Samples, Supplier Audits and COAs: Qualifying a Vietnamese Food Supplier
A sample is only useful if it can be reproduced: tie it to a written specification, record exactly what it is, and keep part of it as the reference. Qualify the supplier on the facility that actually makes your product — its certificate scope, traceability and laboratory control — and read every COA against the specification, parameter by parameter.
Which kinds of samples are there?
Food samples come in five types, from a stock sample that shows the product family to a retained sample that settles later complaints.
| Sample | What it is | Use it to decide |
|---|---|---|
| Stock sample | Taken from existing production | Whether the product family suits you at all |
| Custom sample | Made to your specification or recipe | Whether the supplier can hit your target |
| Pre-production sample | Made to the approved recipe, in the final pack for private label | Final approval before the main run |
| Pre-shipment sample | Drawn from the lot being shipped | Whether the lot matches the approved sample |
| Retained sample | Kept by both parties from each approved lot | Settling questions and complaints later |
For private label, the pre-production sample in the finished pack is the one that matters: it is where recipe, packaging and label meet for the first time. In our private label coffee programme, for example, the buyer approves pre-production samples before the main run.
What does a sample cost, and who pays?
Sample cost depends on what is being sent. A stock sample by courier costs little; a custom sample means a production set-up; frozen samples need a suitable cold-chain arrangement, such as insulated packaging with dry ice accepted by the carrier; private label samples may need printed packaging mock-ups. Courier costs rise with distance and weight, and some destinations add import formalities even for samples.
Ask at the start which of these applies: the product, the packaging mock-ups, the courier, and any import charges at destination. Our sample route and any charges are confirmed per request.
What should a sample record capture?
A sample you cannot describe cannot be reproduced. Record for every sample:
- product, SKU and variant; origin and variety where relevant;
- the recipe or specification revision it was made to;
- lot code and production date;
- the key measured values: moisture and water activity, or Brix and acidity, cut size, colour;
- packaging used for the sample, and the storage conditions since dispatch;
- analytical results and photos;
- who approved it, on which date, and against which specification.
Keep part of the approved sample, stored as the product should be stored, for at least the product’s shelf life.
How should IQF and coffee samples be handled?
IQF fruit must arrive frozen to be judged. Agree with the carrier on insulated packaging and cooling sufficient to keep the sample frozen for the journey; if dry ice is used, confirm the applicable packing, marking and transport requirements. Check the product temperature on arrival, and judge it frozen first (free flow, clusters, frost) and thawed second (drip loss, texture, colour, flavour, Brix). Our IQF mango specification guide lists the checks.
Coffee samples need a clear purpose. Green coffee samples are roasted and cupped under an agreed protocol; roasted coffee samples carry a roast date and are judged at the right age; private label samples should come in the final bag with the valve and seal specified. Cup results are only comparable when everyone uses the same protocol.
How do you audit a supplier?
Start with documents, then check the site.
Documents first
- Certificates: the certified legal entity and site, the product and process scope, validity dates, and the certification body. A certificate that covers another site, or another product category, does not cover your product.
- The written specification and the HACCP plan for your product.
- Recent COAs, complaint records and corrective actions.
Then the site — in person, remotely or through a third-party auditor
- Food-safety system: hazard analysis and critical control points for your product, and the records that show they are monitored.
- Traceability: a trace test from a finished lot back to raw material and forward to customers, completed within hours.
- Incoming material control: supplier approval, acceptance checks, rejection records.
- Process control: temperatures, times and measurements at each critical step.
- Laboratory: what is tested in-house, what goes to an external laboratory, and whether that laboratory is accredited (ISO/IEC 17025).
- Foreign-body control: metal detection or X-ray, sieves, magnets, glass and hard-plastic policy.
- Allergen management, hygiene, pest control and staff training.
- Complaint handling and export document capability.
When you buy through an export company that coordinates several facilities, as we do for our product lines, ask which facility makes your product and qualify that facility. For US imports where FSVP applies, this evidence supports the importer’s documented risk assessment and supplier-verification activities; it is not the complete FSVP record; see our US import guide.
How do you read a certificate of analysis?
A COA should show results against your specification, not simply state that the product “passes”.
| COA field | What to check |
|---|---|
| Product and lot | Same product name, SKU and lot number as the invoice and cartons |
| Dates | Production date, and the date of analysis |
| Parameters | Every parameter your specification lists, not only the easy ones |
| Results | Actual values with units — “complies” alone is not a result |
| Limits | The specification limit printed next to each result |
| Methods | The method for each parameter, especially for moisture, Brix, sulphites and microbiology |
| Microbiology | Organism, unit (for example CFU/g) and sample size (for example “not detected in 25 g”) |
| Laboratory | In-house or external; accreditation for external results; signature |
Warning signs: identical results on every lot, missing methods, results without units, parameters that are not in your specification, and lot numbers that do not match the shipment. If a result is disputed, test the retained sample in an agreed independent laboratory with the method named in the contract.
Putting it together
A supplier is qualified when three things line up: a facility whose certificates and controls cover your product, an approved sample that is recorded and retained, and COAs that report the specification’s parameters for every lot. Our RFQ checklist covers the questions to ask before the first sample, and export documents by product type covers what should arrive with each shipment.
Related guides
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