Often, when we cook pasta, it happens that thewater overflows from the pan, ending up dirtying all the burners with white foam. Among the numerous tricks to solve the problem, there is also that of place a wooden ladle over the panwhich should prevent the water from overflowing. But does it really work?
Let’s start first by saying that, from a chemical point of view, the white foam it is due tostarch contained in pastagradually released during cooking is. It is precisely the starch that makes water more viscous, stabilizing the bubbles of steam which, at that point, do not explode immediately and form a thick layer that does not allow the steam to escape. In this way, the foam is able to grow with the heat, eventually overflowing.
Now, can a wooden spoon really stop this foam? Effectively the wood, being a good thermal insulator (and therefore a bad conductor of heat), remains colder than the water and the pan on which it is placed: when the bubbles they collide the ladle, these in turn cool down and the vapor present inside them condenses quickly, causing them to explode.
But this only happens if the foam is little and grows slowly, otherwise overflow is inevitable, given that the spoon does not physically block the water from flowing out. At the same time, if the wood remains on the pan for a long time, it will end up heating up anyway, losing this property.
In short, the most effective remedies to prevent the white foam from overflowing remain two:
- better adjust the ratio between water and pasta: if there is less water, then the starch concentration will be higher and consequently more foam will be created.
- adjust the intensity of the fire: if the flame is too high, many bubbles will be produced in a short time, which will end up coming out of the pan.
