Well-seasoned water is the foundation of every delicious pasta dish. These days, you’d be hard-pressed to find a pasta recipe that doesn’t instruct you to salt the cooking water, but beyond vaguely invoking the sea, few of them bother to tell you how much salt is enough.
Ocean salinity is a known quantity — about 3.5 per cent on average — but recipes rarely extrapolate it into actual measurements. Seawater contains roughly 35g of dissolved salt per litre, and even though tap water contains some salt, that’s about what you’d need to add to emulate the briny deep.
If 35g sounds like a lot, it is: Two tablespoons of table salt per litre of water, to be exact.
As anyone who’s accidentally swallowed a gulp or two of real seawater can tell you, 35g per litre is way too much salt — even though most of it goes down the drain. If that’s the case, why is seawater the benchmark for pasta water seasoning?
Maybe it’s because most people don’t have a strong enough taste memory of seawater to accurately replicate it; they just know it’s pretty salty. Instructing cooks to aim for something “as salty as the sea” ensures not just that they’re adding a perceptible amount of salt, but that they’re actually bothering to taste the water before dumping in the pasta.
Salting to taste is a crucial culinary skill, but slurping boiling-hot salt water from a tasting spoon kind of sucks. This is where guidelines come in handy. I like estimating salt quantities based on the size of the pot I’m using rather than per litre of water because it requires less arithmetic.
One heaping tablespoon of table salt is perfect for a mostly-full 3 or 4L saucepan, and I’ve found that my 7.5L stock pot can handle as much as a quarter cup. These quantities also apply to ground sea salt.
Of course, the exact amount of salt depends on the volume of your pot and the dish you’re making, especially if you plan on using the pasta water to pull the sauce together. Penne puttanesca will probably need less salt than, say, spaghetti aglio e olio. Use your best judgement — you can always add more.