Coffee Appreciation

I'm a bit too busy to dig up the relevant details but for my gaggia i know that the alu boiler is extremely sensitive to descaling solutions and you have to be extremely careful what you put in and how long for otherwise you'll knacker the insides of the boiler.

I think the main issue is for health reasons; if you use citric acid, then it forms aluminium citrate which can make you ill.

I believe tartaric acid is a safe option.