Dairy Establishment Inspection Manual – Chapter 12 - Batch Pasteurization Tasks

This page is part of the Guidance Document Repository (GDR).

Looking for related documents?
Search for related documents in the Guidance Document Repository

When batch pasteurizers are used to prepare starter cultures the starter vats must meet the conditions within this chapter. In cases where all the ingredients going into the starter vat have been previously pasteurized or have been shown to be phosphatase negative in the case of dry milk products (B.08.030 FDR), for example skim milk powder is added to already pasteurized milk, and the product is being hygienically handled there would not be a requirement for re-pasteurization under this chapter. The mixing vats are to be rated under task 1.15.0.3201 - Starter Preparation.

In the case of ice cream mix, if the milk ingredients going into the mix are pasteurized and all other components being added to the mix are microbiologically safe and ready to eat, then pasteurization of the mix is not required. There would not be a requirement to re-pasteurize and meet the batch pasteurization requirements of this chapter. The establishment must be able to provide documentation to show that the product is safe (e.g. supplier's and processor's specifications and certification papers as per 1.10.02.03; end product testing as per 1.10.07.03). The mixing vats are to be rated under task 1.16.0.3604. In the event that provincial regulations differ from the above and are tighter they must be met.

1.12.01 Batch Pasteurization Records

1.12.01.01 Temperature and Time Requirements

Temperature and time are critical factors required to achieve pasteurization. Failure to achieve pasteurization could result in a microbiological hazard in the dairy product.

The following are the generally accepted pasteurization schedules for dairy products produced by batch pasteurization.

Milk-Based Products - below 10% milk fat (fluid milk, goat milk, whey): 63°C for 30 minutes.

Milk-Based Products - 10% milk fat or higher, or added sugar (fluid cream, cream for butter, chocolate milk, flavoured milk, etc.): 66°C for 30 minutes.

Frozen Dairy Product Mixes, Egg Nog - 69°C for 30 minutes.

In order to convert the above temperatures from Celsius to Fahrenheit use the following formula: °F = (°C x 9/5) + 32

Note: In the event that provincial regulations differ from the above and are tighter they must be met.

Other - Any equivalent time-temperature process reviewed by Health Canada and found to meet the requirements of the Food and Drug Regulation B.08.002.2(1) with respect to the reduction of alkaline phosphatase activity.

Any time-temperature process required under provincial regulations is acceptable.

1.12.01.02 Process Control Records

Process control records should be part of the quality assurance program. This information must be recorded in pen to provide a permanent record. Since this information provides a processing record, it will assist the plant in tracking down quality and safety problems and prevent recall of their products. As these records are the only historical record of exact happenings of the pasteurization of each product it is very important that they adequately and accurately reflect the heating process. It is acceptable for some information that is required on the process control record to be in a separate document, for example a computer print-out as long as there is a cross-reference by production code and/or date between the print-out and the process control record. The process control record must be replaced daily. It is also critical that the operator notes any unusual occurrences, reasons for and time of occurrence. The process control record is the legal record of the pasteurization process. The process control record(s) must be reviewed on a timely basis by a designated person responsible to the plant management. The records must indicate satisfactory follow-up for out of specification findings and the documentation of actions taken.

Process control records for batch pasteurizers shall provide the following data once every twelve hours:

  1. Plant name and address or registration number;
  2. Date, shift and batch number where applicable;
  3. Vat number;
  4. Record of the time of filling and emptying the vat (if applicable) and record of holding period;
  5. Reading of air space thermometer at the start of the holding period at a given time or reference point indicated on the chart and at the end of the holding period;
  6. Recording of indicating thermometer during the holding period at a given time or reference point indicated on the chart. This reading must never be lower than the recording thermometer reading;
  7. Number or location of recorder when more than one is used;
  8. Amount and name of product represented by each batch or run on the chart;
  9. Operator's comments and reasons for all unusual occurrences (including time of occurrence);
  10. Signature or initials of operator.

