The spec sheet is the most important document in a food supply relationship and the one buyers read least carefully. It defines what you are buying in numbers, and together with the certificate of analysis it decides whether a delivered lot is acceptable or rejected. This guide explains how to read both documents line by line.
It is written for importers, quality managers, product developers and procurement teams buying fruit, vegetables, nuts, spices, juices and powders from Vietnam. Every figure below is an industry reference band rather than a promise. Confirm the numbers for the specific product on the supplier’s own documents before you contract.
What a spec sheet is and what a COA is
A specification, usually called a spec sheet, is a contractual description of a product. It states the parameters that matter, the limits for each, the test method and, where relevant, the sampling plan. It applies to every lot supplied under an agreement and it should be signed by both parties.
A certificate of analysis, universally shortened to COA, is the result for one specific lot. It reports what was measured on that lot, by which method, on which date, against the limits in the spec sheet. One is the rule, the other is the evidence, and a supply relationship needs both.
Think of the spec sheet as the contract and the COA as the receipt. The spec sheet is negotiated once and revised deliberately. The COA arrives with every delivery and is only meaningful because a spec sheet exists to read it against.
The failure mode is predictable. Buyers who accept a COA without an agreed specification have nothing to compare it against. Buyers who agree a specification but never look at the COA have a rule nobody checks. The discipline is simple: agree the spec sheet first, then check every COA against it.
What belongs on a complete spec sheet
A usable specification covers seven blocks. Anything missing from the list below tends to become the subject of a dispute later, because the parties fill the gap with different assumptions.
| Block | What it contains | Why it matters |
|---|---|---|
| Identity | Product name, botanical species, variety, origin, process | Prevents substitution and misclassification |
| Physical | Size, cut, colour, defects, foreign matter, drained weight | Defines what the buyer sees on arrival |
| Chemical | Brix, moisture, water activity, pH, acidity, ash | Controls stability and performance |
| Microbiological | Counts and pathogens with sample size and plan | Controls safety and shelf life |
| Contaminants | Pesticides, heavy metals, mycotoxins as applicable | Controls legal compliance in the market |
| Packaging and labelling | Pack format, net weight, coding, pallet pattern | Controls handling cost and traceability |
| Storage and shelf life | Temperature, humidity, stated life from production | Controls the commercial claim |
Add two administrative lines that buyers routinely omit: a version number with a date, and named signatories on both sides. A spec sheet without a version number cannot be managed, because nobody can prove which revision applied to a shipment that was ordered eight months ago.
Brix: what it measures and where it misleads
Brix is the measure of soluble solids in a solution, expressed in degrees and usually read on a refractometer with a temperature correction. For juices, concentrates, purees and canned fruit in syrup it is the headline number, because it drives sweetness, yield and, in several markets, the tariff line.
Two cautions belong on the brix line of a spec sheet. First, brix measures soluble solids rather than sugar specifically, so added acids and other soluble components affect the reading. Second, the point of measurement matters: brix of the fruit, brix of the syrup and brix of the drained product are three different numbers and a specification must say which one it means.
Because degrees brix approximate the percentage of soluble solids by weight, a concentrate quoted at 65% soluble solids carries roughly five times the solids of a single strength juice near 13%. That ratio, not the price per kilogram, is what determines cost in the finished beverage.
For concentrates the brix band determines dilution ratio and therefore the true cost per litre of finished beverage. Comparing two offers at different brix without normalising is the most common pricing error in juice buying. Details for specific products are on the NFC juices and purees hub and the passion fruit juice concentrate page.
Moisture and water activity on a spec sheet
Moisture is the total water in a product expressed as a percentage of weight, usually determined by oven drying to constant weight. Water activity, written as aw, measures how much of that water is available to support microbial growth, on a scale from zero to one.
They are not interchangeable, and a spec sheet for a dried product needs both. Two lots at the same moisture can behave completely differently if their water activity differs, because sugars and other solutes bind water and make it unavailable. Below roughly 0.6 aw most microbial growth stops, which is why that figure appears so often in dried fruit specifications.
Typical bands help calibrate a first draft. Soft dried fruit is commonly specified around 15% to 20% moisture, conventionally dried fruit around 13% to 18%, and freeze dried material around 2% to 5%. Frozen product is controlled by temperature rather than moisture and is normally specified at -18°C or colder throughout the chain. Confirm the band for the specific fruit and process, because these are orientation figures rather than contract values.
Moisture also has a commercial dimension, since water is sold by weight. A dried product at the top of its moisture band delivers less dry matter per kilogram than one at the bottom. Our detailed guide to dried fruit moisture and water activity covers the trade offs, and the soft dried fruits range shows how the parameters differ by product.
