Pasta contains many starch molecules which start to unravel and escape when put into hot water. If starch molecules from two different pieces of pasta get tangled, they’ll make those two bits join together. To stop this use loads of water when you cook pasta, and boil it vigorously - that will help stop the pasta bits sticking together. The foam that you see when you boil pasta is formed by starch molecules that have escaped, forming networks, as if trying to thicken the water. Occasional stirring also helps to keep the pasta pieces separate.
Salt or Oil?
Should you add salt or oil to pasta that’s cooking? Salt flavours the pasta a little and will increase the temperature that the water boils at by a few degrees, so the pasta will cook faster. So use it if you like, but it’s not crucial. If you add oil to the boiling water, it will coat each pasta piece with a thin layer when you pour the pasta out into a colander. The idea is that this stops the pasta pieces from sticking together, but if you used plenty of water in the first place, that shouldn’t be a problem really. But if you’re keeping the pasta for a while, rather than serving immediately (eg if you’re keeping some of the pasta for, say, a pasta salad), the layer of oil helps to keep the pasta bits from sticking together later on.
Pasta e fagioli
Preparation time less than 30 mins
Cooking time 10 to 30 mins
2 tbsp olive oil
2 cloves garlic, peeled and finely chopped
1 carrot, diced
2 potatoes, peeled and diced
1 celery stick, diced
1 large tomato, peeled, de-seeded and diced
2 pint/1.2 litre chicken stock
375g/13oz cannellini or borlotti beans from a can, rinsed and drained
200g/7oz munnezzaglia or tubettini pasta
1 small chilli pepper, finely chopped
2 fresh basil leaves
salt and freshly ground pepper
1 tbsp virgin olive oil
1. Heat the oil and fry the garlic for one minute. Add the vegetables and toss well. Pour in the stock, bring to the boil and simmer for five minutes.
2. Add half of the beans. Mash the remaining beans in a bowl with the back of a fork, then add to the stock. Add the pasta, chilli and basil.
3. Cook gently for another eight minutes, stirring from time to time to prevent the mixture sticking.
4. Skim the soup to remove any scum. Season, to taste, with salt and freshly ground black pepper and serve in bowls with a drizzle of virgin olive oil on top.