Flash pasteurization is a short, hot treatment of a liquid. FDA's juice HACCP regulator training uses that name for a continuous process that holds juice for seconds, and high-temperature short-time (HTST) for the broader continuous method. For milk, the Pasteurized Milk Ordinance states an HTST time and temperature. Those milk figures are not a juice process.

What flash pasteurization is

FDA's Juice HACCP Regulator Training describes two thermal pasteurization methods used in juice processing.

The batch method applies heat to one lot of juice, holds that lot, and then cools it. The continuous method pumps juice from a storage vessel through heat exchanger plates, then through holding tubes, and then back through heat exchangers. The page states: "Temperatures used in the continuous method are usually higher than those used in a batch system. This results in faster destruction of the pathogen and a much shorter holding time is required. For this reason, such systems are called 'high temperature short time' or HTST pasteurization. Some processors will use very high temperatures in order to further reduce holding times to seconds instead of minutes. Such systems are referred to as 'flash pasteurization' or ultra-high temperature, UHT systems."

On that page, flash pasteurization is the seconds-long hold. HTST is the name it uses for the continuous method as a class. The page does not state one temperature for either name in juice. It states that pasteurization has historically been used for fluid milk, that appropriate heating requirements for dairy products are well established, and that appropriate parameters for juice products are not as well established. It states that any pasteurization process should be validated for each specific product. It also states: "Pasteurization will not kill all microorganisms present and will not provide a shelf-stable product."

The Grade "A" Pasteurized Milk Ordinance, 2025 Revision, does not use the word flash. The abbreviation list expands HTST as High-Temperature-Short-Time and HHST as Higher-Heat-Shorter-Time. Definition SS states that the terms "pasteurization," "pasteurized," and similar terms shall mean the process of heating every particle of milk or milk product, in properly designed and operated equipment, to one of the temperatures in the following chart and held continuously at or above that temperature for at least the corresponding specified time.

Batch (vat) pasteurization, milk or milk product

TemperatureTime
63°C (145°F)*30 minutes

Continuous flow (HTST and HHST) pasteurization, milk or milk product

TemperatureTime
72°C (161°F)*15 seconds
89°C (191°F)1.0 second
90°C (194°F)0.5 seconds
94°C (201°F)0.1 seconds
96°C (204°F)0.05 seconds
100°C (212°F)0.01 seconds

The ordinance's footnote to the rows marked with an asterisk states: "If the fat content of the milk product is ten percent (10%) or greater, or a total-solids of 18% or greater, or if it contains added sweeteners, the specified temperature shall be increased by 3°C (5°F)." The same definition gives eggnog its own chart: batch (vat) pasteurization at 69°C (155°F) for 30 minutes, and continuous flow (HTST) pasteurization at 80°C (175°F) for 25 seconds or 83°C (180°F) for 15 seconds. The chart heading groups HTST and HHST. It does not label each row as one or the other. These times and temperatures are for milk or milk product, and the eggnog lines are for eggnog. They are not a process for juice or for every beverage.

21 CFR 131.3(b) is a separate definition. "Pasteurized," when used to describe a dairy product, means that every particle of such product shall have been heated in properly operated equipment to one of the temperatures in its table and held continuously at or above that temperature for the specified time, or another time and temperature relationship which has been demonstrated to be equivalent in microbial destruction.

TemperatureTime
145°F30 minutes
161°F15 seconds
191°F1 second
204°F0.05 second
212°F0.01 second

The footnote in § 131.3 states: "If the dairy ingredient has a fat content of 10 percent or more, or if it contains added sweeteners, the specified temperature shall be increased by 5°F." That footnote does not mention total solids. The table also does not list the 194°F or 201°F rows that appear on the ordinance chart. Use the table that belongs to the document you are reading. Both are about a dairy product or milk, not about juice.

Section 131.3(c) states: "Ultra-pasteurized when used to describe a dairy product means that such product shall have been thermally processed at or above 280°F for at least 2 seconds, either before or after packaging, so as to produce a product which has an extended shelf life under refrigerated conditions." The ordinance's definition of ultra-pasteurization uses the same idea for a milk and/or milk product: thermally processed at or above 138°C (280°F) for at least two seconds, either before or after packaging, so as to produce a product which has an extended shelf-life under refrigerated conditions, and it refers to 21 CFR 131.3. That is the defined term ultra-pasteurized. It is not the sentence on FDA's juice training page that groups flash pasteurization with UHT, and that sentence does not state 280°F.

