Late winter is the point in the storage season where a lot of good work can be undone quickly. For months, managers fight for uniform temperatures, steady airflow, controlled moisture, and calm biological behaviour. Then shipping pressure ramps up, doors start opening more often, conveyors start running, and the pile transitions from “stored product” to “handled product.”
That transition is where bruising, blackspot, shatter bruising, skinning, and handling-related defects often take hold – sometimes invisibly at first. By the time a receiver flags a load or a customer complaint arrives, the damage is already done.
This article is the next installment in Potato News Today’s Storage Season Essentials series. It follows the airflow and warm-spell pieces by focusing on what happens when potatoes start moving again: how to warm, move, and load tubers without creating preventable quality losses and claims.
Why late-winter handling risk spikes
Late winter handling risk increases for three simple reasons:
- tubers are often colder, and cold tubers bruise more easily
- the crop may be drier than earlier in the season, increasing impact sensitivity
- shipping urgency can push operations toward faster movement and more drops
Add outside weather swings, door openings, and the temptation to rush warm-up steps, and the stage is set for avoidable damage.
A reality check: most “shipping problems” begin before the truck arrives
It is tempting to treat claims as a trucking issue or a grading issue. In reality, many late-winter defects are created before loading even begins:
- pulling from the wrong zone of the pile (coldest, driest, or highest-risk corner)
- not tempering long enough – or tempering too aggressively and creating condensation
- running conveyors and drops at summer speeds during winter pulp temperatures
- not checking for early warning signs (odour, localized dampness, subtle breakdown)
If you want fewer claims, the core discipline is simple: treat shipping as a controlled operation, not an emergency.
Pulp temperature: the number that matters most
Air temperature is useful, but pulp temperature is what predicts bruise risk.
A potato can be sitting in a building that feels “warm enough” to people, yet the tuber core can still be cold – especially if the pile has been stable and cold for weeks.
Practical handling principle:
- the colder the tuber, the higher the bruise risk under impact and drop stress
- the more dehydrated or stressed the tuber, the more fragile it becomes
- the more abrupt the temperature transition, the greater the risk of condensation and surface issues
A disciplined operation checks pulp temperature in the zone being pulled, not just the room temperature near the door.
The warm-up trap: tempering that creates condensation
Warming potatoes for shipping is often necessary, but warming can backfire if it creates sweating on tubers or building surfaces.
The risk rises when:
- warm, moist air is introduced rapidly to a cold pile
- doors are opened frequently, bringing in damp outside air
- tempering is rushed and uneven (warming the surface while the core remains cold)
Best practice mindset:
- temper for movement, but do it with stability in mind
- avoid creating moisture deposition on tubers, equipment surfaces, and floor zones
- verify conditions with quick inspections rather than assuming success
Choosing where to pull from: start with the most stable zone
Not all parts of a pile are equal in late winter. Some zones are colder, drier, more vulnerable to airflow weakness, or more likely to have been affected by condensation events.
A sensible pulling strategy prioritizes:
- zones with the most stable temperature history
- zones that respond evenly to ventilation
- areas away from chronic corner issues and door influence zones
- lots with known risk factors flagged early (wet harvest, soil-heavy loads, bruising-prone varieties)
If the same corner produces problems year after year, late winter is not the time to pretend it will behave differently.
Handling anatomy: where bruises and damage are born
Late winter damage tends to come from predictable locations:
- drops from elevator transitions
- sharp conveyor turns
- transfer points with excessive speed
- poorly padded impacts
- accumulating tubers that create pressure bruising
- sudden stops and starts that create impacts and abrasion
The point is not to eliminate movement – it’s to reduce unnecessary impact energy.
Practical risk reducers:
- minimize drop heights wherever possible
- slow conveyors and transfer points during cold handling
- use cushioning and appropriate chutes where feasible
- reduce “tuber-on-metal” impacts
- keep flow steady rather than stop-start surges
If you only fix three things, fix the three biggest impact points in your system.
Dryness and bruise sensitivity: the late-winter double hit
As the season progresses, potatoes can become more susceptible to bruising and skinning if they have lost moisture or if skin condition has changed.
Signals that dryness may be contributing:
- more scuffing and skinning at normal conveyor speeds
- increased shatter bruising during colder periods
- surface feel that looks dry or “tired” compared to earlier months
- noticeable weight loss patterns linked to long fan runs during very dry air events
This is where storage management and shipping management meet: what you did with ventilation and humidity earlier in the season can affect how tubers behave on the line now.
Crew discipline: winter shipping requires a different pace
A common late-winter failure is operating the line like it’s September.
Winter shipping requires:
- slower speeds
- fewer drops
- clearer stop-and-check routines
- more deliberate decisions about which pile zones to pull from
- stronger documentation to track lot behaviour and outcomes
The most effective winter shipping programs are not the fastest. They are the most consistent.
A practical pre-load inspection routine
Before the line starts, do a quick risk scan:
- check the zone being pulled for temperature (pulp if possible)
- check for localized odour
- check for signs of condensation or dampness near walls and corners
- confirm the pile zone has been stable and responsive
- check equipment impact points and make winter adjustments (pads, drops, speed)
- confirm crew understands the day’s lot priorities and caution points
A five-minute inspection can prevent a week of claims conversations.
