High Pressure Processing (HPP) FAQs
High Pressure Processing (HPP) — also known as cold pasteurization — is a non-thermal food safety method that uses ultra-high water pressure to deactivate harmful microbes and extend refrigerated shelf life without heat or preservatives.
Start here with answers to our most common HPP questions — or reach out if you don't see yours listed.
High Pressure Processing, also known as cold pasteurization, is a non-thermal food preservation method that uses extremely high levels of hydrostatic (water-based) pressure to deactivate harmful bacteria, molds, yeasts, and other microorganisms in food and beverages.
Unlike traditional pasteurization methods that rely on heat, HPP preserves the integrity of the product while improving food safety and extending refrigerated shelf life. It is widely used in clean-label food preservation.
Prepackaged food or beverages are placed in a specialized chamber filled with cold water. The chamber applies pressure up to 87,000 psi — equivalent to six times the pressure found at the deepest parts of the ocean. That pressure disrupts the cellular structure of pathogens and spoilage organisms, deactivating them while maintaining the product's taste, texture, color, and nutritional value.
Because the pressure is hydrostatic, it reaches every part of the package at once, regardless of the product's size or shape. Nothing is added to the product and no heat is applied.
Extended refrigerated shelf life. HPP extends product shelf life from as little as a few days up to several months. Every product is unique and must undergo testing to determine an exact shelf life, but most products see a shelf life increase of at least 5 times what they would have without HPP.
Enhanced food safety. HPP effectively destroys harmful pathogens found in food that make people sick, including E. coli, Salmonella, and Listeria. Deactivating these microorganisms also keeps products from spoiling prematurely.
Improved product quality. HPP helps maintain the sensory attributes of food — taste, texture, color, and nutritional value — far better than high heat pasteurization or the use of chemical preservatives.
Clean ingredient label. Using HPP typically eliminates the need for chemical preservatives. Each product varies and must take into consideration properties such as pH, but HPP is effective at destroying the spoilage organisms that make foods and beverages go bad quickly, often removing the need for added preservatives.
Reduction in food waste. Because HPP preserves fresh foods and beverages that would otherwise have a very limited shelf life, it keeps large volumes of product out of landfills.
Lower environmental impact. Applying HPP requires significantly less energy than heat pasteurization. It also uses less water, and the water can often be reused again and again.
Compared with thermal pasteurization specifically, HPP avoids the nutrient loss, flavor degradation, and color changes that sustained heat causes, which is why it is often chosen for products where freshness is part of the market position.
No. HPP is a non-thermal food preservation method and does not rely on elevated temperatures.
It does generate adiabatic heat — a temporary, localized temperature increase during pressurization. That heat does not cook the product or alter taste, texture, or color. The rise is small, typically a few degrees, and it dissipates quickly once pressure is released.
This differs from thermal processing, which involves sustained exposure to high external temperatures and can alter flavor, texture, and nutritional value. Because HPP avoids that sustained heat, it preserves vitamins, minerals, and enzymes along with fresh taste and natural texture.
HPP is widely used to improve the safety and refrigerated shelf life of:
Meat and Poultry
Seafood
Dairy Products
Beverages
Fruits and Vegetables
Foods for Kids
Dips, Sauces, and Spreads
Ready-to-Eat Meals
Plant-Based and Alternative Proteins
Pet Food
HPP is not a viable process for dry, porous, or oily products such as bread, whole fresh produce, or peanut butter — though nut butters can be used as ingredients in HPP'd products.
Liquids, proteins, fruit and vegetable blends, and other high-moisture refrigerated foods are common HPP candidates. Product suitability also depends on water activity, pH, formulation, physical structure, and packaging.
Yes. Certain foods and beverages are not well-suited for HPP because of their moisture content, pH level, fat composition, or physical structure.
Dry products such as powders lack the available moisture HPP needs to deactivate microorganisms.
Low-acid products (pH ≥ 4.6) are at risk for the growth of Clostridium botulinum spores, which can produce harmful toxins. Low-acid products that cannot be made more acidic are better suited to heat-based pasteurization or preservatives.
High-oil products such as peanut butter may appear liquid, but their oil content limits available water, making HPP ineffective for extending shelf life or destroying pathogens.
Bakery products such as bread, cookies, and cakes contain air pockets that compress under pressure, crushing or compacting the product.
Delicate fresh produce such as leafy greens is susceptible to physical damage during HPP, resulting in wilting and loss of quality.