University of Minnesota Extension, on a page about pasteurized milk for calves, says to use Pasteurized Milk Ordinance times and temperatures, and it lists "High Temperature – Short Time (or flash) pasteurizer: 161 degrees F for 15 seconds" and "Batch pasteurization: 145 degrees F for 30 minutes." That page is where a primary source pairs the word flash with the 15-second milk step. The product in that sentence is milk.

What flash pasteurized means on a label

21 CFR 101.17(g) and 21 CFR Part 120 do not define "flash pasteurized." A line of label copy that uses those words is not, by itself, a citation of the milk chart or of a juice critical limit.

FDA's Small Entity Compliance Guide on juice HACCP answers the question of labeling a product as pasteurized this way: "Pasteurization is a heat treatment sufficient to destroy pathogens. Therefore, to be labeled as 'pasteurized,' a juice must be heat treated to destroy pathogens." The same answer set states that use of the term "pasteurized" on products treated with UV light to attain the 5-log reduction is misleading, and that the product would be considered misbranded under section 403(a) of the Federal Food, Drug, and Cosmetic Act. The guide's examples of wording for a UV-treated juice are "treated with UV light to control pathogens," "treated with UV light to control harmful bacteria," or "UV treated."

Section 101.17(g) is titled, for this paragraph, "Juices that have not been specifically processed to prevent, reduce, or eliminate the presence of pathogens." For that paragraph, juice means the aqueous liquid expressed or extracted from one or more fruits or vegetables, purees of the edible portions of one or more fruits or vegetables, or any concentrate of such liquid or puree. The label of any juice that has not been processed in the manner described in paragraph (g)(7), or of any beverage containing juice where neither the juice ingredient nor the beverage has been so processed, shall bear this warning statement:

"WARNING: This product has not been pasteurized and, therefore, may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems."

The word "WARNING" shall be capitalized and shall appear in bold type. The statement shall appear prominently and conspicuously on the information panel or on the principal display panel, and, when on a label, shall be set off in a box by use of hairlines.

Paragraph (g)(7) says the warning requirements shall not apply to a juice that has been processed in a manner that will produce, at a minimum, a reduction in the pertinent microorganism for a period at least as long as the shelf life of the product when stored under normal and moderate abuse conditions, of either a 5-log (that is, 100,000-fold) reduction, or a reduction equal to or greater than the criterion established for process controls by any final regulation requiring HACCP principles for juice. The pertinent microorganism, for that paragraph, is the most resistant microorganism of public health significance that is likely to occur in the juice.

The warning does not apply to juice that is not for distribution to retail consumers in the form shipped and that is for use solely in the manufacture of other foods, or that is to be processed, labeled, or repacked at a site other than where it was originally processed, provided that, for juice not processed as paragraph (g)(7) describes, the lack of such processing is disclosed in documents accompanying the juice, in accordance with the practice of the trade.

The compliance guide states that, generally speaking, use of the juice label warning statement is not an alternative to compliance with the HACCP regulations. It states that juice required to be produced under a HACCP system that is not so produced will be considered adulterated.

Illustrative only: a refrigerated juice bottle might show the words flash pasteurized under the brand name. Those words do not state a holding time, a temperature, the pertinent microorganism, or whether the heat step was validated for that juice. The plant's HACCP plan is the record. The sentence is an illustration of a label, not a finding about a product on the market.

How the heat steps differ

Batch and continuous, for juice. FDA's training page separates the batch method from the continuous method, as quoted above. Holding time in the continuous method is set by the pump rate and by holding tubes designed to keep the juice at the temperature for the time needed to achieve the 5-log standard. The page states that HTST systems frequently contain flow diversion valves, which redirect juice that does not meet the minimum temperature requirement back to the storage tank for reprocessing. If the equipment does not have that feature and the juice misses the minimum temperature in the HACCP plan, the firm must document that the juice was separated to be reprocessed, under the corrective actions in 21 CFR 120.10.

Vat, HTST, and the shorter continuous holds, for milk. The ordinance chart above is the comparison, and only for milk or milk product. Batch (vat) is 63°C (145°F) for 30 minutes. The first continuous-flow row is 72°C (161°F) for 15 seconds. The same chart continues through 100°C (212°F) for 0.01 seconds. The fat, solids, and sweetener footnote applies to the starred rows. Eggnog uses the separate lines in that definition. Section 131.3 is the dairy-product definition of the word pasteurized, with its own table and its own footnote.

Ultra-pasteurized, for a dairy product. Section 131.3(c) and the ordinance definition quoted above use at or above 280°F, or 138°C (280°F), for at least 2 seconds. That defined term is not a license to print the same figures on a juice label.

