The influence of storage and production on the reactivity, i.e. the slaking rate of lime in water, has been investigated. It was found that hard burning of the lime during calcinations dramatically decreases its reactivity, as does storing under humid conditions. It also seemed that air rehydration during storage precedes recarbonation and there is evidence to show that the former process catalyses the latter one. (C) 2002 Elsevier Science Ltd. All rights reserved.