Why does it take a couple of hours before you start feeling ill from food poisoning?

Germs require time. Sevreal variables can delay the onset of symptoms in food poisoning. The amount of germs ingested may vary & stomach acid may destroy them before they can get thru. The host body may also be tolerate the toxin up to a point. Any left over germs require time to make enough toxin in the gut to trigger symptoms. Occasionally the germs have made enough toxin before intake that symptoms come sooner.