1.12.01.03 Verification of Temperature and Time

Vat pasteurization was one of the first methods used to process milk. This system requires batch processing relatively small volumes of milk at a specific temperature for a long period of time. In order to insure minimum holding time is achieved, the following must be verified by observing the batch pasteurization cycle and from the pasteurization records:

  1. Required minimum holding time and temperatures (product and air space) must be met.
  2. The holding time starts after the indicating thermometer reading has reached the pasteurization temperature and air space thermometer reads at least 3°C (5°F) higher than the minimum pasteurization temperature required for the product.
  3. When the milk is heated to pasteurization temperature in the vat and is partially cooled in the vat before opening the outlet valve, the process control records must show at least 30 minutes at or above the minimum pasteurization temperature.
  4. When the milk is pre-heated to pasteurization temperature before entering the vat, the process control record must show a holding time of 30 minutes plus the time of filling the vat from the level of the recording thermometer bulb. When cooling is begun after the outlet valve is opened or is done entirely outside the vat, the record must show a holding time of 30 minutes at or above minimum pasteurization temperature plus the time necessary to empty the vat to the level of the recording thermometer bulb.
  5. When the recorded time interval on the process control record at the pasteurization temperature includes filling and/or emptying time, such intervals must be indicated on the record by the operator, by inscribing the holding time on the record.
  6. The filling time and emptying time for each vat so operated must be determined initially and after any change which may affect these times.
  7. No milk or raw product shall be added to the vat after the start-up of the holding period.
  8. The agitation shall be such that the temperature difference between the milk in the centre of the vat and the coldest milk in the vat shall not exceed 0.5°C (1°F) at any time during the holding operation.

1.12.01.04 Retention of Process Control Records

Records shall be retained:

  1. A one year period minimum; or
  2. As determined by the responsible regulatory agency; or
  3. Until the finished product has been consumed (if more than one year).
Batch Pasteurization Records
Table description

This table shows the inspection criteria by task for batch pasteurization records: 1.12.01.01 Temperature and Time Requirements (HS=2); 1.12.01.02 Process Control Records (HS=3); 1.12.01.03 Verification of Temperature and Time (HS=1) et 1.12.01.04 Retention of Process Control Records (HS=3).

Task Inspection Criteria
1.12.01.01 Temperature and Time Requirements (HS=2) A. A representative sampling of plant's records must be assessed
  • Complete records for all products
  • Minimum holding time and minimum temperature required must be met (see text for pasteurization requirements)
1.12.01.02 Process Control Records (HS=3) A. A representative sampling of plant's records must be assessed
  • Processing records provide the following permanent data every 12 hours (if applicable):
    • plant name and address or registration number
    • date, shift and batch number where applicable
    • vat number
    • record of the time of filling and emptying the vat (if applicable)
    • record of holding period
    • reading of airspace thermometer at the start of the holding period at a given time or reference point indicated on the chart and at the end of the holding period
    • reading of indicating thermometer during the holding period at a given time or reference point indicated on the chart. This reading must never be lower than recording thermometer reading.
    • number or location of recorder when more than one is used
    • amount and name of product represented by each batch or run on the chart.
    • record of unusual occurrences (including reasons for and time of occurrence)
    • signature or initials of operator
  • Record is replaced daily
  • Satisfactory follow up for out of specification findings and documentation of actions taken
1.12.01.03 Verification of Temperature and Time (HS=1) A. Pasteurization Evaluation
  • Required minimum holding time and temperatures (product and airspace) must be met.
  • Holding time starts after the indicating thermometer reading has reached the pasteurization temperature and airspace thermometer reads at least 3°C (5°F) higher than the minimum pasteurization temperature
  • Process control record shows at least 30 minutes holding time at minimum pasteurization temperature before opening the outlet valve.
  • When milk is preheated to pasteurization temperature before entering vat, the record shows:
    • holding time of at least 30 minutes at or above the pasteurization temperature and
    • time of filling the vat from the level of the recording thermometer bulb.
  • When cooling is begun after the outlet valve is opened or done outside the vat, the record shows:
    • holding time of at least 30 minutes at or above the pasteurization temperature and
    • time necessary to empty the vat to the level of the recording thermometer bulb.
  • When the recorded time interval on the process control record at pasteurization temperature includes filling and/or emptying time, such intervals be indicated on the record.
  • No milk be added to the vat after the start of the holding period.
  • Proper agitation
    • temperature difference between the milk in the centre of the vat and the coldest milk in the vat not exceed 0.5°C (1°F) at any time during the holding period.
1.12.01.04 Retention of Process Control Records (HS=3) A. Timeframe
  • Minimum of one year period
  • As determined by responsible regulatory agency; or
  • Until the finished product has been consumed (if more than one year)

1.12.02 Batch Pasteurizer

This method of pasteurization still exists in small plants to process fluid milk and in larger plants to manufacture cultured products. Batch pasteurizers require specific design features and auxiliary equipment to ensure that every particle of milk is pasteurized.

