Pouring pasta water down the sink? Italian nonnas beg you to stop – here’s the way to turn it into “liquid gold”

The hand shoots out faster than the steam. Just as you tilt the pot over the sink, an older voice cuts through the kitchen: “Ma sei matto? Don’t throw that away!” You freeze, pasta in the colander, cloudy water swirling dangerously close to the drain.

In many Italian homes, that starchy, slightly salty liquid is treated with the same respect as good olive oil. It isn’t waste; it’s an ingredient. Nonna doesn’t call it “pasta water”. She calls it oro liquido - liquid gold - because it quietly decides whether your spaghetti ends up silky and restaurant‑worthy… or sad and sticky.

Once you see what it can do, tipping it down the sink will feel like throwing flavour, money and effort away.

Why pasta water matters more than you think

On paper, pasta water looks unimpressive: water, salt, a bit of starch. In the pan, it behaves like a gentle cooking tool and a secret sauce in one.

As pasta boils, it releases starch into the water. Those tiny starch molecules act like natural emulsifiers, helping fat and water cling together instead of separating. Add a ladle of that cloudy water to a pan with olive oil, butter or cheese, and you get a glossy, smooth sauce rather than a greasy puddle.

Salt plays its part too. Properly seasoned pasta water (Italians often say it should be “salty like the sea”) lightly seasons both the pasta and whatever you splash it into. That means fewer extra pinches of salt later and a more even taste throughout the dish.

In simple terms: pasta water helps sauce grip the pasta, makes everything taste more coherent, and saves you from reaching for extra cream, butter or cheese just to get that silky texture.

How to cook and “bank” good pasta water

You don’t need special equipment to turn pasta water into liquid gold, but you do need a few habits.

• Salt at the right time. Add salt once the water is boiling, before the pasta goes in. A general guide is 1–1.5 tablespoons of salt for 4 litres of water, then adjust to your taste.
• Skip the oil. A slick of oil in the pot stops sauce sticking later. That might sound good; in practice it means nothing clings properly.
• Scoop before you drain. A minute or two before the pasta is perfectly cooked, dip in a heatproof jug or ladle and take out 1–2 cups (roughly 250–500 ml) of water.
• Use it hot. Warm pasta water emulsifies and thickens best. Keep the jug next to the hob and use it within the next 20–30 minutes.

If you’ve misjudged the timing and already drained the pot, all is not lost. If the colander is sitting over the saucepan, you can sometimes collect a little from the bottom. Otherwise, it’s a note for next time: pasta first, drain second, water never straight down the sink.

For short‑term “banking”, you can cool leftover pasta water and keep it in the fridge until the next day to enrich soups, doughs or beans. Beyond 24 hours, the flavour turns dull and slightly sour, so don’t hoard it for too long.

Turn pasta water into sauce that clings like in restaurants

The biggest shift nonnas and chefs wish more home cooks would make is this: stop finishing pasta in the colander, start finishing it in the pan with its sauce.

In Italy, this step even has a name: risottare la pasta - treating pasta a bit like risotto, finished together with its sauce and cooking liquid.

A simple routine works for almost every non‑baked pasta dish:

1. Undercook the pasta slightly. Drain it 1–2 minutes before the packet time while it’s still al dente in the centre.
2. Move it to the sauce pan. Your sauce (tomato, oil, butter, cheese, pesto) should already be hot in a wide pan.
3. Add a splash of pasta water. Start with 2–3 tablespoons.
4. Toss or stir vigorously. This friction helps starch, fat and water bind together.
5. Adjust with more water as needed. Add in small amounts until the sauce turns glossy and coats the pasta evenly, not soupy.

Some classic dishes where pasta water makes or breaks the plate:

• Cacio e pepe. Pecorino cheese and black pepper alone can clump into a gluey mess. Add hot pasta water gradually, whisking, and it becomes a creamy, peppery emulsion with no cream at all.
• Spaghetti aglio e olio. Garlic gently cooked in olive oil can sit heavy on the plate. A small ladle of pasta water turns it into a light, silky coating instead of a greasy film.
• Pesto pasta. Straight pesto can be thick and overwhelming. Loosen it in the pan with pasta water so it spreads thinly and evenly.

Think of pasta water as your “volume knob”: a way to control thickness, saltiness and creaminess with one ingredient.

Beyond pasta: everyday ways to use your “liquid gold”

Italian grandmothers rarely write recipes for pasta water. They just reach for it automatically whenever a pan looks a bit dry or a dish lacks softness.

