Fundamentals
Simmer vs. boil: the 30 degrees that change everything
"Bring to a boil, then reduce to a simmer" is the most common instruction in cooking, and one of the least precise. Here's what the words actually mean in degrees, and why the difference matters.
The bands, defined
| Stage | Temp (°F) | What you see | Use for |
|---|---|---|---|
| Poach | 160–180 | Steam wisps, no bubbles | Eggs, fish, chicken |
| Bare simmer | 180–195 | Occasional bubble breaks surface | Stocks, braises, beans |
| Simmer | 195–205 | Steady small bubbles | Soups, sauces, grains |
| Boil | 212 | Vigorous rolling bubbles | Pasta, blanching, reduction |
Why stocks demand a bare simmer
A boiled stock turns cloudy and greasy: the agitation emulsifies fat and impurities into the liquid instead of letting them rise for skimming. At a bare simmer, the same ingredients yield a clear, clean stock. The ingredients are identical. Only the temperature differs.
Why beans split and sauces break
Rolling boils physically batter delicate food. Beans burst their skins, dumplings disintegrate, and dairy- or egg-based sauces curdle as proteins seize above ~180°F. The fix is never "stir more". It's holding the pot 15–20 degrees cooler.
The burner problem
Gas and electric burners don't hold a liquid temperature; they deliver constant power. As the liquid reduces, the same flame drives the temperature up: a pot that started at a simmer is boiling an hour later. This is why long-cooked dishes need re-checking, and why "set it and forget it" fails on a stovetop.