Food that makes people sick will often: smell slightly woody taste the same as normal taste sharp or bitter look bumpy with odd color

The answer to this question is: Look bumpy with odd color
Food that look bumpy with odd color often caused by the growth of Fungus on top of the food's surface.
This could make the food taste either sour or bitter. Eating such foods will often cause several problems such as fever and diarrhea.

The answer would be age 18.