Mold fungi such as Penicillium, as spores or in vegetative states, are widely used in food applications for texturizing, flavoring, or protecting foodstuffs. These spores are usually produced on a solid medium in ``Roux flasks.'' However, to overcome the weaknesses of this process, the use of submerged liquid media has gained in importance over the past years. The aim of this paper is to review the recent progress in the field of production, in submerged liquid culture, of biomass and spores of mold fungi. The effect of the principal factors (medium composition, operating conditions, substrate, oxygen transfer, etc.) on the germination, growth, and sporulation phases are reported and discussed.