Juice is not the milk chart. The training page says juice parameters are not as well established as dairy heating requirements, and that the process has to be validated for each specific product. FDA's juice hazards and controls guidance (March 2004) summarizes studies and then states FDA's comments. It says a study done by the NFPA resulted in a recommended general thermal process of 3 seconds at 71.1°C (160°F) for a 5-log reduction for E. coli O157:H7, Salmonella, and Listeria monocytogenes in fruit juices, measured using single-strength apple, orange, and white grape juices adjusted to a pH of 3.9. FDA's comment on that page: the agency believes that process is adequate for those three vegetative bacterial pathogens at juice pH values comparable to those in the study, and that other validation studies may be needed for juices with pH values greater than 4.0.

The same guidance says neither that study nor a University of Wisconsin apple-cider study evaluated Cryptosporidium parvum. For apple juice at pH values of 4.0 or less, the guidance recommends these thermal processes for a 5-log reduction for oocysts of Cryptosporidium parvum, in addition to those three vegetative bacterial pathogens: 160°F for 6 seconds, 165°F for 2.8 seconds, 170°F for 1.3 seconds, 175°F for 0.6 seconds, or 180°F for 0.3 seconds. It also states that the agency believes the process typically carried out for milk pasteurization, 71.7°C (161°F) for 15 seconds, is adequate to achieve a 5-log reduction of Cryptosporidium parvum oocysts and those three vegetative bacterial pathogens when that process is used for apple juice at pH values of 4.0 or less. That sentence is about apple juice at that pH. It is not a process for every beverage. The ordinance's 72°C (161°F) and this guidance's 71.7°C (161°F) are each quoted from its own document.

The compliance guide states: "Precise times and temperatures depend on the type of juice you make and your process." It also states that, except for processors of thermally processed shelf-stable juices and juice concentrates, a juice processor cannot assume a heat treatment meets the 5-log pathogen reduction requirement. The processor must establish and meet critical limits so the heat process fulfills that standard.

Retort. A retorted low-acid food is a different rule. 21 CFR 120.24(a)(1) exempts a juice processor subject to part 113 or part 114 from the 5-log paragraph, and what retort processing is is the note on the part 113 thermal process for a hermetically sealed container.

What juice HACCP requires

21 CFR 120.1(a) states that any juice sold as such or used as an ingredient in beverages shall be processed under Part 120. Juice means the aqueous liquid expressed or extracted from one or more fruits or vegetables, purees of the edible portions of one or more fruits or vegetables, or any concentrates of such liquid or puree. Raw agricultural ingredients of juice are not subject to the part.

Section 120.3(k) defines a processor as any person engaged in commercial, custom, or institutional processing of juice products, either in the United States or in a foreign country, including any person engaged in the processing of juice products intended for use in market or consumer tests. Section 120.3(n) defines a shelf-stable product as a product that is hermetically sealed and, when stored at room temperature, should not demonstrate any microbial growth.

Section 120.24(a) states that, to meet subpart A, processors of juice products shall include in their HACCP plans control measures that will consistently produce, at a minimum, a 5 log reduction, for a period at least as long as the shelf life of the product when stored under normal and moderate abuse conditions, in the pertinent microorganism. The pertinent microorganism is the most resistant microorganism of public health significance that is likely to occur in the juice. Section 101.17(g)(7)(i)(A) states the same magnitude as a 5-log (that is, 100,000-fold) reduction. The compliance guide describes the performance standard as at least a 100,000-fold decrease in the number of microorganisms, and it states that a 5-log reduction in a bacterial plate count does not meet the requirement. The reduction has to be targeted to the pertinent pathogen. The guide says the pertinent pathogen may vary with the juice and the treatment, though typically it would be Salmonella, Escherichia coli O157:H7, or Cryptosporidium parvum.

Two processors are exempt from § 120.24(a). One is a juice processor subject to the requirements of part 113 or part 114. The other is a juice processor using a single thermal processing step sufficient to achieve shelf-stability of the juice, or a thermal concentration process that includes thermal treatment of all ingredients, provided the processor includes a copy of the thermal process in the written hazard analysis required by § 120.7. The compliance guide states that this exemption does not remove the duty to include that copy of the thermal process.

Section 120.24(b) states that processors shall meet paragraph (a) through treatments applied directly to the juice, except that citrus juice processors may use treatments to fruit surfaces, provided the 5-log reduction process begins after culling and cleaning as defined in § 120.3(a) and (f) and the reduction is accomplished within a single production facility. Section 120.24(c) states that processors shall meet paragraphs (a) and (b) and perform final product packaging within a single production facility operating under current good manufacturing practices. A processor claiming an exemption under (a)(1) or (a)(2) shall also process and perform final packaging of all juice subject to the claimed exemption in one such facility.

