AbstractA description is given of a wet‐sieving method for the determination of the water‐stable aggregates in a soil as an indication of the crumb structure. The method is rapid and convenient and gives results which are reproducible within about 1%. The method subjects the aggregates to more severe treatment than that associated with many other methods, but should give a reasonable measure of the stability of aggregates under field conditions. The relationships between the numerical results obtained by this and other methods are briefly discussed.