1.12.02.01 General Conditions

Milk is heated in the vat to desired temperature by means of hot water either sprayed on the sides of the vat or circulated around the double jacket or by means of heating coils surrounding the inner jacket.

A single-or two-speed agitator, and a vertical baffle plate inside the vat are used to create efficient agitation for proper heat transfer. Effective agitation reduces the chance of burn-on on the inside wall. The agitator must be operating during pasteurization.

The exterior and interior of the vat must be constructed of stainless steel, be clean and in good mechanical condition. The bottom of the vat should be sloped to permit free drainage. Sanitary seals, coils, and valves must be examined to determine if they are being removed and cleaned daily.

1.12.02.02 Inlet and Outlet Valves and Connections

Valves used on vat pasteurizers must meet the following two conditions:

  1. Vat outlet valve is close coupled. A close-coupled valve is a valve, the seat of which is either flush with the inner wall of the pasteurizer or so closely coupled that no milk or milk product in the valve is more than 0.5°C (1°F) colder than the milk or milk product at the centre of the pasteurizer at any time during the holding period. A close-coupled valve, which is not truly flush, is considered as satisfying this requirement when:
    1. The vat outlet is so flared that the smallest diameter of the large end of the flare is not less than the diameter of the outlet line plus the depth of the flare; and
    2. The greatest distance from the valve seat to the small end of the flare is no greater than the diameter of the outlet line; and
    3. The outlet and the agitator are so placed as to insure that milk current will be swept into the outlet.
  2. Vat outlet valve has a leak-protection mechanism to prevent the contamination of pasteurized product surfaces including the valve outlet connection. A leak-protector valve is a valve provided with a leak-detecting device, which when the valve is in any closed position, will prevent (redirect) leakage of milk or milk product past the valve.

    Currently, only manual valves and the automatic valve system described below meet these criteria. Any other types of valves systems must be assessed and accepted by the CFIA, on a case-by-case basis, in order to be rated as satisfactory.

    For Air Operated (Automatic) Valve systems:

    Note: Air operated (automatic) valve systems are considered acceptable to separate raw and pasteurized products only on the outlet line of a vat pasteurizer. Use of this valve system to separate raw and pasteurized product elsewhere in the system is not permitted as indicated in Appendix 19–10 (Preventing Cross Connections in Dairy Plants).

    1. The valve used must be a double seat mix-proof valve which has two seats (on separate stems) with a leakage chamber (vent or leak port) between them. The leakage chamber must be vented to the atmosphere with a leak detect tube having a hydraulic diameter greater than the hydraulic diameter of the supply. The leak detect vent must always be fully open to the atmosphere with no restrictions and the valves must be installed such that a leak can be observed. The valve's fail safe position is defined as closed.
    2. Plant management, in conjunction with their valve supplier/manufacturer must ensure that valves used in their system meet the requirements of Appendix 10. This must be demonstrated to the CFIA through testing, validation and proper documentation.
    3. The valve must use at least one micro-switch or other sensor to signal that it is closed (inactivated position) prior to beginning the legal holding period required for pasteurization of the product in the vat. The valve must be closed (inactivated position) for the entire legal holding period required to complete the pasteurizing of the product in the vat.
    4. The leak detector chamber and vent must be designed and operated to be pasteurized by flushing with culinary steam and to be cleaned and sanitized by CIP. The steam must reach all points within the leak detector chamber so that all internal portions of the chamber reach the minimum pasteurization time/temperature for the product being processed. The leak detector chamber and vent must be equipped with an air space indicating thermometer.
    5. The minimum time requirement for the steam pasteurization of the leak detector chamber cannot be started until the minimum time/temperature requirement for pasteurization of the product in the vat has been completed.
    6. The vat pasteurizer and the outlet valve must be interlocked so that the outlet valve remains closed throughout the pasteurization of the product in the vat and the steam pasteurization of the leak detection chamber.

