A speciality coffee flavour note across London.
Rubber in speciality coffee presents as a low, slightly acrid note reminiscent of new tyres or latex, sitting beneath the cup's primary flavours rather than dominating them. In small amounts it can read as a savoury, almost meaty depth, though at higher intensities it becomes unwelcome and off-putting to most palates. It is typically associated with certain sulphur-containing compounds produced during fermentation or with robusta-influenced blends, and can also emerge from roasting defects or inconsistent green bean storage.
This note is often found in coffees from origins where natural or wet-hulled processing is common, such as Sumatra and other Indonesian islands, where the extended contact between bean and organic matter during processing can encourage the development of earthy, rubbery compounds. Robusta-containing blends typically carry a higher likelihood of this note, as the species naturally contains more of the chemical precursors associated with it. Coffees that have experienced post-harvest handling issues, regardless of origin, can also present rubbery characteristics as a marker of stress during drying or storage.
When scanning a bag or menu, tasting notes referencing "earthy", "tobacco", or "leather" in Indonesian or wet-hulled coffees may sometimes accompany a mild rubbery quality, though producers who seek this character out rarely label it explicitly. It tends to be most apparent in immersion brew methods such as French press or cupping, where the full body of the coffee allows lower-register flavour compounds to surface more clearly. Drinkers who find this note interesting rather than off-putting may find it worth exploring alongside other earthy characteristics in aged or wet-hulled Sumatran varieties.
Take our 60-second flavour quiz and discover roasts across London that are aligned with your palate — including ones carrying rubber notes.