Microbiology: reading the numbers properly
The microbiological block is where a spec sheet most often becomes unenforceable, because limits get written without a method or a sampling plan. A number on its own is not a specification, and a microbiological line on a spec sheet without a stated sample weight is close to meaningless.
| Parameter | What it indicates | Specification must state |
|---|---|---|
| Total plate count | General hygiene and process control | Limit, method, incubation conditions |
| Yeasts and moulds | Spoilage risk in dried and chilled products | Limit and method |
| Enterobacteriaceae | Post-process contamination indicator | Limit and method |
| Escherichia coli | Faecal contamination indicator | Limit and method |
| Salmonella | Pathogen, zero tolerance | Absent in a stated sample weight |
| Listeria monocytogenes | Pathogen relevant to chilled and frozen | Absent or limit, stated sample weight |
Absent in 25 grams and absent in 10 grams are different requirements, and a supplier meeting the second is not meeting the first. Similarly, a two class or three class sampling plan changes what a single high result means. Reference methods from ISO and general hygiene principles from Codex Alimentarius are the usual sources for this block.
Pathogen results should also carry the laboratory name and accreditation status. A pathogen result from an unaccredited in-house laboratory is worth something for process control and very little in a dispute, which is why buyers of higher risk products require accredited third party testing on a stated frequency rather than on every lot.
Contaminants, residues and allergens
This block is driven by the destination market rather than by the supplier. Pesticide maximum residue levels, heavy metal limits and mycotoxin limits are set in law by the importing country, and they differ between markets for the same commodity.
- Pesticide residues, specified against the destination market’s own limits.
- Heavy metals such as lead and cadmium where the commodity and soil justify testing.
- Mycotoxins, notably aflatoxins in nuts and ochratoxin A in certain dried commodities.
- Process contaminants where a thermal step creates them.
- Allergen status, including cross contact risk from shared lines.
- Treatment declaration covering irradiation, fumigation and steam sterilisation.
- Genetic modification and origin declarations where the market requires them.
Put the destination market on the spec sheet explicitly, as a named line rather than as an assumption. A product compliant for one market may exceed a limit in another, and a specification that simply says compliant with applicable regulations gives you nothing to enforce. Aflatoxin control for nuts is covered in our guide to 캐슈넛 등급, and the nuts range lists the products concerned.
Sensory and physical lines that get left off the spec sheet
The chemical and microbiological blocks get attention because they produce numbers. The physical and sensory lines get skipped because they feel subjective, and that is precisely where most commercial complaints originate. Colour, size distribution, defect counts and texture drive customer perception far more than a moisture figure does.
Subjectivity is manageable if the specification defines the reference. Agree a colour range against a physical standard or an instrument reading, state a size distribution as percentages within named bands, and express defects as a maximum count or weight percentage per sample. Attach photographs of acceptable and unacceptable material to the spec sheet and reference them by name.
Drained weight deserves its own line for anything packed in liquid, and piece integrity deserves one for frozen and dried products that break in transit. Both are measurable, both affect the value the buyer receives, and both are frequently omitted. The differences between product formats are covered in our guide to IQF against block frozen fruit.
Adapting the spec sheet to the product category
A single template will not serve every category. The blocks stay the same but the parameters that carry weight change completely, and a specification that leaves the key line off is worse than no specification at all because it creates false confidence.
| 범주 | Parameters that carry the most weight | Often overlooked |
|---|---|---|
| IQF frozen fruit | Cut size, brix, defect count, temperature at loading | Free flow and glazing percentage |
| Dried and soft dried fruit | Moisture, water activity, added sugar, sulphite status | Piece size distribution |
| 견과류 | Grade, moisture, aflatoxin, broken and defect percentage | Free fatty acid and rancidity |
| Whole spices | Volatile oil, moisture, foreign matter, ash | Treatment status and mesh after grinding |
| Juice and concentrate | Brix, acidity, brix to acid ratio, colour | Pulp content and aseptic integrity |
| Powders and flours | Moisture, particle size, bulk density, solubility | Anti-caking agent declaration |
Build one master spec sheet template per category rather than per product, then populate it product by product. That keeps the review manageable and stops parameters being invented differently each time. The powders and flours and freeze dried ranges illustrate how far the relevant parameters diverge between categories.
How to read a COA against the spec sheet
Reading a certificate of analysis takes five minutes if you work through it in a fixed order. Doing it in a fixed order is what stops the important field from being skipped.
| Step | Check | Red flag |
|---|---|---|
| 1 | Lot code matches the delivery documents | Generic or missing lot reference |
| 2 | Production date and expiry are consistent | Expiry that implies a different shelf life |
| 3 | Every parameter on the spec sheet appears | Silently omitted parameters |
| 4 | Results are actual values, not simply pass | The word conforms with no number |
| 5 | Methods are named and match the specification | Method left blank or changed |
| 6 | Laboratory is identified with accreditation | No laboratory named at all |
| 7 | Document is signed and dated by a named person | Unsigned template |
The single most useful habit is refusing certificates that report conformity instead of values. A COA that says pass tells you only that someone applied a judgement. A COA that reports a moisture of a stated percentage against a stated maximum lets you see how close the lot ran to the limit, which is the information that predicts the next delivery.
