How mozzarella is made

Mozzarella is hot curd kneaded and pulled like taffy until it turns stringy.

stations: 7
things upstream: 5
raw sources: 3
steps from the ground: 2

The short version

Milk is curdled, the curd is cut and drained, and then it rests until it is acidic enough to stretch. Workers or machines knead the curd in very hot water until it turns smooth and elastic, pull off portions and shape them into balls. The balls are chilled and held in brine or whey.

Curdle the milk

Milk is warmed, soured with starter bacteria and set with rennet. It rests until it has gelled into a single soft block.

Goes in
Pasteurized milk
Cut the curd small

Wires slice the gel into small pieces, which lets whey drain out of each one. Smaller pieces mean a drier cheese.

1 to 1.5 cm pieces
Stir and drain

Stirring and gentle heat shrink the curds and push out whey. Whey drains away and the curds are collected into a solid mass.
Rest until stretchy

The curd mass sits while acid keeps building. Once the pH reaches the right window, the proteins will pull into long strands instead of crumbling.

pH 5.2 to 5.5
Knead in hot water

Curd is steeped in a bath of hot whey or water and then worked until it is smooth, shiny and stringy. Hot water pulls calcium out of the protein network, so the strands slide and stretch.

95 °C for buffalo mozzarella
Pull off and shape

A thick strand of the hot paste is drawn out and chopped off in portions, which is where the name comes from. Each portion is rolled into a ball or other shape.
Chill and brine

Fresh balls soak in salty water or whey and are packed in liquid. Low-moisture mozzarella for pizza is made drier and keeps far longer than the wet kind.

Goes in
Table salt

End of the lineMozzarella Next it goes into frozen pizza.

Worth repeating

Fresh mozzarella was traditionally eaten the day it was made, but shredded low-moisture mozzarella can be sold with a shelf life of up to six months.
Stretching removes a lot of calcium, so mozzarella has about 40 percent less calcium than cheddar.