Blue cheese achieves its unique appearance and smell by the addition of Penicillium roqueforti. Bloomy or brie-style cheeses gain their easily recognizable fluffy white rind from the presence of Penicillium camemberti. This mold helps to soften the cheese, but it also releases lots of ammonia in the process. The real devil of a stinker has always been washed-rind cheese. Here, the cheesemaker rubs the outside of the cheese (usually with a brine solution) that ultimately results in the growth of Brevibacterium linens, which gives the cheese a characteristic orange color on the surface. This bacterium is fast acting and as such seems to produce the greatest stink of all. Well beyond ammonia, washed-rind cheeses can have sulfurous overtones and will often achieve – to the delight of aficionados – the smell of feet. This is not surprising because it is, in fact, the same bacteria at work in both. Yum!