Shipping-day logging: how to learn season over season
If you don’t log what happened on shipping day, you can’t improve outcomes. At minimum, record:
- date, outside conditions, and door opening frequency notes
- pile zone pulled and pulp temperature (or best available proxy)
- equipment settings (speeds, notable adjustments)
- any odour or moisture observations
- any unusual behaviour during handling (increased bruising signs, skinning)
- destination and intended use (fresh vs processing vs seed)
When a claim arises later, your records become your clarity.
Common late-winter scenarios and what to do
A cold snap hits and shipping continues
What happens: bruise risk rises sharply, especially if tubers are pulled from cold zones or moved quickly.
What to do: slow the system, reduce drops, prioritize tempering, check pulp temperature, and pull from the most stable zone.
Tempering creates sweating on tubers or equipment
What happens: moisture deposition increases breakdown risk and can worsen surface condition and handling flow.
What to do: reduce aggressive warm-air exposure, re-check moisture risk logic, increase inspections, and avoid sudden transitions.
Bruising spikes unexpectedly during a normal run
What happens: often tied to colder pulp temps, dryness, or one major impact point being worse than assumed.
What to do: stop and identify the top impact points immediately, slow speeds, reduce drops, and confirm pulp temperature.
A receiver flags blackspot or bruising after arrival
What happens: impact damage may have been created at handling, loading, or during transport vibration – and only becomes visible later.
What to do: review equipment settings and impact points, confirm pulp temperature management, and use shipping logs to pinpoint the lot and conditions.
One-page Late-Winter Shipping and Handling Checklist
| Phase | Checklist items (tick as you go) | Notes / readings |
|---|---|---|
| Before movement | ☐ Identify pile zone to pull (most stable / responsive zone) ☐ Check tuber temperature in that zone (pulp if possible) ☐ Quick odour scan (localized “off” odours flagged) ☐ Check for condensation evidence (walls, corners, top-of-pile near walls) ☐ Confirm today’s intent (fresh / processing / seed) and risk priorities | |
| Tempering / warm-up | ☐ Temper with stability in mind (avoid rapid warm, moist air exposure) ☐ Avoid sweating events (watch for fogging, dampness, surface sheen) ☐ Verify outcomes with a walk-through after warm-up adjustments ☐ Document what changed and why | |
| Equipment setup | ☐ Reduce conveyor speed for winter handling ☐ Minimize drop heights at transfer points ☐ Cushion high-impact points (where feasible) ☐ Avoid stop-start surges and pile-ups on belts ☐ Confirm the three biggest impact points have been addressed | |
| During loading | ☐ Monitor for increased skinning or visible damage cues ☐ Re-check temperature if conditions shift (doors open, cold snap) ☐ Watch for moisture deposition on equipment or tubers ☐ Keep flow steady – avoid sudden starts/stops ☐ Pause if bruising signals rise and adjust immediately | |
| Shipping log | ☐ Date and outside conditions noted ☐ Pile zone pulled recorded ☐ Tuber temperature recorded (pulp if possible) ☐ Equipment settings recorded (speeds / major adjustments) ☐ Any odour / moisture notes recorded ☐ Destination and use recorded |
Takeaway
Late-winter shipping is where the storage season stops being a systems management exercise and becomes a human-and-hardware exercise. You can run an excellent storage program for months – stable temperatures, disciplined ventilation, good moisture control, strong airflow uniformity – and still lose quality quickly if the crop is moved too cold, handled too fast, or warmed up in a way that triggers sweating. In practical terms, shipping is not a separate phase from storage. It is the final test of whether storage management choices truly protected tuber integrity.
The most consistent operations treat shipping as a controlled protocol, not a scramble. That starts with lot selection and zone selection: pulling from the most stable areas of the pile, avoiding chronic corner zones, and refusing to ignore early warning cues like localized odour or dampness. It continues with temperature discipline: understanding that pulp temperature is what governs bruise sensitivity, and that room air temperature can mislead crews into thinking the crop is “ready.”
It also means adjusting handling to winter reality – slowing conveyors, reducing drop heights, controlling surges, and focusing attention on the three biggest impact points where most damage is actually created.
Just as importantly, late-winter shipping demands moisture awareness. Tempering is often necessary, but it has to be done without importing damp air or creating condensation on tubers and equipment. A brief sweating event can undo a lot of good storage work by creating localized wetness that invites breakdown – and by degrading surface condition in ways that complicate handling.
The safest approach is deliberate, incremental change, verified by short inspections and backed by clear documentation.
Finally, if there is one habit that separates “we think we did everything right” from “we can prove what happened,” it is shipping-day logging. A basic record of pile zone, tuber temperature, equipment settings, outside conditions, and observations creates accountability, supports learning season over season, and protects the operation when questions arise later.
In late winter, the winning strategy is not speed. It is repeatable control – because control is what protects quality, protects margins, and keeps the team out of the claim cycle.
Auteur : Lukie Pieterse, editor/publisher Potato News Today
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