    For plug-type outlet valves:

    1. To prevent clogging and promote drainage plug-type outlet valves must have leak-protector grooves at least 0.5 cm (3/16 inch) wide and 0.25 cm (3/32 inch) deep at the centre. The valves shall be installed in the proper position to insure the function of the leak protector grooves and the drainage of the leak-detector valve.
    2. Plug-type outlet valves must be provided with stops on the plug (to guide the operator in closing the valve so that unpasteurized milk or milk product may not inadvertently be permitted to enter the outlet line). The stop shall be designed so that the plug will be irreversible when the plug is provided with any grooves or their equivalent, unless duplicate, diametrically opposite grooves are also provided. Stops shall be designed so that the operator cannot turn the valve beyond the stop position, either by raising the plug or by any other means.

Note: Butterfly valves do not meet the above criteria and are therefore not acceptable.

When assessing the valves and connections of a vat pasteurizer please note the following requirements (see Appendix 19-7):

  1. Outlet valves, in addition to the requirements listed above, i.e. close-coupled and leak-protection, shall be designed so as to prevent the accumulation of unpasteurized milk or milk product in the milk or milk product passages of the valve when the valve is in the closed position (the position of the valve seat that stops the flow of milk into and out of the pasteurizer). During the heating or holding step, milk in this passage may not reach pasteurization temperature and when the valve is re-opened this unpasteurized milk would contaminate the pasteurized product surfaces.
  2. Inlet connections must not enter the pasteurizer below the level of milk.
  3. When the inlet line enters the vat above the milk level and is submerged in the milk, the inlet line must be provided with an automatic air-relief or vent located at the valve or by drilling a hole at least 0.32 cm (1/8 inch) in the diameter in the fill pipe, below the vat cover, but above the maximum milk level.
  4. Inlet valves must not be located in the vertical pipeline.
  5. Pipeline between the inlet valve and vat must be sloped to assure free drainage.
  6. Close-coupled vat outlet valve bodies and plugs shall be made of stainless steel or of other materials that have heat transfer properties at least equal to stainless steel.
  7. Milk inlet piping shall be removed from the vat during pasteurization, holding, cooling and emptying.
  8. On systems using a plug type outlet valve on the vat pasteurizer, the pasteurized milk outlet piping shall be removed at the outlet valve during vat filling, heating and holding.

1.12.02.03 Cover (Ports)

Covers must be constructed so as to prevent the entrance of surface drainage. This shall be accomplished with all openings being protected by raised edges and overlapping edges on the cover. Condensate-diverting aprons, if used are located as close to the vat as possible and on all pipes, thermometers and other equipment extending into the vat. These are not required if a water-tight joint is used. The cover must be kept closed during operation to assure proper pasteurization of the air space during the holding time.

1.12.02.04 Air Space Heating

Air space heating can be achieved by using an elevated pasteurization temperature or using an air space heater. This task will rate either the air space heater or the higher pasteurization temperature.

Each batch pasteurization vat which is operated at the minimum pasteurization temperature must be equipped with an air space heater using culinary steam and an air space indicating thermometer.

If the air space temperature is at 3°C (5°F) or more above the minimum pasteurization temperature, the air space heater is not required, but the air space indicating thermometer is necessary.

Batch Pasteurizer
Table description

This table shows the inspection criteria by task for batch pasteurization 1.12.02.01 General Conditions (HS=3); 1.12.02.02 Inlet/Outlet Valves and Connections (HS=2); 1.12.02.03 Cover (Ports) (HS=3) et 1.12.02.04 Air Space Heating (HS=2).

