What is a representative sample in green coffee trading?

A representative sample - sometimes called a stocklot sample - is a sample drawn directly from a specific quantity of coffee held at a named location. Unlike a type sample, which shows a general style, a representative sample corresponds to an actual parcel: this is the coffee, this is where it is, this is what it tastes like.

To be genuinely representative, the sample should be drawn from multiple bags within the lot rather than a single bag - the aim being to give an accurate, holistic picture of the coffee rather than cherry-picking the best material. Standards for how this is done vary between warehouses and exporters, which is worth bearing in mind when evaluating samples from suppliers you don't know well.

Representative samples are the foundation of honest green coffee trading. An offer sample is a representative sample offered with a specific lot available to buy. A pre-shipment sample (PSS) is a representative sample drawn just before export. Both depend on the sampling being done properly to be meaningful. When a sample doesn't match the landed coffee, poor representative sampling is often part of the explanation.