Why can't undercooked rice be cooked again

The reason why undercooked rice is usually not fully cooked is because the starch gelatinization process is irreversible. Rice undercooked is mainly caused by insufficient moisture, uneven heat, imbalanced rice water ratio, premature uncovering, and special rice quality. The formed hard core is difficult to soften through secondary heating.

1. Insufficient water content

Insufficient water content during initial cooking can cause the outer layer of rice grains to gelatinize while the inner layer dehydrates and hardens. At this point, the internal starch molecular structure of the rice grains has changed, and even if water is added and reheated, it is difficult for water to penetrate the dense gelatinization layer and enter the hard core part. When cooking rice with an electric rice cooker, the water level should be about one finger above the rice surface, and traditional steamers need to maintain a continuous steam environment.

2. Uneven firepower

Insufficient local heating during the heating process can cause some rice grains to be in a semi cooked state. Even if the heating time is extended in the later stage, the gelatinized rice grains will continue to dehydrate and harden, while the undercooked parts will be more difficult to ripen due to a decrease in thermal conductivity efficiency. It is recommended to flip it once during cooking, and users of induction cookers should choose a flat bottomed pan to ensure even heating.

III. Imbalance of Rice Water Ratio

The water absorption rate of different varieties of rice can vary by up to 20%. Indica rice usually requires a rice water ratio of 1:1.3, while japonica rice requires a ratio of 1:1.5. The wrong proportion will cause the surface starch to expand excessively and close the pores, and the water supplement in the later stage can only form the surface porridge, which cannot improve the intercalation of the core. New rice needs to reduce its water content by 10% due to its high water content.

4. Premature release after boiling

can cause the water temperature to drop sharply below 95 ℃, interrupting the continuous high temperature environment required for starch gelatinization. At this time, the gel film formed on the outer layer of the rice grain impedes the subsequent heat transfer. Even if the rice grain is covered and boiled again, the steam penetration has been greatly reduced. After the rice cooker trips, it should be simmered for 15 minutes, while the traditional cooking method requires slow steaming over low heat for 20 minutes.

5. Special Rice Quality

Aged or excessively dried rice grains have hardened cell walls, significantly slowing down their water absorption rate. Some imported long grain rice contains special linear starch, which needs to be soaked for 2 hours in advance to fully gelatinize. The undercooked rice produced in such situations can only soften the surface layer to a depth of 1-2 millimeters even when reheated with a pressure cooker.

When encountering sandwiched rice, it can be used as Fried Rice or Congee, and the effect of completely re cooking is limited. To prevent undercooking, fresh rice should be selected, and the amount of water should be adjusted according to the variety. During the cooking process, avoid frequent opening of the lid. When using a smart rice cooker, you can choose the precision cooking mode. For traditional open flame cooking, it is recommended to pair it with a thick bottomed pot and control the medium to low heat. If the phenomenon of undercooked rice often occurs, it is recommended to test the hardness of the water quality at home or change the rice variety.