A quick lesson on pH: pH 0 to 4 are highly acidic, pH 4 to 7 are mildly acidic, pH 7 is neutral, pH over 7 are alkaline. These brass utensils are made to be used with all alkaline, neutral, and mildly acidic substances, like dosa batter (pH 4-5) and most vegetables and fruits. It's worth noting that brass is reactive to highly acidic ingredients like lemon (pH of 2-3) or vinegar (pH of 2). With prolonged exposure to acidic substances, utensils will discolor with time. pH of salt is 7 - it is neutral, like water. So salt does not react with brass.