The compliance guide states that a 5-log reduction can be one control measure or a combination that has a cumulative effect. It names heat and, as an example of a non-heat control, high pressure. Citrus processors may use surface treatments. All other juice processors must apply the 5-log process to the juice. The guide states that the entire 5-log reduction must be accomplished within a single production facility.

Section 120.8(a) states that a HACCP plan shall be specific to each location where that processor processes juice, and to each type of juice processed. Types may be grouped when the hazards, critical control points, critical limits, and required procedures are essentially identical, if anything unique to a specific product or method is delineated in the plan and observed in practice. Section 120.11(b) states that each processor shall validate that the HACCP plan is adequate to control food hazards that are reasonably likely to occur. That validation shall occur at least once within 12 months after implementation and at least annually thereafter, or whenever any changes in the process occur that could affect the hazard analysis or alter the HACCP plan.

For continuous HTST equipment, the juice hazards guidance recommends designating the juice temperature and the juice heating time as critical limits, continuously monitoring juice temperature, and, when a positive-displacement timing pump and the holding tube are built to deliver a controlled flow, checking the pump set point rather than continuously monitoring heating time. Those sentences are recommendations in the guidance. The critical limits for a SKU are the ones in that SKU's HACCP plan.

Current good manufacturing practice for the plant is a separate question, covered in what cGMP is. This note is not a product-specific determination.

Questions to ask a co-packer

NXTCPG's published work is co-manufacturer selection, ingredient sourcing, and quality and scale readiness, in Source & produce. It does not state a pasteurizer. Who manufactures, who packs, who owns the formula, and what a pilot must show are in how to choose a co-packer.

  • Is this SKU juice under § 120.1, sold as juice or used as an ingredient in a beverage? If it is a dairy product, which document supplies the time and temperature: § 131.3, the Pasteurized Milk Ordinance, or both?
  • Who is the processor under § 120.3(k) for this juice? Is the HACCP plan specific to this location and this type of juice, as § 120.8 requires?
  • Is the step a batch method or a continuous method? Which name does the plant use: HTST, flash pasteurization, UHT, or ultra-pasteurized? Which written definition is that name taken from?
  • What are the critical limits for this juice: temperature, holding time, and flow? For a continuous system, how is holding time fixed, and what happens to juice that misses the minimum temperature?
  • What is the pertinent microorganism for this juice? Where is the validation that the plan produces at least a 5-log reduction for a period at least as long as the shelf life when the product is stored under normal and moderate abuse conditions?
  • Is the 5-log treatment applied to the juice? If the juice is citrus and the plant uses a surface treatment, does the reduction begin after culling and cleaning, and is it finished in one facility? Is final packaging in that same facility, under § 120.24(c)?
  • Is the plant claiming the part 113, part 114, or shelf-stable exemption in § 120.24(a)? If so, where is the thermal process in the hazard analysis?
  • When was the HACCP plan last validated under § 120.11(b)?
  • If the label says pasteurized or flash pasteurized, what heat treatment do those words refer to? If the juice has not been processed as § 101.17(g)(7) describes, does the label carry the warning, in the form that paragraph requires?
  • Will any untreated juice or untreated flavor be added after the treatment? The compliance guide states that all ingredients of the juice must have received a 5-log reduction.

Get the answers for this SKU from this plant. A time or a temperature from milk, from apple juice at a stated pH, or from another formula is a figure for that other case.

Where this sits with NXTCPG

Choosing the plant sits in Source & produce. If the open question is which co-packer can run the beverage, and which pasteurization question the project needs answered, start a project. For equipment, minimums, who buys the ingredients, and who owns the formula, use how to choose a co-packer. For the manufacturing-practice rule under that choice, use what cGMP is.

Sources

FAQ

What is flash pasteurization?

FDA's Juice HACCP Regulator Training states that continuous pasteurization systems, which usually use a higher temperature and a shorter holding time than a batch system, are called "high temperature short time" or HTST pasteurization. The same page states that some processors use very high temperatures to reduce holding times to seconds instead of minutes, and that such systems are referred to as "flash pasteurization" or ultra-high temperature, UHT systems. The Grade "A" Pasteurized Milk Ordinance, 2025 Revision, does not use the word flash. Its abbreviation list expands HTST as High-Temperature-Short-Time and HHST as Higher-Heat-Shorter-Time. Definition SS defines pasteurization of milk or milk product and lists 72°C (161°F) for 15 seconds under the heading Continuous Flow (HTST and HHST) Pasteurization, with shorter holds in the same chart. That chart is for milk or milk product. University of Minnesota Extension, writing about milk for calves, calls a "High Temperature – Short Time (or flash) pasteurizer" the step of 161 degrees F for 15 seconds and says to use Pasteurized Milk Ordinance times and temperatures. That sentence is about milk.

