How do you make sure the bulk shipment matches the sample?
Approve a pre-shipment sample drawn from your packed lot, not the sample you tasted at the start. Lock the processing facility in the contract. Keep a retained sample from every container. Those three steps turn “the sample was great, the container wasn’t” from an argument into a measurement.
Every buyer of freeze-dried fruit has heard that story. With rambutan it is easy to happen, because the raw fruit changes through the season and every aril is peeled by hand. The answer is not to trust harder. It is to build the comparison into the order.
Why does bulk drift away from the first sample?
Three things move between the sample you approved and the container you receive.
The fruit changes. A development sample made in June from main-crop Rongrien fruit at 18–22° Brix is thick, sweet and pale blush. A lot run in January from off-season fruit at 15–16° Brix is thinner and sharper, and needs more fruit per finished kilo, as shown in how many kilos of fresh rambutan make 1 kg of freeze-dried. Both are honest rambutan; they are not the same product.
The facility changes. Some traders send a sample from one processor and fill the order at whichever plant has dryer space that week. Different drying cycles give different colour, crispness and fines.
The handling changes. A 200 g sample is peeled and goes straight into the freezer. A 5-tonne lot needs 30–35 tonnes of aril peeled by hand, and two things break at that scale:
- Pre-freezing delay. If peeled aril waits on the steel tables for 2–3 hours in tropical heat before it reaches the blast freezer, it weeps juice, starts to ferment at the edges and turns a dull, yellowish tan. Nothing in the dryer can reverse it.
- Dryer cold spots. A sample sits on one tray in the middle of the chamber and dries evenly. A commercial batch fills hundreds of trays top to bottom. Cut the cycle short to make a sailing, and trays in the colder corners come out with a chewy core at 5.0–5.5% moisture while the edge trays read 3.5%.
Both faults are invisible in a hand-picked sample and obvious in a container. That is why the sample that counts is the one drawn from the run itself.
A sample only protects you if it comes from the same fruit, the same facility and the same line as your container.
What is a pre-shipment sample, and what should you do with it?
The pre-shipment sample, or PSS, is drawn from your packed lot, after production and before the container is stuffed. It is the last chance to stop a lot that is wrong, and the reference for any claim after it lands.
The fear every QA manager has is the hand-picked sample: the best halves from the first carton, while the last cartons are full of fines. A FruitBuys PSS is a composite: portions drawn at random from the start, middle and end of each production day and from different pallet positions, combined before sealing. The fines level, moisture and colour in your pouch are the average of the whole container, not its best carton.
FruitBuys sends 100–200 g, split into two sealed foil pouches with desiccant, by express courier within 24–48 hours of packing. The two pouches have different jobs:
- Open the first pouch for your checks: bag integrity, weight of broken pieces and fines, colour against the approved sample, taste, and a split of ten halves to look for hard seed fragments in the cavity. Measure water activity, sealing the meter chamber within 60 seconds of cutting the foil.
- Keep the second pouch sealed. If a dispute ever reaches a laboratory, that unopened pouch is the evidence both sides accept.
Approve it in writing. That email or signed form becomes the contractual reference for the container: if the lot matches the PSS, it is accepted; if it does not, you have the proof.
What is retained, and for how long?
FruitBuys keeps a retained sample from every container lot, labelled with the same lot code as the cartons and the COA, and stored sealed in a temperature- and humidity-controlled room at ≤25 °C and ≤60% RH for the lot’s full shelf life. A sample left in a hot office would prove nothing after six months; one kept under the same conditions as the specification still shows exactly how the lot left Vietnam.
If a question comes up, the QC team in Vietnam opens the retained sample, measures aw and splits halves for a cavity check, and sends you the results and photos within 24 hours.
Your second PSS pouch and our retained sample together answer the question every dispute turns on: did the product change in transit and storage, or did it leave the facility that way? Without both, that question has no answer.
What does facility lock-in mean in the contract?
It means your rambutan is processed at one qualified facility, named in your contract, for the life of the contract. FruitBuys does not move your order to another plant to fill capacity.
