A 54-year-old asthmatic woman presented to hospital with a 10-day history of breathlessness. On examination, she was tachypnoeic with mild wheeze. She had preserved peak flows and was saturating at 100% on room air. Investigations revealed severe metabolic lactic acidosis. On further questioning, it transpired that she drank kombucha tea, which has been linked to lactic acidosis. She made a full recovery with supportive management and cessation of the tea.