Simmer stock, don't boil it
Bones are full of collagen. Held at 85 to 95°C (185 to 205°F) for 4 to 6 hours for chicken, or 8 to 12 for beef, collagen melts into gelatin. That gelatin makes stock silky and set when cold. The pot should barely bubble.
Boiling makes stock cloudy
A hard boil churns fat and loose protein into tiny droplets that stay suspended. You get murky, greasy stock instead of clear. Keep the heat low and skim the foam as it rises.
Start cold
Cover the bones with cold water and bring it up slowly. Proteins leak out gradually, clump and float up as foam you can skim. In already-boiling water they set fast into tiny bits that can stay suspended and cloud the stock.
Test yourself
Questions from the interactive lesson, with the answer and the why.
Your homemade stock sets like jelly in the fridge. What does that tell you?
Collagen melted into gelatin. Gelatin is what makes cold stock wobble and set.
True or false: A hard boil makes clearer stock than a gentle simmer.
False. Hard boiling churns fat and proteins into the liquid and clouds it.
What went wrong? You leave a stock at a rolling boil for three hours to save time. It turns out cloudy and greasy.
The boil was too hard. A bare simmer, with only a few lazy bubbles, keeps stock clear.
Fill the blank: Chicken stock needs about ___ hours at a bare simmer for good body.
Chicken stock needs about 4 to 6 hours at a bare simmer for good body. That is long enough to melt the collagen without dulling the flavor.
A gray foam builds on top of the pot in the first hour. What should you do?
Skim it off; it is clumped protein. Removing it keeps the stock clear.