Here are some of the ways they slip it into everyday cooking:

• Soups and minestrone. Replace part of the plain water or stock with pasta water for a subtly richer, silkier broth.
• Simmering vegetables. Boil green beans, broccoli or peas in leftover pasta water for extra seasoning and a hint of starch that helps glazes cling.
• Beans and lentils. Add a ladle to the pot towards the end of cooking. It rounds out the texture and seasons the pulses more gently than extra salt.
• Bread and pizza dough. Swap some (not all) of the liquid in your dough recipe with cooled pasta water. The salt and starch can give a slightly softer crumb.
• Reheating leftover pasta. Instead of microwaving it dry, warm it in a pan with a splash of pasta water and a little oil or butter to bring the sauce back to life.
• Deglazing pans. After cooking sausages, chicken or vegetables, use pasta water in place of plain water to scrape up browned bits and instantly start a light sauce.

A quick comparison can help you see when to reach for it:

Use case	When to add it	What it improves
Finishing pasta in sauce	Last 2–3 minutes in the pan	Cling, creaminess, seasoning
Soups and stews	During simmering	Body, subtle savouriness
Doughs and batters	When mixing liquids	Softness, gentle saltiness

One important note: because pasta water is salted, it is not ideal for watering plants or boiling very salty ingredients like some cured meats. In the kitchen, though, it’s surprisingly versatile.

Common mistakes that ruin your “liquid gold”

Not all pasta water is created equal. A few habits can quietly sabotage its magic.

• Water that is barely salted. Your pasta and sauce will taste flat, no matter how nicely they cling. If you’re nervous about salt, reduce it elsewhere in the dish, not in the pot.
• Water that is too salty. On the other side, if you’ve gone overboard, treat the pasta water as a concentrate: use smaller splashes and taste before adding any extra salt to sauces.
• Oil in the cooking water. That thin oil film stops starch mixing properly with sauce later. Keep the oil for the pan, not the pot.
• Letting it sit for hours. Starch sinks and the flavour dulls. If you must hold it, give it a stir before using and keep the timing tight.
• Relying on it to fix everything. Pasta water can’t rescue a burnt sauce or poor ingredients. It’s a booster, not a miracle.

If you’re cooking gluten‑free pasta, the water will still contain starch, but often less than traditional wheat pasta. It can still help emulsify, just don’t expect quite the same richness, and be cautious if anyone at the table is coeliac and you’re mixing it into other dishes.

A simple nonna‑approved routine for weeknight pasta

To make pasta water a habit rather than a one‑off trick, fold it into your weeknight rhythm. One straightforward pattern works with almost any sauce:

1. Put a large pot of water on and lay a heatproof jug or mug next to the hob to remind you to save some.
2. Salt the boiling water properly, then add your pasta.
3. While it cooks, prepare your sauce in a wide pan: garlic and oil, tomato, butter and herbs, pesto – whatever the recipe calls for.
4. Two minutes before the pasta is done, scoop out 1–2 cups of the pasta water.
5. Drain the pasta, move it straight into the sauce pan, and start tossing over medium heat.
6. Add pasta water a little at a time until the sauce looks glossy and coats every strand.
7. Taste for salt and pepper, adjust, and serve immediately - with a final tiny splash of pasta water in the pan if it starts to tighten before it hits the table.

Do this a few times and you’ll stop seeing pasta water as cloudy waste. It will become, quite naturally, the quiet ingredient that makes your simplest dinners feel that bit closer to an Italian kitchen.

FAQ:

• Can I store pasta water and use it the next day? Yes, you can cool it, pour it into a jar and keep it in the fridge for up to 24 hours. After that, the flavour and smell deteriorate, so it’s best to discard it and start fresh.
• Can I freeze pasta water? You can freeze it in small portions for adding to soups or stews, but it’s less effective for quick pan sauces once thawed. The starch can separate slightly, so stir well and set expectations accordingly.
• Does this work with all types of pasta? It works best with dried wheat pasta, which releases plenty of starch. Fresh egg pasta and gluten‑free varieties still give usable water, just usually a bit less potent.
• What if I forgot to salt the water? Unsalted pasta water still contains starch, so it can help emulsify, but it won’t bring any seasoning. Use it for texture, then adjust salt in the pan carefully.
• Is pasta water safe for people avoiding gluten? If someone must avoid gluten strictly (for coeliac disease, for example), pasta water from wheat pasta is not safe for them. In that case, either use gluten‑free pasta for everyone or keep their portion entirely separate, including the water used in the sauce.