---
id: KB-AL-018
url: https://app.codecontract.io/help/food-and-beverage/bulk-grain-when-the-silo-mixes
idioma: en
categoria: sector-alimentacion
subcategoria: cereales
audiencia: usuario
nivel: avanzado
actualizado: 2026-08-13
tambienEn: [es]
relacionados: [KB-AL-015, KB-GL-020, KB-AL-024]
citadoPor: [KB-AL-025]
---

# 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._

**Responde a:** bulk grain traceability · how a batch is defined in a silo · incoming grain analysis · mixing harvests in the same silo

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.

> [!WARNING]
> 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.

> [!NOTE]
> 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.

## Ejemplos

**A lorry with a problem discharges onto twenty tonnes and the whole silo has to be held.**

- Tests on entry, before discharging onto existing product

→ The problem stays inside one lorry instead of multiplying twentyfold.

**Product is transferred between two silos to make room and nothing is recorded.**

- Keeps a transfer log with date, source and destination

→ The two silos stop sharing a history nobody can reconstruct.

**The batch is «the whole silo since it was emptied», and that is six weeks.**

- Defines when a batch closes, and actually closes it

→ An incident is bounded to days of filling rather than a month and a half.

**Every lorry that arrives changes what is in the silo.**

- Records each intake with its origin and date

→ The silo's contents are explicable.

**A client asks about one specific outbound movement.**

- Checks which intakes made up the silo at the time

→ You answer with what was there that day.

**Unloading happens into the wrong silo.**

- Records the location on unloading

→ The error is caught before mixing.