The present invention is a Ca(OH).sub.2 particle composition and a method of making the composition, the composition consisting essentially of dried calcium hydroxide particles having a moisture content of less than 2 percent by weight of the total composition, a specific surface area greater than 30 m.sup.2 /g, a total nitrogen desorption pore volume of at least 0.1 cm.sup.3 /g, and a CO.sub.2 content of less than 2 percent by weight of the total composition, the aforementioned particles being in the form of a mixture comprising first fraction of particles having a size of less than 32 micrometers and a second fraction of particles of a size greater than 32 micrometers, the weight percent of the second fraction ranging from 20 to 50 percent, the aforementioned particles having a nitrogen desorption pore volume consisting of pores with a diameter ranging from 100 to 400 Angstroms.