Trend the data instead of filing it
Individual results answer whether one lot is acceptable. Trends answer whether a supplier is under control, and that is the more valuable question. Recording a handful of key parameters from every COA into a simple sheet costs minutes per delivery.
Watch for drift toward a limit, for variability increasing while the mean stays acceptable, and for results that cluster suspiciously close to a round number. All three are early signals that deserve a conversation before they become a rejection, and all three are invisible if certificates are filed unread.
Pick the five or six lines from the spec sheet that actually predict a problem for your process and trend only those. A trend file covering every parameter is abandoned within a quarter, while a short one survives.
Share the trend with the supplier. A producer who sees their own data plotted usually responds well, and the conversation shifts from blame after a failure to adjustment before one. This is the part of quality management that costs almost nothing and returns the most.
Retained samples, shelf life and disputes
Retained samples are the physical version of a COA. Both parties keep a sealed, labelled sample from each shipment, stored under the specified conditions, for a period that comfortably exceeds the shelf life. When a dispute arises, the retained samples are the only evidence that survives.
Shelf life claims on a spec sheet should be supported by data rather than by convention. A stated life implies storage conditions, so the specification has to state the temperature and humidity the claim assumes. A frozen product held above its specified temperature has not been supplied incorrectly if the buyer’s cold store failed, which is why our guide to cold chain and container loading matters to this document.
Write the dispute procedure into the agreement: who tests, at which laboratory, using which method, and who pays if the result confirms or contradicts the claim. Agreeing that in calm conditions takes one paragraph. Agreeing it during a dispute takes weeks.
Building a spec sheet for a new product
Start from the use, not from the supplier’s template. Write down what the product has to do in your process, then work backwards to the parameters that control it. A specification built this way is shorter and far more useful than one that copies every line a laboratory can measure.
- Define the application and the process step where the product is used.
- List the parameters that would cause a failure in that step if they moved.
- Set limits with tolerances, not single target values.
- Name a test method for every numeric limit.
- Add a sampling plan for anything measured on a lot basis.
- State the destination market so legal limits are anchored.
- Version the document, date it and have both parties sign it.
Then review the spec sheet annually and after any process change on either side. A specification that has not been touched in five years is usually describing a product that no longer exists. Full product detail across categories is on the products page, and packaging parameters are covered under packaging solutions.
Frequently asked questions about spec sheets and COAs
Should the buyer or the supplier write the spec sheet?
Either can draft it, but the buyer should define the parameters that matter to their process and the supplier should confirm which limits are achievable. A specification imposed without that dialogue tends to be quietly ignored, which is worse than not having one.
How often should a COA be issued?
Per lot for most food products, with the lot defined in the agreement. Some parameters are tested on every lot and others on a stated frequency, which is normal and should be written down rather than left to the supplier’s discretion.
What if a result is outside the specification?
Stop the delivery decision and follow the agreed procedure. Depending on the parameter, options include rejection, retesting by an agreed laboratory, concession acceptance with a price adjustment, or diversion to a different application. The route should be in the contract, not invented on the day.
Is an in-house laboratory result acceptable?
For routine process parameters, usually yes. For pathogens, contaminants and anything with legal limits, most buyers require an accredited third party laboratory at a stated frequency. Say which applies to which parameter on the spec sheet.
Do I need a separate spec sheet for each pack format?
Not necessarily, but the packaging block has to distinguish them. Where pack format changes shelf life or handling, a separate document is clearer. Where it does not, one specification with a packaging table is easier to maintain.
Bottom line on spec sheets and certificates of analysis
Agree a versioned, signed spec sheet before the first order, with a limit, a method and a sampling plan on every line and the destination market named. Read each COA in a fixed order, insist on actual values rather than the word conforms, and trend the results instead of filing them. Keep retained samples and write the dispute route into the contract. To request specifications or certificates for a specific product, browse the product range, read our guide to food safety certifications, see the frequently asked questions or contact Greatfoods.
Greatfoods is a manufacturer, exporter and supplier of high-quality food and beverage ingredients from Vietnam, including IQF frozen fruits and vegetables, dried and soft-dried fruit, nuts, spices and herbs, powders and flours, and NFC juices, purees and concentrates. We supply importers, distributors, foodservice operators and private-label brands worldwide with certified quality (HACCP, IFS, BRC, GLOBAL G.A.P., ISO, HALAL, SEDEX) and complete export documentation.