What does flash pasteurized mean?

The juice sections cited in this note do not define the phrase flash pasteurized. FDA's Small Entity Compliance Guide on juice HACCP states that pasteurization is a heat treatment sufficient to destroy pathogens, and that to be labeled as "pasteurized," a juice must be heat treated to destroy pathogens. The same guide states that use of the term "pasteurized" on a juice treated with UV light is misleading. Under 21 CFR 101.17(g), the label of a juice that has not been processed as paragraph (g)(7) describes, or of a beverage containing juice where neither the juice ingredient nor the beverage has been so processed, shall bear this warning: "WARNING: This product has not been pasteurized and, therefore, may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems." Paragraph (g)(7) describes, among other things, a process that produces at least a 5-log (that is, 100,000-fold) reduction in the pertinent microorganism. The compliance guide states that the warning statement is not an alternative to the juice HACCP regulation. Words on a label are not the processing record.

What is flash pasteurized, if HTST is a different name?

It depends on which source is speaking. FDA's juice training page uses HTST for the continuous method and uses flash pasteurization for a very-high-temperature hold measured in seconds, grouped with UHT. The Pasteurized Milk Ordinance uses HTST and HHST on its continuous-flow chart for milk or milk product and does not use flash. University of Minnesota Extension uses "High Temperature – Short Time (or flash)" for 161 degrees F for 15 seconds in milk. 21 CFR 131.3 defines "pasteurized" and "ultra-pasteurized" for a dairy product and does not use flash, HTST, or UHT. Ask which document the plant is applying to this SKU before treating the words as the same step.

How does HTST pasteurization differ from vat pasteurization and from a retort?

For milk or milk product, the Pasteurized Milk Ordinance lists batch (vat) pasteurization at 63°C (145°F) for 30 minutes and lists 72°C (161°F) for 15 seconds on the continuous-flow (HTST and HHST) chart. A footnote in that definition raises the specified temperature by 3°C (5°F) when fat is 10 percent or greater, total solids are 18 percent or greater, or the product contains added sweeteners. FDA's juice training page describes a batch method, which heats one lot and holds it, and a continuous method, which pumps juice through a heat exchanger and a holding tube. Those juice paragraphs do not copy the milk chart. A retort is a different rule. Section 120.24(a)(1) exempts a juice processor subject to part 113 or part 114 from the 5-log paragraph, and the retort note covers the part 113 thermal process for a sealed container. FDA's training page states that pasteurization will not kill all microorganisms present and will not provide a shelf-stable product.

Is there one time and temperature for flash pasteurization of a beverage?

No single time and temperature in these sources applies to every beverage. For milk or milk product, use the Pasteurized Milk Ordinance chart, including the footnote, and do not copy it onto a juice. 21 CFR 131.3 states its own table for a dairy product, including 161°F for 15 seconds, and that table is not identical to the ordinance chart. For juice, FDA's Small Entity Compliance Guide states that precise times and temperatures depend on the type of juice and the process, and that a heat treatment cannot be assumed to meet the 5-log standard, except for the shelf-stable and concentrate case the guide describes. FDA's juice hazards guidance gives thermal-process recommendations for named juices at stated pH values, including apple juice at pH 4.0 or less. Those recommendations are for the juices and organisms named in that guidance.

What should a beverage brand ask a co-packer about flash pasteurization?

Ask whether the SKU is juice under 21 CFR 120.1, sold as juice or used as an ingredient in a beverage. Ask who the processor is under 21 CFR 120.3, and whether the HACCP plan is specific to this location and this type of juice under 21 CFR 120.8. Ask whether the step is a batch method or a continuous method, which name the plant uses for it, and what the critical limits are for this juice. Ask what the pertinent microorganism is and where the validation shows at least a 5-log reduction for the shelf life under normal and moderate abuse conditions, as 21 CFR 120.24(a) states. Ask whether the treatment is applied to the juice, or, for citrus, to the fruit surface, and whether final packaging is in the same facility. Ask whether a part 113, part 114, or shelf-stable exemption is claimed. Ask what "pasteurized" or "flash pasteurized" on the label refers to, and whether 21 CFR 101.17(g) requires the warning. This answer is not a product-specific determination.