If a change ever becomes necessary, for example a facility under maintenance at peak season, it happens only with prior written notice and re-approval of a new pre-shipment sample from the new facility. You also have audit access: your QA team, or an auditor you appoint, can visit the facility to see the sorting line, the dryers and the packing room.
Write those three lines into the purchase contract. They cost nothing to agree and they are the single best protection against sample-to-bulk drift.
What changes between seasons, and how do you plan for it?
The specification does not change: moisture ≤5.0%, water activity ≤0.30 and the same microbiological limits apply all year. What changes is the sensory profile, because the fruit changes.
Plan for it in three ways:
- Approve a reference sample for each season. A main-crop reference (May–August) and an off-season reference (December–March) give your QA team the right benchmark for each lot.
- Book volume against the main crop. Annual programmes contracted before May run mostly on main-crop fruit, which gives the most consistent colour and sweetness across your containers. In 2026, off-season fruit traded at about three times main-crop farm-gate levels, so the main-crop booking protects your cost as well as your recipe.
- Know what the COA cannot see. The COA measures moisture, aw and microbiology, and those stay inside spec all year. It does not measure wall thickness or the balance of sugar and acid. Main-crop fruit gives a thick aril, deep sweetness and a full floral note; off-season fruit is just as pale and crisp but finishes brighter and more tart. Keeping a main-crop and an off-season physical standard lets your R&D team adjust a chocolate or cereal recipe ahead of time, without changing the pack.
Trial or LCL first: what testing applies?
A trial order or an LCL shipment is the cheapest way to see the process before committing a container. It ships with the in-house release QC log for the batch (moisture, water activity and sensory) plus the latest third-party surveillance report.
If your QA team needs independent laboratory results on a trial volume, FruitBuys arranges them before dispatch at net laboratory cost, and credits the fee in full against your first container. Allow 3–5 working days for the lab work.
Full-container lots ship with a third-party COA for moisture, water activity, TPC, yeasts and moulds, E. coli and Salmonella. The limits and the arrival checks are set out in moisture, water activity and microbial limits for freeze-dried rambutan.
The five steps from sample to accepted container
| Step | What happens | Who acts | What it protects |
|---|---|---|---|
| 1. Development sample | Format and grade agreed; samples prepared in 3–5 working days | FruitBuys, your R&D | Right product choice |
| 2. Contract | Specification, named facility, change-control, audit access, season references | Both sides | No silent facility or spec change |
| 3. Pre-shipment sample | 100–200 g from the packed lot, two sealed pouches, couriered in 24–48 hours | FruitBuys sends, your QA approves in writing | The container matches what you approved |
| 4. Retained sample | Sealed sample kept from every lot for its full shelf life | FruitBuys | Evidence for any later question |
| 5. Arrival acceptance | Bag check, aw on three bags (meter sealed within 60 seconds), cavity check (the silky membrane and pale blush are natural), compare with PSS | Your QA | Fast, documented acceptance or claim |
Production for a 20ft runs 20–30 days after deposit, so the PSS step fits inside the normal timeline without delaying the sailing.
FAQ
What is a pre-shipment sample for freeze-dried rambutan?
A 100–200 g sample drawn from your packed lot before stuffing, sent in two sealed foil pouches within 24–48 hours. You test one and keep the other sealed as evidence.
How long is the retained sample kept?
For the full shelf life of each container lot, at ≤25 °C and ≤60% RH. Results on a query come back within 24 hours.
Can FruitBuys switch my order to another processing facility?
Not without prior written notice and your re-approval of a new pre-shipment sample. Your facility is named in the contract, and you have audit access.
Will off-season rambutan taste the same as main-crop fruit?
It meets the same specification but is thinner and sharper in taste. Approve a reference sample for each season, or book volume against the May–August main crop.
Should I start with a trial order?
A trial or LCL order is the lowest-risk way to see the process. Third-party testing on a trial is charged at net lab cost and credited in full against your first container.
Start with the right sample
Tell us your format, application and target season. We prepare development samples in 3–5 working days, then set up the pre-shipment sample and retained-sample routine for your first container. Product details are on the freeze-dried rambutan product page, and the full sourcing checklist is in what to check before buying freeze-dried rambutan in bulk.
