I will admit that I'm late to discover the power of not throwing all that cloudy cooking water down the drain once my pasta is cooked. It may not look too appealing, but this stuff is the key to a successful sauce and to a beautiful pasta dish. Are you with me here or have you already embraced the liquid gold that is pasta water?
What is pasta water?
It is literally the water that you used to cook your pasta. Pasta contains starch and when you cook it, some of that starchiness escapes out into the water – that’s why it looks white and murky by the time your pasta has cooked.
So what's so special about the pasta water?
Here's the science bit ... Today’s lesson is about emulsification. I’ve touched on it before in this post about Chocolate Fudge Popsicles but here, we are using the fact that the starchy, salty water that is left after the pasta is cooked, is the perfect emulsifier to make a beautifully silky sauce to serve with your pasta. The emulsifier qualities help the water in your pasta to combine with the oil in the sauce, creating a smooth, luscious sauce, worthy of your Italian Nonna. It also acts as a thickening agent and the salt that you added to the water (you did, didn’t you?) will provide a little boost of seasoning.
How to use the water from your pasta -
- When you’ve rescued your cooking water from the pan, you can add it gradually to your sauce and stir to combine. Don’t be alarmed if it thins out the sauce at first – it will thicken back up magically as the starch is absorbed into the sauce.
- If you are using your pasta water to revitalise leftover pasta, add it slowly and stir it through to combine.
- It also works really well for loosening pesto – especially when you want to be able to drizzle it.
How to make this as easy as possible?
- Don’t use too much water for cooking the pasta – You may have been told to use LOADS of water to cook your pasta. I've found that the less water you use, the 'starchier' the cooking water becomes and the better it does its job. The smaller amount of water means that you will need to give the pasta a couple of stirs while it’s cooking to prevent it from sticking – but I think the resulting super-starchy water makes it worth the effort.
- Give yourself a physical reminder to save the water - Put something (anything really - I use a ladle) in the colander as a prompt to remind you to rescue some of the cooking water before it disappears down the sink.
- Store any of the cooking water that you don’t use in the fridge – It’s useful for breathing new life into leftover pasta and will keep in a sealed container for 2-3 days. My fridge always seems to contain a jar of the mysterious looking milky liquid!
And one final thought on the topic of pasta…
Don't rinse your pasta once it’s cooked and you’ve drained off the cooking water! The starch on the surface of the pasta works in the same way as the starch you've added to the sauce through the addition of the cooking water — it helps the sauce stick to the pasta. If you rinse the pasta, you're rinsing away that helpful starch.