Task Inspection Criteria
1.12.02.01 General Conditions (HS=3) A. General Inspection Criteria for Dairy Plant Equipment
B. Specific Areas of Interest
  • Clean and in good condition
    • sanitary seals, coils, valves
  • Bottom sloped permitting free drainage
  • Agitator present and operating during processing
1.12.02.02 Inlet/Outlet Valves and Connections (HS=2) A. Inlet and Outlet Valves
  • Valves must meet the following two conditions
    • close-coupled
    • leak protection
  • For plug-type outlet valves:
    • must have leak protector grooves at least 0.5 cm (3/16 inch) wide and at least 0.25 cm (3/32 inch) deep at the centre (verified from the plant documentation)
    • Stops provided on the plug of the valves
  • Inlet valves not located in vertical pipeline
  • Outlet valve bodies and plugs shall be made of stainless steel or of materials with heat transfer properties equal to stainless steel
  • Outlet valve design prevents accumulation of unpasteurized milk in the valve passages of the valve
  • For air operated (automatic) valve systems see criteria on the adjoining page

B. Connections

  • Inlet connections do not enter the pasteurizer below the level of the milk
  • When inlet line enters above the milk level and is submerged in milk, then the line must be:
    • provided with an automatic air relief, or;
    • a vent located at the valve, or;
    • have a hole (at least 0.32 cm (1/8") diameter) drilled in the fill pipe below the vat cover, but above maximum milk level
  • Milk inlet piping removed from the vat during pasteurization, holding, cooling and emptying
  • Pasteurized milk outlet piping removed at the outlet valve during vat filling, heating and holding (on systems using a plug type outlet valve)
  • Sloped pipeline between inlet valve and vat to assure free drainage
1.12.02.03 Cover (Ports) (HS=3) A. Requirements
  • Valves must meet the following two conditions
  • All openings protected by raised edges
  • Overlapping edges on the cover
  • Condensate - diverting aprons:
    • as close to the vat as possible
    • on all pipes, thermometers and other equipment extending into the vat
    • not required if water-tight joint is used
  • Closed during operation
1.12.02.04 Air Space Heating (HS=2) A. Airspace Heating During Holding Period:
  • By using elevated pasteurization temperature
  • By airspace heater
    • using culinary steam with proper culinary steam injection system

1.12.03 Indicating Thermometer (Batch Pasteurization)

Indicating thermometers on batch pasteurizers provide the official processing temperature of the product.

1.12.03.01 General Conditions

This thermometer is required on all batch pasteurizers. It shall be of sanitary design, mercury actuated, direct reading, no column splitting and contained in a corrosion resistant case which permits easy observation of column and scale. The filling above the mercury is to be nitrogen or an equally suitable gas. The thermometer must be protected against elevated temperatures used during cleaning and sanitizing cycles. The bulb shall be Corning normal or equivalent. Batch indicating thermometers may be long stemmed and inserted directly into the product or inserted into a projectile well located in the side of the vat.

Types other than mercury actuated (e.g. resistance temperature devices (RTD) may be used if they are documented to be equally fail-safe, accurate, reliable, and meet the scale specifications. The criteria in Appendix 19-13: Design Requirements for Digital Thermometers shall be used to evaluate RTDs when used as alternatives to mercury actuated direct reading thermometers.

1.12.03.02 Specifications

The mercury column width shall be magnified to an apparent width of at least 1.6 mm (.0625 inch). The scale shall have a span of at least 14°C (25°F) including the pasteurization temperature +/- 3°C (5°F), graduated in 0.5°C (1°F) divisions. On batch pasteurizers used solely for thirty (30) minute pasteurization of milk and milk products above 72°C, indicating thermometers with 1°C (2°F) scale graduations, with not more than six (6) Celsius degrees (eleven (11) Fahrenheit degrees) per 2.54 centimetres (1 inch) of scale can be used. Indicating thermometer must be in the same unit of measure as the recording thermometer, either both are Celsius or both are Fahrenheit.

1.12.03.03 Calibration / Records

The thermometer shall be accurate to within +/- 0.25°C (0.5°F) throughout the specified scale range and shall be calibrated upon installation and at least every 6 months thereafter using a thermometer of known accuracy.

Records of tests performed to determine the thermometer's calibration shall be maintained in the plant's files. The frequency of testing should be increased if the calibration is consistently found to be out of adjustment. If the calibration is consistently found to be out of adjustment, the reason for the calibration problems should be immediately identified and rectified.

Testing methods shall comply with the required standards, and must show satisfactory follow-up on out of specification findings. Plant management must investigate the safety of the product produced with out of calibration equipment (e.g. if the indicating thermometer is reading higher than the calibration standard, the product may have been under processed).

