I have carried various organic matters including, in fact, coffee (although ground) in my hand luggage on BA flights and never had any issues with security or BA.
My husband travels with his own coffee, coffee dripper and whatever else he considers necessary for 'his' cup of coffee every flight he takes and he even annoyingly does DIY coffee on long haul flights from time to time. He has had no issues whatsoever except for the envious look from other passengers...
Originally Posted by
corporate-wage-slave
CWS travels with a coffee + tea stash, sugar, water heater and mug in the all-in-one Skypak bag. No problems anywhere, including Australia, New Zealand and the USA, though I always mention it if asked if I have any food products on me. One never knows where one will end up, but I do know where I'll end up without caffeine in the morning. LHR and LIS won't be a problem.
Do you carry a standalone heating element rather than a kettle?
I saw one in the US ages ago but I haven't seen one around anywhere else. Do tell me if you know where to get the 240v one (the one I bought in the US was 110v).