h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

It doesn't matter how long you cook a steak - after you've seared both sides for 10-20 seconds, consider it safe to eat, this is assuming that the cut of meat was purchased from a respectable butcher or market.

The nice thing about steaks, even the "blue" kind, is that microbes only live on the surface; just beneath the surface, the steak is sterile. So for those of you that choose to cook your steak more than you would like because you fear food poisoning, stop worrying.

BUT!!! don't ever eat hamburger patties cooked any less than well done. What goes for steaks doesn't go for burgers. A hamburger pattie is made with GROUND meat - which means the surface flora have been mixed throughout the patty and searing does NOT kill the microbes that have now been dispersed throughout the burger. Many E.coli 0157:H7 (killer E.coli) involve burgers that have not been cooked thoroughly.

If you like your burger patties less than well done, it's safest to make them yourself! Take a good cut of steak, sear it on both sides, than grind it and grill it on the same day. You'll find that the seared flavor makes the center of the pattie taste better, yet it remains as you like it, rare.