Indicating Thermometer (Batch Pasteurization)
Table description

This table shows the inspection criteria by task for Indicating Thermometer (Batch Pasteurization): 1.12.03.01 General Conditions (HS=2), 1.12.03.02 Specifications (HS=2); et 1.12.03.03 Calibration/ Records (HS=1).

Task Inspection Criteria
1.12.03.01 General Conditions (HS=2) A. Requirements
  • Clean and in good condition
    1. Mercury Type
      • Direct reading
      • No column splitting
      • Easy to read
      • Contained in a corrosion resistant case
      • Protected against elevated temperatures used during cleaning and sanitation cycle
      • May be long stemmed and inserted directly into the product or inserted into a well located in the side of the vat
    2. Resistance Temperature Devices (R.T.D.)
      • Accurate, fail-safe, reliable and meets scale specifications
      • Meets the design requirements in Appendix 19-13
      • Does not have to be dual-type
1.12.03.02 Specifications (HS=2) A. Requirements
  • Column width magnified to an apparent width of at least 1.6 mm (0.0625")
  • Scale span of at least 14°C (25°F) including pasteurization temperature +/- 3°C (5°F)
  • Graduated in 0.5°C (1°F) divisions; graduated in 1°C (2°F) when  pasteurizers used solely for 30 minute pasteurization at temperatures above 72°C (161°F)
  • Same unit of measure as the recording thermometer
1.12.03.03 Calibration / Records (HS=1) A. Calibration
  • Temperature accuracy within +/- 0.25°C (0.5°F)
  • Frequency of calibration (upon installation and at least once every 6 months)
  • Tests completed according to required methods and standards

B. Records

  • Available; easily accessible
  • Satisfactory follow up on out of specification findings and documentation of actions taken
    • product safety assessment required

1.12.04 Indicating thermometer (air space)

An air space indicating thermometer is necessary in all batch pasteurization vats to ensure a temperature of at least 3°C (5°F) higher than the required minimum pasteurization temperature in the air space above the milk. This will guarantee that every particle of milk, including the surface will receive the necessary heat treatment.

1.12.04.01 General Conditions

An air space indicating thermometer shall be of sanitary design, mercury actuated, direct reading, contained in a corrosion resistant case which permits easy observation of column and scale. The filling above the mercury is to be nitrogen or an equally suitable gas. The thermometer must be protected against elevated temperatures used during cleaning and sanitizing cycles. The bulb shall be Corning normal or equivalent. The thermometer bulb shall not be submerged in the product.

Types other than mercury actuated (e.g. resistance temperature devices (RTD) may be used if they are documented to be equally fail-safe, accurate, reliable, and meet the scale specifications. The criteria in Appendix 19-13 - Design Requirements for Digital Thermometers shall be used to evaluate RTDs when used as alternatives to mercury actuated direct reading thermometers.

1.12.04.02 Specifications

The bulb chamber should not sit less than 5 cm (2 inches), and not more than 8.75 cm (3.5 inches) below the underside of the cover and should be at least 2.5 cm (1 inch) above the product level. The scale shall have a span of at least 14°C (25°F) including the pasteurization temperature +/- 3°C (5°F), graduated in 1°C (2°F) divisions. The air space thermometer can be in a different unit of measure from the indicating and recording thermometers as long as the temperature requirements are met and the operator knows the temperature conversion.

1.12.04.03 Calibration / Records

The thermometer shall be accurate to within +/- 0.5°C (1°F) throughout the specified scale range and shall be calibrated upon installation and at least every 6 months thereafter using a thermometer of known accuracy.

Records of tests performed to determine the thermometer's calibration shall be maintained in the plant's files. The frequency of testing should be increased if the calibration is consistently found to be out of adjustment. If the calibration is consistently found to be out of adjustment, the reason for the calibration problems should be immediately identified and rectified.

Testing methods shall comply with the required standards, and must show satisfactory follow-up on out of specification findings. Plant management must investigate the safety of the product produced with out of calibration equipment (e.g. if the air space indicating thermometer is reading higher than the calibration standard, the product may have been under processed).

