The Food Lab: Better Home Cooking Through Science

by J. Kenji López-Alt

32°F (0°C): The freezing point of water (or the melting point of ice). • 130°F (52°C): Medium-rare steak. Also the temperature at which most bacteria begin to die, though it can take upward of 2 hours to safely sterilize food at this temperature. • 150°F (64°C): Medium-well steak. Egg yolks begin to harden, egg whites are opaque but still jelly-like. Fish proteins will tighten to the point that white albumin will be forced out, giving fish like salmon an unappealing layer of congealed proteins. After about 3 minutes at this temperature, bacteria experience a 7 log reduction—which means that only 1 bacteria will remain for every million that were initially there). • 160° to 180°F (71° to 82°C): Well-done steak. Egg proteins fully coagulate (this is the temperature to which most custard- or egg-based batters are cooked to set them fully). Bacteria experience a 7 log reduction within 1 second. • 212°F (100°C): The boiling point of water (or the condensation point of steam).