Warm berries overload the shipper
Strawberries should enter the package already chilled. Packing warm fruit leads to fast condensation and a short holding time.
Strawberries Cold Chain
Strawberries need a cold route, but the packout cannot rely on heavy frozen packs alone. The goal is to start with pre-cooled fruit, hold a stable chilled range, protect clamshells from pressure, and keep the pack dry enough for retail acceptance.
Product Risk
The right package has to protect the product’s arrival quality, not only keep the logger cold. The risk points below determine the insulation choice, coolant placement, pre-cooling requirement, and receiving checks.
Strawberries should enter the package already chilled. Packing warm fruit leads to fast condensation and a short holding time.
Small impacts or top-load pressure can appear as dark marks after delivery.
Wet pads, wet labels, or sweating clamshells can make a cold shipment look poorly handled.
Gel packs and dividers should not seal clamshell vents or create a cold wet surface against fruit.
Route-Based Recommendation
These are practical starting points for sample planning. Final coolant weight and insulation thickness should be verified with the actual payload, shipper, route, and receiving standard.
| Shipment condition | Recommended Tempk package | Starting coolant direction | Coolant position | What to validate |
|---|---|---|---|---|
| Same-day local delivery 8-18h route, ambient below 22 C, short dock exposure |
Insulated carton liner or compact EPS shipper, vented clamshells, absorbent pad, and rigid outer carton | About 0.4-0.8 kg total conditioned gel packs for a 1-3 kg chilled payload. Use the calculator for actual payload, box size, and ambient profile. | Side-wall gel pack or top-corner placement with corrugated divider; keep coolant off the clamshell lid. | Arrival fruit temperature, clamshell dryness, berry firmness, leak marks, and remaining coolant state |
| Overnight parcel route 18-36h route, ambient 22-30 C, depot and van handling |
EPP or EPS insulated box, liner bag, absorbent layer, fixed clamshell stack, and stronger outer carton | About 0.8-1.5 kg total gel packs or chilled PCM for a small parcel. Increase only after checking cold-spot risk. | Two side positions or side-plus-top with a buffer layer; place logger near the product center or warm side. | Warmest payload point, cold spots near coolant, condensation, clamshell pressure, and berry bruising |
| Hot-weather or delay-prone route 30-35 C ambient, 36-48h risk, weekend hold possible |
Thicker EPP/EPS shipper, higher insulation margin, moisture barrier, and route logger | About 1.5-2.5 kg total coolant or a chilled PCM system for a small parcel. Hard frozen bricks need full product buffering. | Perimeter coolant layout with dividers on all product-facing sides; keep weight away from the top of the stack. | Peak temperature, freeze contact risk, pad wetness, carton strength, and receiving appearance |
Coolant mass is a starting point, not a guarantee. Adjust by product temperature at packing, payload weight, clamshell or carton count, shipper size, insulation material, coolant conditioning, route duration, ambient profile, and receiving checks. More ice can create cold spots, moisture, or pressure damage when the product support is wrong.
Packout Structure
For produce, inner pack control is just as important as insulation. Start with the product condition and pack format, then add coolant and insulation around it.
Packing Process
A stronger shipper helps, but product temperature, pack stability, and coolant separation usually decide whether the delivery is accepted.
Pre-cool strawberries, clamshells, pads, and inner packaging so the box is not fighting avoidable heat load.
Choose gel packs or PCM by route target. Avoid hard frozen contact unless a divider has been tested.
Fill empty space, keep clamshells level, and prevent gel packs from pressing into the fruit stack.
Check temperature, firmness, bruising, leak, pad wetness, clamshell condition, and carton strength.
When to Change the Design
Keep the thermal target, then improve absorbent material, liner design, vent clearance, or coolant conditioning.
Reduce stack pressure, add dividers, limit headspace, and keep coolant weight off clamshells.
Increase insulation margin, use a larger shipper-to-payload ratio, adjust coolant mass, or shorten the shipping window.
Related Resources
Share berry temperature at packing, clamshell size, payload weight, route duration, ambient range, and receiving checks. Tempk can help choose insulation, gel pack layout, and validation steps.
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