted in a contaminated product, a corrective action is needed. Corrective actions are planned, written procedures to:

• Identify and correct a food safety problem
• Prevent the problem from recurring
• Prevent contaminated food from being sold

All steps taken as part of a corrective action must be documented, as well as the disposition of any potentially contaminated food.

A Few Last Words

Ultimately, plant sanitation is the responsibility of everyone. Using a systematic program to train employees and detail how and when things are cleaned can keep sanitation from falling through the cracks.

Now that you have the dirt on the dirt, don't let a lack of sanitation soil your good name!

Additional Resources

American Cheese Society, (720) 328-2788, Denver, CO

- Best Practices Guide for Cheesemakers, 2nd ed. 2017.

- Safe Cheesemaking Hub

Dairy Practices Council, (419) 890-5147, Pandora, OH

- Guidelines for Cleaning and Sanitizing in Fluid Milk Processing Plants, DPC Guideline 29. 2001.

- Guideline for Food Safety in Farmstead Cheesemaking, DPC Guideline 100. 2002.

Food Safety Preventive Controls Alliance, (312) 567-3000, Bedford Park, IL

- FSPCA Preventive Controls for Human Food Participant Manual, 1st ed. 2016.

Innovation Center for U.S. Dairy, Rosemont, IL

- Control of Listeria Monocytogenes - Guidance for the U.S. Dairy Industry, 2015.

- Controlling Pathogens in Dairy Processing Environments - Guidance for the U.S. Dairy Industry,2019.

Penn State Extension University Park, PA

- Writing Sanitation Standard Operating Procedures (SSOPs), 2016.

- Key Concepts of Cleaning and Sanitizing, 2018.

- Cleaning and Sanitizing Wood Boards for Cheese Aging, 2018.

U.S. Food and Drug Administration, 888-463-6332, Silver Spring, MD

Code of Federal Regulations (CFR) Title 21 Part 117: Current Good Manufacturing Practice, Hazard Analysis, and Risk Based Preventive Controls for Human Food, 2015.

- Control of Listeria monocytogenes in Ready-To-Eat Foods: Guidance for Industry, 2017.

- FDA Food Code, 2017.

- Grade "A" Pasteurized Milk Ordinance,2019.

Bibliography

Caprera, L.C. and K.E. Kaylegian. (In preparation). Identification and tracking of key environmental sites to help small-scale raw milk cheesemakers improve sanitation.

Dairy Practices Council. 2001. Guidelines for Cleaning and Sanitizing in Fluid Milk Processing Plants, DPC Guideline 29. Dairy Practices Council, Pandora, OH.

Kaylegian, K.E. 2018. Key Concepts of Cleaning and Sanitizing, Penn State Extension, University Park, PA.

U.S. Food and Drug Administration. 2015a. Code of Federal Regulations (CFR) Title 21 Part 117: Current Good Manufacturing Practice, Hazard Analysis, and Risk Based Preventive Controls for Human Food.

U.S. Food and Drug Administration. 2015b. Code of Federal Regulations (CFR) Title 21 Part 117.37: Sanitary Facilities and Controls.

U.S. Food and Drug Administration. 2015c. Code of Federal Regulations (CFR) Title 21 Part 117.40: Equipment and Utensils.

U.S. Food and Drug Administration. 2019. Grade "A" Pasteurized Milk Ordinance.

U.S. Food and Drug Administration. 2020. Food Safety and the Coronavirus Disease 2019 (COVID-19)

Contact Us

For more information, comments, or questions, please contact:

Kerry E. Kaylegian, Ph.D.
Associate Research Professor
Department of Food Science
The Pennsylvania State University
814-867-1379, kek14@psu.edu