Aluminum salt containing high percentage of Al30

A method of making an aluminum chlorohydrate salt comprising:

• I) heating an aqueous solution containing a first aluminum salt and a buffer, wherein the first aluminum salt is present in a molar concentration of at least 0.75M, wherein the buffer is an amino acid or betaine and a molar ratio of buffer to aluminum is at least 0.1:1, at a temperature of 50° C. to 100° C. for a period of time of 1 hour to 6 hours to obtain a first aluminum salt solution;
• II) adding to the first aluminum salt solution an aqueous solution of an inorganic base to obtain a first aluminum chlorohydrate salt solution having an OH:Al molar ratio of at most 2.6:1 and a pH of 2 to 5;
• and
• III) heating the first aluminum chlorohydrate salt solution at a temperature of 50° C. to 100° C. for a period of time of at least 8 hours to obtain a second aluminum chlorohydrate salt solution containing an aluminum chlorohydrate salt having at least 50 mole % Al30 polyhydroxyoxoaluminum cation of all polyhydroxyoxoaluminum cations detectable by quantitative 27Al NMR within the aluminum chlorohydrate salt.