When it is dilute , it tastes sweet ; when it is a little concentrated , it tastes bitter ; when it is very concentrated , it tastes salty . This taste is because of the potassium ion . In a dilute aqueous solution , potassium bromide tastes sweet , at higher concentration it tastes bitter , and when most concentrated it tastes salty to humans ( these effects are due mainly to potassium ion ; sodium bromide merely tastes salty at all concentrations ) .