Indicating Thermometer (Air Space)
Table description

This table shows the inspection criteria by task for Indicating Thermometer (Air Space): 1.12.04.01 General Conditions (HS=2); 1.12.04.02 Specifications (HS=2); and 1.12.04.03 Calibration/ Records (HS=1).

Task Inspection Criteria
1.12.04.01 General Conditions (HS=2) A. Requirements
  • Clean and in good condition
    1. Mercury Type
      • Direct reading
      • No column splitting
      • Easy to read
      • Contained in a corrosion resistant case
      • Protected against elevated temperatures used during cleaning and sanitation cycle
      • May be long stemmed and inserted directly into the product or inserted into a well located in the side of the vat
    2. Resistance Temperature Devices (R.T.D.)
      • Accurate, fail-safe, reliable and meets scale specifications
      • Meets the design requirements in Appendix 19-13
      • Does not have to be dual-type
1.12.04.02 Specifications (HS=2) A. Requirements
  • Bulb chamber sit not less than 5 cm (2") and not more than 8.75 cm (3.5") below the underside of cover
  • Bulb chamber be at least 2.5 cm (1") above the product level
  • Scale span of at least 14°C (25°F) including pasteurization temperature +/- 3°C (5°F)
  • Graduated in 1°C (2°F) divisions
1.12.04.03 Calibration / Records(HS=1) A. Calibration
  • Accuracy within +/- 0.5°C (1°F)
  • Frequency of calibration (upon installation and at least once every 6 months)
  • Tests completed according to required methods and standards

B. Records

  • Available; easily accessible
  • Satisfactory follow up on out of specification findings and documentation of actions taken
    • product safety assessment required

1.12.05 Recording Thermometer (Batch)

This is the instrument that automatically records the temperature of the product on a chart that also indicates the time of day thus providing a record of the process and processing time.

1.12.05.01 General Conditions

The recording thermometer unit shall be clean and in good mechanical condition. It should be moisture-proof under normal operating conditions, spring-or electrically-operated and protected against damage at 105°C. The chart positive drive mechanism shall be equipped with a system to prevent slippage and manual rotation (e.g. pin to puncture chart paper). It must also be equipped to produce a continuous permanent record of all pertinent information (i.e. time of day and temperature). The unit should be serviced at least once a year and records of servicing are on file.

1.12.05.02 Recording Pen

The recording thermometer must have a functioning temperature recording pen. There should be an easily accessible adjustment screw on the pen arm enabling the operator to adjust the pen reading to coincide with that of the indicating thermometer. Thickness of the recording pen must not be greater than 0.7 mm (0.025 inch). The recording pen arm must follow the reference arc which is etched on the recorder casing.

1.12.05.03 Sensor Location

Each vat must be equipped with an indicating and a recording thermometer. Double RTD sensors are permitted, one to indicating and one to recording thermometer. The recording and indicating thermometer bulbs should accurately monitor the processing temperature. The recording and indicating thermometer sensors / bulbs should sit as close as possible to each other. Sensors of both the indicating and recording thermometers must be submerged in the product being processed.

1.12.05.04 Chart Specifications

Recording thermometer must be in the same unit of measure as the indicating thermometer, either both are Celsius or both are Fahrenheit.

(A) Batch Pasteurizers with temperatures above 72°C.

Recording thermometers shall use charts graduated in temperature scale divisions of 1C (2°F), spaced not less than 1mm (0.040 inch) apart between 65°C and 77°C, including pasteurization temperature, plus or minus 3°C (5°F), graduated in time scale divisions of not more than 15 minutes. A circular chart shall make one revolution in not more than 24 hours.

(B) Batch Pasteurizers with temperatures below 72°C

Recording thermometers shall use charts graduated in temperature scale divisions of 0.5°C (1°F), spaced not less than 1.6 mm (0.0625 inch) apart between 60°C and 69°C, including pasteurization temperature, plus or minus 3°C (5°F), graduated in time scale divisions of not more than 10 minutes. If the ink line is thin enough to distinguish it from the chart line, the temperature scale divisions of 0.5°C (1°F) may be spaced at least 1mm (0.040 inch) apart. A circular chart shall make one revolution in not more than 12 hours.

