Cumulative patterns of Al release upon exhaustive leaching of E, Bh1 and Bh2 horizons of a podzol with M, 0.1Mand 0.01MKC1 were found to be markedly dependent upon KC1 concentration. Comparison ‘bulk’ extracts, equilibrated for both 16 h and 7 days, in most instances gave pH‐1/3pAl values which lay between 2.6 and 3.0, close to the value for the solubility of gibbsite. Results are discussed with reference to whether exchange processes or solubility processes controlled the extraction of Al. Differences in behaviour of the E horizon are related to a specific difference in its mineralogy.