Advice on pasta? Really? It’s not that hard. No, it’s not, and really, I’m quite happy with the pasta I already make. Well, everyone eats it, don’t they? And what could I be missing? I know how to boil water, add salt, taste it to see if it’s cooked. What could a cookbook possibly teach me about cooking pasta?

I was browsing through Rachel Roddy’s excellent Roman cookbook ‘Five Quarters’, one of my Christmas books, and came across the inevitable chapter on pasta. Just as I was considering, as I often do, why I don’t make fresh pasta that often, and trying to remember where in the kitchen the pasta maker will clamp to the counter, I saw a page about cooking pasta where she confesses that her husband thought she was making pasta all wrong, and insisted on giving her some pointers.
I thought I knew what I was talking about when it came to pasta, at least as much as the next non-Italian, but then so did she. So I paused to read the directions, and then I put them straight to work.

The advice she repeats is likely things you have heard before, but I think it makes a real difference to actually follow them. So for once I weighed out the pasta, (200g for the two of us) and then measured the water into the pan (2 litres, using the marks on the inside of the pan) and then weighed out the salt (20g). That’s quite a lot more salt than I was expecting. I know that the water is supposed to be well seasoned, but somehow I was never tempted to take a sip of the rapidly boiling water, and made do with a generous shake of the Saxa. I turned out to have the amount of water about right, but needed probably twice as much salt – about a tablespoon for a two litre pan of water.

Then I cooked the pasta until the chalky centre had gone (go any further and my husband can’t tolerate it – something I attribute to his being taught to like pasta by a Roman). I saved a ramekin of pasta water – something I do sometimes, but not consistently. I warmed serving bowls and a large bowl, to mix the pasta in. I added grated parmesan to the pasta first, followed by the ragu, and a dribble of pasta water. Then I tossed the whole thing together and served it.

I find it hard to dislike pasta with homemade ragu, but I do think that this one had a more rounded flavour, and was better for following these directions.

Even when you think you know all there is to know about even simple cooking directions, someone can persuade you to think again, and bring something new to the party.

Why does this advice work?

When you cook dried pasta, water is absorbed into the pasta and swells and softens the starch. At the same time, some of the surface starch lifts off and dissolves into the water. When you boil pasta in too little water, it takes a long time to come back to the boil (as the cold pasta drops the temperature of the water a long way), and the concentration of the starch in the water is quite high. The starch isn’t really a problem: after all, restaurant kitchens reuse their pasta water for many servings of pasta at a time. But the real problem is that the pasta doesn’t have enough room to move about and can start to stick together in the pan as it cooks. This can mean it cooks unevenly.

Undersalting often makes the difference between good restaurant food and home cooking. It’s easy to assume that a recipe isn’t good, or that something is just a bit underwhelming, when a bit of salt can make all the difference. Because the pasta absorbs a lot of water, properly salting the water allows the pasta itself to be seasoned well, and tossing it with parmesan before the sauce also helps this process. When each bite of pasta is salted well, the taste is very different.

Finally, much has been written about using pasta water in the sauce. The starch left in the water helps add some gloss to the sauce. The extra liquid dilutes the sauce a little and helps it to cling to every groove and ridge on the pasta, something that’s particularly important when you’re using good pasta, made with bronze dies so it has a good craggy edge to it.

Finally, Harold McGee has tried breaking all the rules and cooking pasta in too little cold water – it sort-of works, but is not approved by Italian cooks!