Pasta School

Why should you save pasta water?

Understand how starch in pasta water helps oil, cheese and sauce cling, plus how much to reserve and when to add it.

Short answer

Pasta water contains released starch. Added while tossing, it helps fat and water stay together and gives sauce a glossy, clingy texture.

Pasta water is not magic and it is not thickener in the same way as flour. Its value comes from a small amount of starch and the fact that it is already hot and seasoned.

Reserve more than you think you need. Nobody has ever improved dinner by pouring the last useful mug down the sink.

How emulsions form

Fat and water naturally separate. Agitation breaks fat into tiny droplets, while starch helps keep those droplets suspended long enough to coat the pasta.

How much to add

Start with one or two tablespoons for cheese sauces and larger splashes for tomato sauces. Toss, watch the texture and add more only when needed.

At a glance
SauceHow to use pasta water
Olive oilAdd while tossing over medium heat
CheeseCool slightly, then add off heat
TomatoUse to loosen during the final toss
PestoMix into pesto away from direct heat

Keep in mind

  • Reserve at least 250 ml before draining.
  • Very fresh pasta releases less starch than dried pasta.
Use the lesson

Keep cooking.