Food and beverage
Bulk grain: when the silo mixes
In bulk, the batch is not defined by the product but by the silo. And every lorry that arrives redefines what is inside.
With packaged product, every unit carries its batch on it. In bulk nothing carries anything: there is a silo holding twenty tonnes that arrived on six lorries from four different fields, and the seventh will unload on top of it this afternoon.
Bulk batch
Whatever you decide a batch is, normally by silo and filling period. It is not given by the product: define nothing and the batch becomes «the whole silo since it was last emptied», which is usually far too much.
The four decisions that determine everything
| Decision | Consequence |
|---|---|
| When a batch is closed | Defines how much is held if something fails |
| Whether deliveries are mixed | Every mix ties the fate of both together |
| What is analysed and when | Decides whether a problem shows on entry or on exit |
| What is kept per lorry | The only thing that lets you look backwards |
Important
**The rule governing bulk: every discharge onto existing product extends the batch both backwards and forwards.** If this afternoon's lorry brings a problem, it affects everything in the silo — and what left this morning came out of that same silo. Which is why the incoming analysis, before discharge, is not a formality: it is the only moment when a problem still fits inside one lorry.
What must be reconstructable
- 1
Which lorry discharged into which silo, and when
With times. It underpins everything else.
- 2
Who it came from and from what origin
Supplier and, where applicable, field or area.
- 3
What analysis was run on it and with what result
The lorry's, not only the silo's at the end.
- 4
And which despatch went to whom, from which silo
Without this nothing can be bounded going forward.
Watch out
The point that most often breaks traceability in practice: **transfers between silos**. Product is moved to make room, to blend qualities, or because a silo needs maintenance, and that operation is almost never recorded as carefully as an intake. From then on the two silos share a history and nobody knows it. A transfer log, even a notebook, is worth more than any other paper on the day something has to be bounded.
Worth knowing
Which controls, analyses and records grain destined for food or feed requires, and what limits apply to each contaminant, is set by food and feed rules. **Your adviser or quality manager settles that**; here we explain the organisational part that decides whether those controls are worth anything.
›Can I have one batch per silo?
That is the usual approach. What matters is deciding when it closes.
›Does every lorry need analysing?
It depends on the product and its destination. Testing on entry is what bounds it.
›What if I mix two years' harvests?
You can, but the resulting batch belongs to both. Write it down.
A real case
The situation
A lorry with a problem discharges onto twenty tonnes and the whole silo has to be held.
What you do
- Tests on entry, before discharging onto existing product
What you get
The problem stays inside one lorry instead of multiplying twentyfold.
The situation
Product is transferred between two silos to make room and nothing is recorded.
What you do
- Keeps a transfer log with date, source and destination
What you get
The two silos stop sharing a history nobody can reconstruct.
The situation
The batch is «the whole silo since it was emptied», and that is six weeks.
What you do
- Defines when a batch closes, and actually closes it
What you get
An incident is bounded to days of filling rather than a month and a half.
The situation
Every lorry that arrives changes what is in the silo.
What you do
- Records each intake with its origin and date
What you get
The silo's contents are explicable.
The situation
A client asks about one specific outbound movement.
What you do
- Checks which intakes made up the silo at the time
What you get
You answer with what was there that day.
The situation
Unloading happens into the wrong silo.
What you do
- Records the location on unloading
What you get
The error is caught before mixing.
This article answers
- bulk grain traceability
- how a batch is defined in a silo
- incoming grain analysis
- mixing harvests in the same silo