One of the ideas for the game is that things on the ground and in containers can become infected with micro-organisms and these micro-organisms can spread to other things in the same container. Here is how it’s going to work:
Once a day, the game will select a limited amount of organic resources to get infected. It is assumed that there are spores in the air, so it doesn’t require a source in the same location or container. The game will also check which things are in the same containers with previously infected materials, and the higher the level of infection, the more likely it will spread. Infections start out small and are invisible in the beginning, but may become visible once the level gets high enough. Some bacteria, yeast and mold may be picky and only infect specific subtypes such as fruit, vegetables, grain products, meat or dairy.
Bacteria will cause things to decompose and eventually get purged from the game. Before that it will turn into nasty slimy goop and may attract insects, which in turn can potentially carry disease. Some molds and bacteria may cause vomiting, diarrhea or other health issues. However, there is also useful bacteria that can be used to make yogurt and buttermilk, and useful molds which can be used to make blue and white cheese.
Yeast can be used to ferment alcoholic beverages and raise dough. There’s probably going to be about a 10% chance of gaining a useful strain, but you can keep it alive by putting host materials in the same container. It’s yet undecided if a single pile can have more than one type of bacteria at a time. Increasing sugar and salt content protects mixtures against bacteria and mold.
Molds can be identified by color, but the catch is there will be visual twins to the useful molds, so you can mistakenly eat a harmful mold thinking it’s a good one. Some molds will be fuzzy while others have a dense structure.