Production batch (lot)
A batch is a defined quantity of product made or harvested under comparable conditions and marked with a single number. That number is the key used to reconstruct where the raw material came from and to identify the customers who received it if anything has to be recalled.
The number is created at several points in the chain. On the farm it usually starts at harvest and ties together the field or part of it, the date and the variety. In a plant it appears at raw material intake and then again in production, because one batch of finished product often combines several deliveries. At a buying station the number travels with the weighbridge ticket and the sample result from the quality lab.
How wide to cut a batch is a trade-off. A wide batch, say a full day of production, means less work marking things up. A narrow one, limited to a shift, a tank or a pallet, reduces how much product a recall would cover. When a complaint comes in from a retail chain, that difference decides whether you pull one pallet or a week of production.
The most common trap is losing the number during repacking or transhipment. Produce arrives in a crate with a handwritten card, moves into different packaging and gets a new number without anyone recording what it came from. From that point the trail backwards is broken even though the paperwork looks right. Machine-readable marking helps, meaning a GS1 label carrying the batch number and an SSCC on the pallet, because scanning removes the chance of keying the number in wrong.
You will recognise the topic if answering "which field did this come from" means going through several days of dispatch notes, and if during a recall test nobody can quickly produce the list of customers who received one batch.