Cooking pasta with the heat turned off: effectiveness and limits

The  cooking of the pasta a heat turned off has conquered social media in recent years, promising significant energy savings. But does this alternative method really guarantee the same quality as the traditional cooking method with  live flame? A  experimental study conducted by Dr. L. De Lisio analyzed this technique by comparing it to conventional cooking and evaluating some objective qualitative parameters.

Methodology

The research adopted a rigorous approach to evaluate the quality of cooked pasta, analyzing three fundamental parameters:

• stickiness (the state of surface disintegration of the pasta);
• consistency or 'nerve' (resistance to cutting and crushing); and
• clumping (the degree of adhesion of pasta strands/pieces to each other).

Each parameter was evaluated on a scale from 0 to 100 points, allowing for an overall judgment ranging from 'poor' to 'excellent'.

The tests used commercial durum wheat semolina pasta, maintaining the standard ratio of  100 grams of pasta per liter of water. A crucial aspect of the study was the cooking time, using as reference the times indicated by the producer on labels and, in the case of cooking with the heat turned off, for a total time to achieve cooking levels similar to the traditional cooking test. Regarding this, the pasta was cut to examine the thickness of the central starch layers.

Long pasta: promising results for spaghetti

For the  spaghetti, the method with the heat off has shown encouraging results. The experimental technique involves:

• initial cooking at high heat, for two minutes, followed by
• cooking with heat off, with a lid, extending the total time by two minutes compared to that indicated on the package.

The results highlighted a slight qualitative improvement compared to the traditional method, particularly evident in the parameters of  stickiness and clumping. This phenomenon seems due to a ‘washing’ action of the spaghetti surface during the heat-off phase, which transfers a greater amount of starch into the cooking water. This effect was confirmed by the analysis of the sediment, slightly higher in unconventional cooking.

It is important to underline that the diameter of the cooked spaghetti is identical with both methods.

Short pasta, first experiment: substantial modifications needed

The situation becomes complicated with  short pasta shapes, where cooking with the heat off has shown clear limitations. Some preliminary tests have shown that the method proposed by social media, which involves two minutes of cooking with flame followed by cooking with the heat off for a total time equal to the package indication plus 1 minute, is not sufficient.

During pasta cooking, complex phenomena occur: the  gelatinization of starch (optimal between 85-95°C), the modification of gluten proteins, and the denaturation of soluble proteins. These processes compete with each other and influence both the diffusion of water inside the product and the final quality parameters. This explains why the method's limitations become evident when applied to short pastas that have different geometries and surface/volume ratios compared to spaghetti.

It should also be considered that the conventional method, through the kinetic movement of boiling water maintained at an almost constant temperature, allows better heat penetration and continuous stirring action, elements that contribute to the final quality of the product.

Therefore, the unconventional cooking method proposed by social media was modified instead using a flame cooking for 4 minutes and subsequent flame-free cooking with lid for a total time of 5-7 minutes longer than indicated by the manufacturer. Tests were conducted with “smooth penne” format from three different producers.

Despite these precautions, short pasta cooked with the heat off also showed a deterioration in the quality characteristics of the pastas from some producers. Prolonged stay in the container (to achieve cooking levels similar to the conventional system) in fact causes an excessive drop in temperature (down to 75-80°C), moving away from the optimal starch gelatinization range.

Further tests were conducted with the same format of the same three producers by bringing the flame cooking time to 5 and 6 minutes respectively for the second and third producer. This allowed to reduce the overall cooking times and reduce the qualitative differences of the products obtained according to the two cooking methods.

Second experiment and the modified protocol for short pasta

The second experiment was conducted by extending the experiment to different types of smooth and ridged short pasta formats and other national producers in order to verify the validity of the method.

The study identified that the short pastas analyzed can be divided into  three macro groups in relation to the minimum cooking times required over high heat: 4, 5, and 6 minutes. This variability depends on the qualitative characteristics of the raw materials (quantity and quality of proteins, gluten, and starch) and the drying processes adopted by the different producers.

In the case of short pasta, to achieve similar results in terms of cooking quality compared to the conventional system, the study concluded that the experimental cooking protocol must be modified as follows:

• cooking over high heat for 4-6 minutes (instead of 2) with semi-covered pot;
• cooking with heat off, with lid, and  total time extended by 3-5 minutes compared to what is indicated on the package;
• particular attention to stirring operations, to avoid adhesion to the container

The differences between smooth and ridged shapes

An interesting aspect emerged from the research concerns the differences between smooth and ridged pasta. The  smooth penne, due to the characteristics of their surface, present greater criticalities during cooking compared to ridged shapes. Tests with  ridged shapes have indeed shown fewer problems, allowing to minimize undesirable aspects, especially at the organoleptic level.

Conclusions

The study found that  cooking with heat off can improve the quality of long pasta compared to the traditional method, thus representing a valid alternative for formats such as spaghetti, linguine, and similar. For these formats, the proposed method (2 minutes of cooking at high heat + continuation at low heat with lid on until 2 minutes beyond the time indicated on the label) proves effective.

For the  short pasta, instead, the method requires substantial modifications to achieve qualitative characteristics similar to the conventional method: that is, 4-6 minutes of cooking at high heat and a total extension of the cooking time of 3-5 minutes compared to the manufacturer's instructions are necessary.

Research highlights how the qualitative characteristics of raw materials and production processes significantly affect the product's response to cooking at low heat. For the same format, pasta from different producers requires different times and methods, making  impossible a  standardization universal method.

For a conscious application of the technique, consumers should consider the type of short format and identify the different specific cooking times for each brand and format. If they have some familiarity with the pasta brands used at home, this should be quite manageable.

Dario Dongo

Photo by Dotun Abu

Bibliography

• De Lisio, L. (2022). The qualitative evaluation of stickiness, consistency and clumping parameters. Traditional cooking or low-heat cooking of pasta.  Pasta&Pastai, 192, 26-38.