For products that don't meet HPP requirements, alternative preservation methods such as thermal pasteurization or formulation adjustments to increase acidity may be more effective. Testing and formulation adjustment are both worth doing before committing to a process.
Both involve moisture, but they measure different things, and only one of them predicts how a product will behave under pressure.
Water content is the total amount of water in a product, expressed as a percentage of its weight. A product can have high water content and still be a poor HPP candidate if that water isn't available for microbial activity.
Water activity (Aw) measures the free, unbound water available for microbial growth, on a scale from 0 (completely dry) to 1 (pure water). It is not the same thing as percent moisture.
HPP generally performs best in foods with high water activity. Low water activity reduces microbial deactivation, which is why products like dry powders, crackers, and peanut butter are poor candidates even when they contain measurable moisture. Fresh juices, salsas, and deli meats have the available water HPP needs. Ohio State University Extension covers this in its fact sheet on high-pressure-based technologies in the food industry.
No. Products must be fully thawed and held at refrigerated temperatures before processing. Ice crystals prevent pressure from transmitting evenly through the product, which can leave untreated areas and compromise microbial reduction.
Products can be frozen immediately after HPP to preserve freshness and extend shelf life. This is common for proteins, raw pet foods, and other high-moisture products.
No. HPP is a pasteurization process, not a sterilization process. It does not eliminate all microorganisms — some spores are highly resistant to even extreme pressure. Sterilization requires complete elimination of all microorganisms, including spores, which generally demands high heat, chemical stabilizers, or preservatives.
What HPP does do is effectively reduce illness-causing and spoilage microorganisms, including E. coli, Listeria, and Salmonella. HPP typically achieves a 5-log reduction — a 99.999% reduction in microbial load, a level sufficient to make food safe for consumption under most regulatory and industry standards.
As a cold pasteurization method, HPP prioritizes preservation of sensory and nutritional quality while significantly improving food safety and shelf life. It also often eliminates the need for chemical preservatives in products designed for refrigerated distribution.
Yes. HPP does not destroy bacterial spores, including those of Clostridium botulinum. Under the right conditions those spores can become active bacteria and produce neurotoxins harmful to the central nervous system.
C. botulinum spores are most prevalent on the surfaces of fruits and vegetables, which puts products like salsa, baby food, and cold-pressed juices particularly at risk if they are not properly formulated, processed, and handled.
The vast majority of HPP-treated products must maintain a pH below 4.6, since C. botulinum cannot grow in high-acid environments. Products at or above that range are comparatively uncommon HPP applications and may be better suited to thermal pasteurization depending on formulation and shelf-life requirements.
To reduce the risk, work with a laboratory experienced in HPP to adjust formulation, and increase acidity through natural or approved additives such as citrus juices or citric acid. APC's food safety team can help develop safe, natural formulations that prevent spore growth, and can connect you with an appropriate HPP-experienced laboratory.
For more information on C. botulinum prevention, see FDA's Fish and Fishery Products Hazards and Controls Guidance.
These studies establish whether HPP achieves the microbial reduction your product needs to meet food safety standards.
A validation study verifies that your HPP parameters — pressure level, hold time, temperature — effectively deactivate harmful microorganisms in your specific product. The product is tested under HPP conditions and the results are analyzed against regulatory and industry safety standards.
An inoculation study confirms HPP's effectiveness against specific target pathogens such as E. coli, Listeria monocytogenes, or Salmonella. The product is intentionally inoculated with a known quantity of the target organism, then processed, and the reduction is measured under controlled conditions. Results are evaluated for compliance with FDA, USDA, and industry safety requirements.
Your product may need one of these studies if it is a high-risk product such as a ready-to-eat food, fresh juice, or low-acid item; if it is new to market; or if regulatory agencies or industry standards require proof of microbial safety.
Beyond compliance, these studies determine the most effective HPP parameters for your product — which in turn determines the refrigerated shelf life you can assign to it.
APC's food safety team works with accredited laboratories to guide you through validation and inoculation studies, helping you understand study requirements, coordinate testing, and interpret results. Our Food Quality and Safety page explains that process in more detail.
No. HPP does not make products shelf-stable. Products must be kept at or below 40°F at all times, with the cold chain never broken.
Shelf life depends on the product's initial microbial load, the types of microorganisms present, HPP hold time, and storage conditions. All HPP-treated products must be refrigerated, and many can also be frozen to extend shelf life further.
Fresh, never-heated products — cold-pressed juices, raw plant and animal proteins, and dips like salsa and guacamole — typically see shelf life extended from a few days to several weeks or months. Cooked products such as deli meats, ready-to-eat proteins, side dishes, and prepared meals can last several additional months without added preservatives.
To hold that shelf life, products must be stored at or below 40°F, handled in accordance with food safety regulations, and kept frozen for extended storage when appropriate. HPP dramatically reduces harmful pathogens, but cold chain conditions still govern whether the product performs as validated.
Because HPP avoids heat, it retains significantly more of the naturally occurring vitamins, minerals, and enzymes than thermal pasteurization — including vitamin C, B vitamins such as B1, B2, B6, and B12, polyphenols and other plant-based antioxidants, and enzymes important for digestion and bioactivity.
That makes HPP a strong choice for brands whose products carry nutrient-density or clean-label claims.
In most cases, no. HPP preserves natural taste and texture exceptionally well. Because it uses cold water pressure instead of heat, it avoids the flavor degradation, "cooked" notes, and structural breakdown associated with thermal pasteurization.
Some products do experience minor sensory changes depending on composition, structure, or packaging. Emulsions such as salad dressings and creamy dips may require formulation adjustments, and aerated foods can lose structure under pressure.
APC recommends starting with an organoleptic test to assess flavor, texture, color, and aroma. Our team can help interpret the results and guide formulation or packaging adjustments where they are needed. Our Innovation Center is set up for exactly this kind of pre-production evaluation.
HPP helps food retain its fresh, vibrant appearance because it avoids the heat that typically causes discoloration and pigment breakdown. It also slows oxidative degradation, which delays discoloration until after the product is opened and exposed to air.
Cold-pressed juices retain vibrant orange, red, and green tones longer than heat-treated versions. Guacamole stays green without added preservatives. Deli meats, dips, and wet salads keep their original color.
For brands focused on clean labels, premium positioning, or refrigerated retail, that visual integrity supports shelf appeal and customer trust while reducing the need for artificial color stabilizers.
In most cases, yes. HPP significantly reduces — and often removes — the need for chemical preservatives, which lets manufacturers offer simpler ingredient lists and extend shelf life without synthetic additives.
Formulation still plays a role, and pH is the most important factor. Lower pH enhances microbial deactivation, making HPP even more effective. Acidic products such as fresh juices, salsas, and dips often require no additional preservatives after HPP. Products with higher pH levels, borderline microbial stability, unusually long shelf-life targets, or inconsistent handling conditions may still need them.
Microbial testing and shelf life studies establish which category a product falls into. A validation or inoculation study can verify results without preservatives.
There is no federal requirement in the U.S. to disclose that a product has undergone HPP, and most products on the market do not carry an explicit HPP label. Many manufacturers choose to promote it anyway, particularly in premium, clean-label, or health-conscious categories, because HPP allows them to eliminate or reduce synthetic preservatives and shoppers associate shorter ingredient lists with fresher processing.
Companies that are members of the Cold Pressure Council (CPC) may use the Verified Cold Pressure logo if they are members in good standing and have completed third-party validation of their HPP process. The logo communicates that the product has been treated with HPP for food safety and freshness and meets industry best practices for process verification.
HPP requires packaging that can withstand extreme hydrostatic pressure without rupturing or leaking. Several plastic packaging formats are designed for HPP environments.
Made from high-density polyethylene (HDPE), polypropylene (PP), or laminated films. They withstand high pressure and prevent oxygen or gas exchange, and the flexible format allows more product to fit into the HPP vessel per cycle, which reduces processing cost. Common applications include deli meats, sauces, dips, and baby food squeeze pouches.
Constructed from PET, HDPE, or PP. Suitable for ready-to-eat meals, wet salads, cold-soaked oats, soups, and salsas.
Used to seal rigid containers. The seal must be secure and pressure-resistant to prevent water from entering the package; improper sealing compromises both safety and product integrity.
Among the compatible materials, HDPE is durable, food-safe, and highly pressure-resistant. PP is strong and flexible across a range of formats. PET is lightweight and robust, common for beverages and food trays. Polycarbonate is rigid and clear, often used for cold-pressed juice bottles.
Packaging should be tested in pilot runs to confirm compatibility with HPP conditions before commercial production.
HPP uses ultra-high hydrostatic pressure — up to 87,000 psi (600 MPa) — to deactivate harmful microorganisms and extend shelf life without heat. The process uses cold water, maintaining the product's temperature and preserving its sensory and nutritional quality.
The equipment that delivers it includes specialized pressure vessels designed to safely contain sealed products during pressurization, cold water systems that surround the products and transmit pressure evenly, automated loading and unloading systems, precision controls for pressure hold times and safety validation, reinforced construction to withstand repeated extreme pressure cycles, and water recycling systems.
Products must be packaged in flexible, water-resistant materials — typically high-barrier plastic films and containers — and the package must remain sealed and intact throughout pressurization.
Yes. Products treated with HPP must comply with regulatory standards set by the FDA and USDA. Each product undergoes an evaluation process to identify and address potential food safety risks.
Regulatory agencies review scientific data to understand the risks and benefits of ingredients, production methods, and pasteurization processes, identifying potential hazards, allergens, and contaminants. Risk assessment evaluates health effects, determines safe consumption levels, and identifies vulnerable populations such as infants, pregnant women, and people with health conditions. Agencies then establish rules based on those findings, take public input from industry representatives, consumer groups, and health professionals, and enforce compliance through inspections, product sampling, label and claim reviews, and — where necessary — warnings, recalls, or legal action.
Working with an experienced food and beverage laboratory and following the recommendations of APC's food safety team helps minimize regulatory risk. For further detail, see FDA guidance for food manufacturers.
A Hazard Analysis and Critical Control Points (HACCP) plan is a systematic approach to food safety that identifies, evaluates, and controls hazards throughout production.
The vast majority of products require a HACCP plan — either because applicable FDA or USDA requirements call for one, or because APC requires one as part of its own food-safety and processing system. APC requires a HACCP plan for every product entering its manufacturing and processing facilities. APC itself operates under HACCP-based food-safety controls, so this applies to products processed through APC even in the relatively limited circumstances where a product category is not independently subject to a specific federal HACCP mandate.
A HACCP plan has seven elements:
HPP is typically more expensive on a per-unit basis than heat pasteurization or chemical additives. Total cost depends on product type and complexity, packaging materials and compatibility, volume processed per run, and the level of microbiological testing or validation required.
Those upfront costs are frequently offset by reduced spoilage, significantly reduced recall risk, extended refrigerated shelf life, improved inventory management and lower shrink, access to more retail channels and premium pricing, and stronger clean-label positioning.
APC offers HPP as a per-pound service, which makes it accessible to emerging brands, startups, and boutique producers without capital investment in equipment. Larger companies use the same model to avoid the operational complexity, staffing, and maintenance that owning HPP systems requires — an investment that typically runs into the millions.
When customers manufacture, HPP, and assemble products under one roof at APC, incremental HPP costs are often offset again by lower freight and cold chain logistics costs, reduced refrigeration and storage expense, and faster time to market.
Compared with thermal pasteurization, HPP avoids continuous heating and cooling cycles, which lowers energy demand. The same cold water is recycled across multiple HPP cycles. Extended shelf life reduces the need for refrigerated transport and storage. And because HPP removes the need for synthetic preservatives in many products, it reduces reliance on additives that carry their own environmental costs.
Compared with untreated fresh products, the difference is waste. Deli salads, store-made meals, and similar items spoil quickly and generate large volumes of waste. HPP extends their shelf life without compromising quality.
By extending shelf life without thermal damage, HPP helps prevent millions of pounds of food waste annually — conserving the water, land, and energy used to produce that food, the labor and logistics tied to short shelf life, and the greenhouse gas emissions generated when food decomposes in landfills. Our Environmental Impact page covers this in more depth.
HPP deactivates microorganisms through pressure rather than heat, and that requires protocols designed for pressure processing rather than adapted from thermal standards. A laboratory familiar only with heat processing may not design the right study or interpret the results correctly.
Laboratories experienced with HPP are better equipped to conduct appropriate shelf-life, validation and challenge, microbiological, and packaging testing — including for pressure-resistant organisms that can survive the process, and for how packaging materials behave under pressure.
Using an experienced laboratory reduces the risk of inaccurate studies, failed validation, and compliance problems. APC works with accredited laboratories that have direct HPP experience and can connect you with one suited to your product and the study you need.
For more than 20 years, American Pasteurization Company (APC) has been a leader in HPP innovation, delivering clean-label food preservation solutions to food and beverage brands across the U.S. and Canada.
Our expertise in high pressure processing empowers manufacturers to deliver products that are fresher, safer, and longer-lasting — all without compromising quality. And with our deep experience in premium product manufacturing, we help bring your most innovative food ideas to life.
Tell us about your product and what you're trying to accomplish with HPP.
