The invention proposes a method for the production of a porous powder product containing a microorganism, from a liquid concentrate comprising at least one liquid microorganism culture and a carrier composition, the carrier composition comprising at least one carbohydrate and at least one protein, the method comprising the steps of: i) preparing the liquid concentrate to have both a temperature of between and 40° C. and a viscosity greater than 150 mPa·s； ii) injecting a food grade gas into the prepared concentrate at a pressure greater than 0.3 MPa to intimately incorporate the gas into the liquid concentrate and form a stable foam with a density of between about 0.6 to about 1.2 kg/l； iii) conveying the foam to an atomizing device wherein the pressure of the foam is reduced from 0.3 MPa to atmospheric pressure to provide a partially dried product； and iv) exposing the partially dried product to a drying media to reduce both the moisture content to less than 5% moisture and the water activity to less than 0.25 Aw, when measured at 20° C., and to provide the porous powder product, wherein the temperature of the porous powder product in step (iv) does not exceed 50° C.
