165°F kills Salmonella in chicken the instant it gets there. But that's not the only route to safe chicken — held at 145°F instead, the same breast reaches the same kill, it just needs about eight and a half minutes to do it. Pasteurization was never one number. It's a trade between how hot you get and how long you hold it, and 165°F is just the version fast enough to need no clock at all.
Heat kills bacteria on a curve, not at a wall
Salmonella doesn't survive right up to 164°F and then die en masse at 165°F. It dies at every temperature above roughly 130°F, just at wildly different speeds — a curve that bacterial spores don't follow at all, which is why pasteurizing something and sterilizing it are two different jobs. Food scientists measure that speed with something called a D-value — the time a given temperature takes to knock a bacterial population down by 90 percent, one order of magnitude. Raise the temperature and the D-value shrinks toward nothing. Drop it and the D-value stretches out, sometimes by hours.
Getting chicken safe means clearing a target called a log reduction, usually around 6.5 to 7 logs — a ten-million-fold drop in live Salmonella. Stack enough D-values back to back at a low temperature and you reach that target the slow way. Hit a high enough temperature and you clear the whole thing in one instant. Same finish line, different pace.
What actually pasteurizes a chicken breast
| Temperature | Time to pasteurize |
|---|---|
| 145°F (62.8°C) | About 8.5 minutes |
| 150°F (65.6°C) | About 3 minutes |
| 160°F (71.1°C) | About 15 seconds |
| 165°F (73.9°C) | Instant |
These pairs sit behind USDA's own poultry guidance — they aren't a workaround to it. A thermometer reading of 145°F for a couple of seconds tells you nothing; it's the reading that gets restaurants flagged. Held at 145°F for the full eight and a half minutes, that same number is exactly as safe as 165°F, and the meat stays noticeably juicier, because less time gets spent past the point where its proteins seize up and squeeze out moisture.
This is what sous vide is actually doing
A sous vide bath holds meat at one fixed, low temperature for as long as it takes, which makes it the one common cooking method built to use the slow end of that table on purpose. Chicken sitting in a 150°F bath for twenty or thirty minutes isn't undercooked. It cleared its log reduction in the first three minutes and has been resting in safe, tender territory ever since. A skillet or an oven can't hold a temperature that precisely for that long, which is the real reason they lean on 165°F instead.
The same logic makes a raw-egg dish safe
An egg pasteurizes in its shell at 135°F (57°C), and it takes an hour and a quarter to get there. That is the trade pushed to its limit. The temperature is nowhere near enough to set a yolk, so nothing about the egg changes that you would notice beyond a slightly milky white — all the work is being done by the clock. Crack one afterwards and it whisks into a Caesar dressing or a chocolate mousse like any other egg. The risk in those dishes was never about doneness. It was about whether the egg had ever spent time at temperature, and almost none of them have.