(C) Starter Vats with temperatures above 80°C

Recording thermometers shall use charts graduated in temperature scale divisions of 1°C (2°F), spaced not less than 1mm (0.040 inch) apart between 73°C and 85°C, including treatment temperature, plus or minus 3°C (5°F), graduated in time scale division of not more than 15 minutes. A circular chart shall make one revolution in not more than 24 hours.

Recording Thermometer (Batch)
Table description

This table shows the inspection criteria by task for Recording Thermometer (Batch): 1.12.05.01 General Conditions (HS=3); 1.12.05.02 Recording Pen (HS=3); 1.12.05.03Sensor Location (HS=2); 1.12.05.04 Chart Specifications (HS=3) and 1.12.05.05 Accuracy (HS=2).

Task Inspection Criteria
1.12.05.01 General Conditions (HS=3) A. Requirements
  • Clean and in good condition
  • Proper design
    • protected against damage at 105°C
    • moisture-proof
    • spring or electrically operated
    • positive drive mechanism equipped with a system to prevent slippage of chart
  • Records and frequency of servicing (at least once a year)
1.12.05.02 Recording Pen (HS=3) A. Requirements
  • Functioning/Operating
    • ink present
  • Thickness of pen not greater than 0.7 mm (0.025")
  • Pen follows reference arc
1.12.05.03 Sensor Location (HS=2) A. Requirements
  • Recording and indicating thermometer sensors/bulbs sit as close as possible to each other
  • Sensors submerged in product during processing
1.12.05.04 Chart Specifications (HS=3) A. Requirements
  • Same unit of measure as the indicating thermometer
    • For processing temperature above 72°C
  • Charts calibrated in 1°C (2°F) divisions, spaced not less than 1mm (0.040") apart between 65°C and 77°C, including pasteurization temperature, plus or minus 3°C (5°F)
  • Charts graduated in 15 minute intervals
  • Circular chart to rotate one revolution in not more than 24 hours
    1. For processing temperature below 72°C
  • Charts calibrated in 0.5°C (1°F) divisions, spaced not less than 1.6mm (0.0625") apart between 60°C and 69°C, including pasteurization temperature, plus or minus 3°C (5°F), unless ink line is thin enough to distinguish from chart line then spacing can be 1mm (0.040 inch) apart.
  • Charts graduated in 10 minute intervals
  • Circular chart to rotate one revolution in not more than 12 hours
    2. For processing temperature above 80°C (starter vats)
  • Charts calibrated in 1°C (2°F) divisions, spaced not less than 1mm (0.040") apart between 73°C and 85°C, including treatment temperature, plus or minus 3°C (5°F)
  • Charts graduated in 15 minute intervals
  • Circular chart to rotate one revolution in not more than 24 hours
1.12.05.05 Accuracy (HS=2) A. Records
  1. General
    • Available; easily accessible
    • Tests performed at least annually or as required
    • Satisfactory follow up on out of specification findings
  2. Required Tests and Accuracy performed according to required methods and standards
    • Temperature accuracy
      • accurate to within +/- 0.5°C (1°F) for processing temperature between 60 and 71°C and within +/- 1°C (2°F) for processing temperature above 71°C
    • Time accuracy
      • recorded time does not exceed true elapsed time
    • Recording thermometer check against indicating thermometer
      • recording thermometer does not read higher than indicating thermometer
      • actual indicating thermometer reading and time of the verification marked daily onto the chart by the operator

1.12.05.05 Accuracy

The performance accuracy of the batch pasteurizer recording thermometer shall be verified at least once a year. Records of tests performed to determine accuracy shall be maintained in the plant's files. Tests which should be performed include the following:

  1. Recorder Temperature Accuracy: The temperature recorded shall be accurate to within +/- 0.5°C (1°F) for processing temperature between 60°C and 71°C and within +/- 1°C (2°F) for processing temperature above 71°C
  2. Recorder Time Accuracy: The recorded time of pasteurization shall not exceed the true elapsed time.
  3. Recording Thermometer Check Against Indicating Thermometer: The recording thermometer shall not read higher than the corresponding indicating thermometer. The actual indicating thermometer reading shall be marked daily onto the chart, by the operator, with the time of verification marked as well.

Testing methods shall comply with the required standards, and must show satisfactory follow-up on out of specification findings. Plant management must investigate the safety of the product produced with out of calibration equipment.

Date modified: