D2C and FMCG brand owners
Launching a shelf-stable range, or moving an existing frozen or chilled SKU to ambient so it can be sold online and shipped without a cold chain.
Retort category
Soups and broths
Shelf-stable soups, broths, stocks and concentrates — from a clear bone broth to a cream soup that has to survive sterilization without curdling. We develop the formulation for the thermal process, validate it against the slowest-heating point in the pack, and produce the documentation your market asks for.
What we develop
Soups & Broths we take through the pilot
If it is a packaged product that needs to sit on an ambient shelf, it is a candidate for retort processing. Formulation and packaging are assessed for compatibility with thermal sterilization before any run, at our pilot retort unit in Chennai, India — and every product gets its own scheduled process rather than a borrowed one.
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Clear Broths and Stocks
Chicken, bone, vegetable and fish stocks where clarity and a clean mouthfeel are the whole product.
Develop a broth -
Cream and Velouté Soups
Dairy and plant-based cream soups, the hardest soups to hold together through a retort cycle.
Develop a cream soup -
Vegetable and Lentil Soups
Chunky and puréed vegetable, tomato, lentil and pulse soups for retail and foodservice.
Develop a vegetable soup -
Asian Noodle and Ramen Broths
Concentrated and ready-to-heat broths built to carry a noodle bowl.
Develop a noodle broth -
Concentrates and Bases
Reduced stocks and soup bases sold to kitchens and manufacturers by the litre.
Develop a concentrate -
Functional and Bone Broths
Collagen, protein and botanical broths sold on a nutritional claim as much as a flavour.
Develop a functional broth
Why a pilot first
Where soups and broths fail in a retort
These are the failures a pilot run is designed to surface — each of them cheap to find in twenty pouches and expensive to find in five thousand.
- Cream curdles Milk proteins coagulate under sterilization temperatures and the soup goes grainy, or separates outright.
- Solids settle out Particulates and insoluble fibre drop to the bottom of the pack, leaving a watery top and a sludge base.
- Body disappears Starch-thickened soups lose viscosity, turning a velvety soup into something closer to stock.
- Vegetables collapse Cut vegetables lose structure faster than the liquid around them, so a chunky soup arrives puréed.
- Cooked and sulphury notes Brassicas, alliums and proteins develop off-notes under sustained heat that were never in the kitchen version.
- Colour dulls Bright vegetable and tomato colours flatten, and dairy soups take on a cooked, yellowed cast.
None of these show up in a kitchen trial. They show up in a retort.
What we change
The levers we pull to make it survive the cycle
Reformulating for retort is not about weakening the product. It is about choosing ingredients and ratios that arrive at the right result after the heat, rather than before it.
- Protein and dairy selectionRecombined, caseinate and heat-stable dairy systems that tolerate sterilization where fresh cream would not.
- Stabiliser systemGums and salts that keep solids suspended and stop the soup separating across an 18-month shelf life.
- Solid-to-liquid ratioFixed as a specification, because it drives heat penetration, drained weight and how the soup eats.
- Particulate sizeCapped so the slowest-heating vegetable piece reaches lethality without turning the rest to purée.
- pH and salt balanceAdjusted to protect protein stability and to tune where the seasoning lands after the cycle.
- Concentration and dilutionConcentrating the soup changes viscosity, heat transfer and the schedule — and often the economics of shipping it.
Packaging
Formats it can ship in
Pack formats we run
- Retort pouchFlat or stand-up, single and multi-serve — Fast heat transfer, ideal for thin and medium-body soups
- CanTinplate and aluminium, seamed — The established route for retail soup, robust in distribution
- Glass jarTwist-off and lug closures — Premium broths and concentrates, product visible on shelf
- Semi-rigid bowlCPET or PP with lidding film — Eat-from-pack single-serve soups
Heat penetration and seal integrity studies settle which pack suits your specific product. We also run packaging material testing on its own, for converters validating a retortable film, tray or closure.
What we need from you
- Fill weight and drained weight
- What goes in the pack, and what the consumer sees when it comes out
- Solid-to-liquid ratio
- The single biggest driver of heat penetration in a filled pack
- Largest particulate dimension
- Decides where the cold spot sits and how long the hold runs
- Target pH
- Determines whether the product is low-acid or acidified
- Viscosity, hot and cold
- Governs whether heat moves by convection or conduction
- Target shelf life and market
- Sets the validation and documentation the project has to produce
Who we develop for
Brands, manufacturers and exporters
Soups & Broths are developed here for the people who have to put them on a shelf — from first formulation through to a process a manufacturer can run. That includes retail soups, catering sauce and soup formats for foodservice, and concentrated stock base and soup base products sold to manufacturers and commissary kitchens in bulk supply, by the litre or in totes.
Food start-ups and entrepreneurs
A recipe that works at home or in a cloud kitchen, and no idea whether it survives thermal processing at all.
Exporters and importers
Ambient meals for diaspora and overseas retail markets, needing a validated scheduled process and the documentation an importing authority will ask to see.
Cloud kitchens, QSR and HORECA
Turning a menu item into a packaged product, so a dish that sells in one kitchen can be produced centrally and shipped ambient.
Private label and contract manufacturing buyers
Sourcing a white-label or private-label product, and needing the formulation and the process proven before committing a co-packer.
NPD, R&D and QA teams
Inside an established manufacturer, needing pilot capacity and thermal process expertise without tying up a commercial line.
The technical side
Thermal processing, in the terms your QA team will use
If you are briefing an R&D, NPD or quality assurance team, these are the concepts a retort soup and broth project is actually built on. They are also the terms an importer, an auditor or a co-manufacturer will expect to see in your file.
Process and science
- Commercial sterility
- The state a low-acid product has to reach: no microorganisms capable of growing under normal ambient storage. It is a process outcome, not an ingredient.
- F₀ — sterilization value
- Integrated process lethality, expressed as equivalent minutes at 121.1 °C (250 °F) using the z-value of 10 °C (18 °F) conventionally assumed for Clostridium botulinum spores. For process establishment it is evaluated at the slowest-heating point of the container. The number your scheduled process is built around.
- D-value and z-value
- How fast a target organism dies at a given temperature, and how that death rate changes with temperature. Together they turn a time–temperature curve into a lethality figure.
- Clostridium botulinum
- The target organism for low-acid canned foods. Every low-acid ready-meal process is designed against it, which is why a curry is treated differently from an acidified sauce.
- Cold spot
- The slowest-heating point inside the container — usually the centre of the largest particulate rather than the sauce around it.
- Come-up time
- How long the retort takes to reach hold temperature. Product keeps changing throughout it, which is why the state at fill and the state on the shelf are different targets.
- Low-acid versus acidified
- Above pH 4.6 a product is low-acid and needs a full sterilization process. Acidifying below it, where the recipe allows, moves the product to a milder process.
- Overpressure
- Compressed air applied on top of the process medium so pouches, semi-rigid trays and glass do not burst as entrapped headspace air expands and product vapour pressure rises. Rigid metal cans in saturated-steam still retorts generally do not need it; the same cans in water immersion, steam-air or rotary systems often do.
- Static and agitating retorts
- Static retorts hold the pack still. Agitation — end-over-end, axial or reciprocating — moves the contents and speeds heat transfer in products that heat by convection, where a mobile liquid phase and a headspace bubble can travel as the container turns. It does little for a solid pack that heats by conduction. Rotational speed is itself a critical factor in the scheduled process.
- Water immersion, steam-air and spray
- The three common heating media. Each transfers heat differently, so a schedule validated in one is not automatically valid in another.
- Water activity (aw)
- Free water available to microorganisms. 21 CFR 113.3 defines a low-acid food as one with finished equilibrium pH greater than 4.6 and aw greater than 0.85, so a product at or below 0.85 sits outside Part 113. Above both thresholds the product needs a scheduled process delivering commercial sterility — which can be reached by heat, by acidification under Part 114, or by controlling water activity combined with heat.
- Scheduled process
- The validated combination of time, temperature, pressure and fill that delivers commercial sterility for one specific product in one specific pack.
- Temperature distribution study
- Mapping the retort itself before the product goes in — finding the slowest-heating position in the vessel across a full load. It is a separate study from heat penetration, and it comes first.
- Heat penetration study
- Thermocouples placed at the cold spot of the pack, through a full cycle, in the slowest-heating position the distribution study identified. This is what the scheduled process is calculated from.
- Incubation testing
- Finished packs held at elevated temperature for a set period and then examined for swelling, pH shift and spoilage — the check that the process actually delivered commercial sterility. 21 CFR 113 defines incubation but does not mandate it; US canned meat and poultry must be incubated under 9 CFR 431.10 at 95 ± 5 °F for not less than 10 days.
- Challenge testing
- Deliberately inoculating product with a target or surrogate organism to prove the process controls it. Used when the formulation sits near a critical limit rather than comfortably inside it.
- Process deviation
- A cycle that ran short, cool or interrupted. The batch is not automatically lost — but the deviation has to be evaluated against the scheduled process and the decision documented before it can be released.
Standards and compliance
- FSSAIIndian licensing, product standards and labelling for packaged foods
- Codex AlimentariusThe international reference code of practice for low-acid and acidified canned foods
- HACCP and GMPThe food safety management and manufacturing systems the process sits inside
- US 21 CFR 113 and 114Thermally processed low-acid and acidified foods, for exporters shipping to the United States
- EU and UK requirementsFood information and labelling rules, and the documentation an importer will request
- Nutrition and labellingNutritional analysis, allergen declarations and the claims the pack can legally carry
- ISO 22000 and FSSC 22000Food safety management certification, and the scheme an international buyer or retailer will usually ask to see
- US FDA registration and process filingFood Canning Establishment (FCE) registration on Form FDA 2541, then process filing on Form 2541d (low-acid retorted), 2541e (acidified), 2541f (water activity or formulation control) or 2541g (low-acid aseptic), each carrying a Submission Identifier (SID) — required under 21 CFR 108.25 and 108.35 before low-acid or acidified product enters the United States, with process control to 21 CFR 113 and 114
- APEDA registrationExport registration for scheduled products, alongside the health and phytosanitary certificates a destination market asks for
- Halal and KosherCertification routes where the destination market or the buyer requires them
Thermal sterilization is only half the work. The other half is the documentation — the scheduled process, the heat penetration data, the microbiological results and the shelf-life study — that lets a manufacturer run the product and an authority clear it.
Questions
Soups & Broths, specifically
Can you retort a cream soup without it curdling?
Yes, but not with fresh cream and nothing else. It needs a heat-stable dairy or plant protein system, a stabiliser package and usually a pH adjustment. The trials establish which combination holds for your recipe.
Why do the solids in our soup sink?
Because nothing is holding them. A suspension system sized for the particulate load and the viscosity after processing — not before it — is what keeps a soup looking the same at month twelve as at month one.
Is a concentrate better than a ready-to-heat soup?
Commercially, often yes: you ship less water and the pack is smaller. Technically it is a different product, because concentration changes viscosity and therefore heat penetration, so it needs its own scheduled process.
Can a bone broth stay clear after retorting?
Clarity is achievable but it depends on the raw material, the extraction and the filtration before filling. Protein and fat that are still in suspension at fill will show up as cloud or sediment on the shelf.
How long does a pilot take?
Typically three to eight weeks from first consultation to a validated pilot batch, depending on how much reformulation the product needs and whether shelf-life work is included.
What batch size do you run?
Our pilot retort takes 6 kg per cycle, roughly 20 pouches at 300 g. That is enough to answer whether the product survives the process across several pack formats, run a sensory panel and pull shelf-life samples.
Do you offer contract manufacturing or private label?
Our retort is a pilot and development unit, not a commercial line. We prove the product and the process, then hand the validated scheduled process and documentation to a co-packer, co-manufacturer or toll manufacturer — ours or yours — for private-label or white-label production at volume.
Can you supply on a private label or contract manufacturing basis?
Our retort in Chennai is a pilot and development unit rather than a commercial line. We prove the product and the process, then transfer the validated scheduled process and documentation for production at volume — private label, white label, own label, OEM, third party manufacturing, toll manufacturing, co-packing or co-manufacturing, with your co-packer or one we introduce. Bulk supply arrangements, pack formats and minimum order quantities are agreed with the manufacturing partner rather than set by us.
What does an export file need?
It depends on the destination. The United States regulates thermally processed low-acid foods under 21 CFR 113 and acidified foods under 21 CFR 114, with an establishment registration and a scheduled process filed with the USFDA; the European Union applies food information and labelling under Regulation (EU) 1169/2011, with EFSA governing claims; India works to FSSAI licensing and product standards. We produce the scheduled process, heat penetration data, shelf life testing results and the certificate of analysis that sit underneath all three.
More on the process, the machine and the full category list on the pilot retort processing page
Related retort categories:
Next step
Tell us what you are trying to make shelf-stable
Send the product, the pack you have in mind and the market you are selling into. We will tell you what the retort is likely to do to it, what would need to change, and what the pilot would need to cover — through to the scale-up and technology transfer a co-packer, co-manufacturer or your own plant would need to take it to volume.
- 1Send the formulationEven a bench-scale recipe and a photo is enough to start.
- 2We come back within two working daysWith what the cycle will do to it and where the risk sits.
- 3You get a scoped quotePriced on the work the product actually needs.
Let’s create something Innovative and Delicious together
Food Research Lab strives for excellence in new Food, Beverage and Nutraceutical Product Research and Development by offering cutting edge scientific analysis and expertise.
