Italians defend their cuisine in a notorious – and legitimate – way, as evidenced by the frequent debates over the appropriate toppings for pizza or the choice of pasta to use with a bolognese ragu.
It is therefore not surprising that when an Italian physicist, winner of a Nobel Prize, gave advice on how to cook pasta to perfection, which seemed to challenge every method the country’s cooks had used for centuries, he sparked a lively controversy.
Professor Giorgio Parisi – who received the Nobel Prize in Physics 2021 for “his discovery of the interplay between disorder and fluctuations in physical systems, from the atomic scale to the planetary scale” – suggested that putting out fire halfway through cooking the pastathen covering the pot and waiting for the residual heat from the water to finish the job, can help reduce the cost of cooking pasta.
To this, the Michelin-starred chef Antonello Colonna replied that this method made the pasta rubbery and that it could never be served in a gourmet restaurant like his. The controversy quickly spread through the media, with input from several food and science luminaries.
But for those of us at home trying to save money by cooking pasta, does Parisi’s method really pay off? And is it really that bad? Inspired by the idea of saving money, Nottingham Trent University students Mia and Ross took to the kitchen to cook pasta in a variety of ways, helping to clear up the issue.
What happens when you cook pasta?
First of all, we have to ask ourselves what really happens when we cook pasta. In the case of dry pasta, two processes usually take place in parallel. First, the water penetrates the pasta, rehydrating and softening it within ten minutes in boiling water. Then the pasta heats up, which causes the proteins to expand and make them edible.
The classic cooking method is to immerse 100 g of pasta in 1 liter of boiling water for ten to twelve minutes, depending on its thickness. The distribution of energy consumption is represented in the following graph, which can be converted into total cost by means of the information on the energy price and the efficiency of the cooker.
At today’s prices, the cost of cooking dry pasta on a ceramic hob is $0.21 per serving, $0.17 on an induction hob and $0.11 on a table. gas cooking. So, given our passion for pasta (for example, every person in the UK eating an average of one serving per week), we spend about $7,625,000 a week cooking pasta.
The graph clearly shows that around 60% of the energy is used to keep the water boiling. So anything that can be done to reduce the cooking time would have a huge effect on the overall cost. Parisi’s method of turning off the griddle halfway and letting the pasta cook in the residual heat cuts the cost of cooking in half, saving about $0.05. This method will be even more effective on ceramic hobs; unlike gas and induction, they take longer to cool down.
However, by separating the rehydration and heating processes, it is possible to further reduce the cost. Dry pasta can be fully rehydrated by making it first soak in cold water during two hours. This process requires no energy and saves an additional $0.05.
The pasta must then be plunged into boiling water to reheat it; and there too, there are other savings to be made. THE chiefsTHE bloggers and the scientists report that the quality of cooked pasta is not affected by the considerable reduction in the amount of water. We found that using half the water gave us perfect pasta, but reducing our use to one-third left us unsatisfied. Starch is released during cooking; if there is not enough water, it concentrates, leaving clumps of unevenly cooked pasta. However, stirring the pan regularly improves the result somewhat.
The graph shows that the second highest energy requirement is that needed to bring water to a boil. Again, further savings can be made here.
Turns out the pasta protein granules dissolve above 80°C ; it is therefore not necessary to bring the pan to a “heavy boil” at 100°C, as is often advised. A light simmer is enough to fully cook the pasta, saving an additional approximately $0.01.
We have also studied the possibility of using a microwave to heat the previously soaked pasta. These devices are very efficient at heating water, but in our experiments they produced the worst pasta of all. Do not try at home!
How to do it…and save money
The palm for most effective method of cooking dry pasta returns to the pre-soaking in cold water before cooking in a pan of water or simmering sauce for one to two minutes. Leaving the lid on the pan is another simple thing you can do. The addition of salt, although making only a minimal difference to the boiling point, improves the taste considerably.
We’re not all star chefs or Nobel Prize-winning physicists, but we can all make a difference in the way we cook to reduce our electricity bills while producing tasty food. Now it’s your turn to experiment with these methods until you find a combination that makes your cooking more economical while saving your pennies!
The author would like to thank his students Mia London and Ross Broadhurst for their assistance in compiling this research.