Traceability is often treated as a document you produce for an audit. In practice it is a property of how you record work: either each step points to the step before it, or it does not, and no report written afterwards can create a link that was never captured.
The chain, link by link
The grape intake is the first link, and the only one that connects wine to land. It carries the harvest year, the date, the producer, the parcel or variety, the kilos and the reception readings taken at the dock.
The pre-press work — destemming, crushing — records what was done to the grapes before the press. Kilos are not consumed here; the link matters because treatment of the fruit is part of the wine's story.
The pressing run is where solid becomes liquid, and the most important link in the chain. It records the inputs, the output fractions and the destination vessels, and it consumes the kilos it used. From this point every litre has a parent expressed in kilos.
The LOT is what the chain actually tracks. A LOT is a quantity of must or wine with an identity that survives movement: it changes vessel, it loses litres to lees, it receives treatments, and it keeps its code and its parents throughout.
Movements — transfers, splits, blends, consolidations — are the links most often lost on paper. A split creates a child LOT that names its parent. A blend creates a new LOT that names several parents. Read backwards, these are exactly the branches an investigation follows.
Additions and analyses attach to the LOT with their dose, the volume they were calculated on and the purchase lot the product came from — which is what turns "we fined it" into a defensible statement.
The bottling closes the chain. Litres leave the wine LOTs, a bottling lot code is created, and the finished-goods stock inherits it. The code on the label is the entry point back through every link above.
Why the strict rules exist
Systems that let you do anything produce chains you cannot read. That is why a well-designed record refuses to merge wine from two different batches inside a routine transfer, and asks you to record a blend instead: a blend names its parents, a silent merge erases them. It is also why bottled stock is calculated from movements rather than typed — a stock figure someone overwrote is a broken link in disguise.
What good traceability gives you beyond compliance
Compliance is the floor. The same chain answers the questions winemakers actually ask: which grower's fruit ended up in the tank that fermented best, what was added to the wine that showed a fault, how much of a vintage is still in bulk. And when a customer asks about a bottle, the answer is one lookup rather than a reconstruction.