The Science Behind Rice, Explained

Rice, a staple in countless cuisines worldwide, holds a special place in the culinary traditions of many cultures. Its versatility and adaptability make it a fundamental ingredient that can be transformed into an array of dishes. In Asian cuisine, particularly in countries like China, Japan, and Thailand, rice is a dietary cornerstone. Steamed jasmine rice, sushi rice, and glutinous rice are used as foundations for a wide range of dishes. Sushi and sashimi are incomplete without perfectly seasoned and crafted sushi rice. Thai cuisine, known for its flavorful curries and stir-fries, often features fragrant jasmine rice as the ideal accompaniment. 

India, the world's second-largest producer of rice, boasts a plethora of rice varieties. Basmati and long-grain rice are synonymous with biryanis, pulaos, and other rice-based dishes. In South India, rice takes the form of dosas, idlis, and vadas. It's central to the region's culinary identity. Cookbook, Masala Lab Author, Krish Ahok talks about the science of rice with MasterChef Aruna Vijay, here’s to know more.  


Rice serves as a primary food source for over half of the global population, notably in Asia and Africa. It ranks as the third most cultivated agricultural commodity worldwide, following sugar cane and maize. While sugar cane and maize have non-food applications like alcohol and fuel, rice takes the lead in human nutrition and calorie intake, accounting for over one-fifth of global calorie consumption. Many experts believe rice may have originated in China around 13,000 to 8,000 years ago before spreading to various parts of the world, including India, where it likely arrived in the Gangetic plains about 7,000 years ago. In the growth process, rice undergoes two stages: initially, seedlings are densely cultivated in flooded fields, then transplanted to fields with more spacing. This practice was found to control the height of rice plants, ensuring better seed production and eliminating weeds and pests that cannot thrive in flooded conditions. Over centuries, rice has undergone numerous hybridizations, resulting in modern varieties that are more manageable in size. 

Brown rice, much like other cereal grains, comprises a bran and inedible outer husk, a nutrient-rich bran and germ (the embryonic rice plant), and a starchy endosperm that serves as nourishment for the growing rice plant. When the bran and germ are retained, we obtain brown rice, which is notably rich in micronutrients. It's worth noting that the bran contains fat, which can become rancid over time and is the source of rice bran oil. However, brown rice has a relatively short shelf life, even though it is nutritionally beneficial. It's not feasible to exclusively rely on brown rice to sustain the global population. Consequently, rice has traditionally undergone a polishing process to remove the bran and germ, extending its shelf life and making it a more practical dietary staple. 

Processed or polished rice has a historical context. People long ago recognized that a diet solely composed of polished rice led to various health issues, which were later identified as vitamin deficiencies. Consequently, they discovered a solution: partially boiling the entire rice grain, a process that transferred nutrients from the bran to the endosperm. This yielded parboiled rice, which is significantly more nutritious. In fact, it's noteworthy that a substantial portion of the population who regularly consume rice prefer parboiled rice for its enhanced nutritional value. 

Raw rice is best for special dishes like biryani or pulao. Rice is mostly made of starch, and there are two types: amylose, which is firmer, and amylopectin, which is stickier. Rice with more amylose is firm, while more amylopectin makes it soft and sticky. Amylose is harder to digest. In India, specific rice varieties are preferred. For instance, basmati, Sonamasuri, and Gobindbhog have higher amylose content. The differences in amylose and amylopectin ratios mainly affect the texture and flavour, making them suitable for different cuisines and dishes. 


The first thing we do with rice is wash and rinse it. Some people think this is to remove starch, but it's not very effective for that. Even if you rinse rice, you won't remove many calories. For instance, if you rinse 100 grams of rice, you might remove just a few grams. So, it's not necessary for all dishes. Rice might be a bit stickier if you don't rinse it, which is fine for South Indian dishes. However, if you're making biryani or pulao, rinsing a few times can prevent the rice from sticking. Another good reason to rinse is to remove any chemicals that might be on the rice from the polishing process. 


Soaking rice in water is a choice depending on your dish. It helps the rice absorb some water, and this happens when you heat it later. This is more crucial for dishes like biryani or pulao, where soaking for 20 to 30 minutes is enough. Estimating the right amount of water for cooking rice can be tricky. A simple method is using a one-to-one ratio by volume, where you add enough water to cover the rice. Then, for open pots or electric rice cookers, you add extra water to reach the first joint of your index finger, which is a good starting point. 

In some Indian villages and for biryani, there's a different method. You add extra water without worrying about the amount. The key here is to make the water taste as salty as the sea. This might seem like a lot of salt, but not all of it will be absorbed by the rice. Then, you cook the rice until it's almost but not fully done, leaving it slightly firm. You can also add spices and a bit of fat to the water for extra flavours, then drain the excess water and use the rice for layering in your biryani. 

Myths Debunked 

Is rice healthy?  

Rice is mainly made up of carbohydrates, and we often eat polished rice, which lacks some important nutrients like protein and healthy fats. Diets high in grains, whether it's rice, wheat, or millets, aren't very healthy. However, rice is a crucial source of carbs in South and East India, as well as in East and Southeast Asia. Instead of just focusing on rice, it's better to think about your entire meal. A healthy meal includes a moderate amount of rice along with lots of vegetables, some protein, and not too much fat. Rice can be a part of a balanced diet. 

Does washing and rinsing rice reduce calories, removing the starch? 

When it comes to different rice types like Basmati, Sonamasoori, or Govindbhog, there aren't significant differences in nutrition. Rice itself doesn't have a lot of micronutrients, but the way it's processed can make a difference. Brown or red rice contains more bran, which has more micronutrients. However, it has a short shelf life, and there's concern about arsenic, which can be found in the soil. Parboiled rice is a good compromise, as it has more vitamins compared to polished raw rice. It's a good idea to make parboiled rice your regular choice and use raw rice for special dishes like biryani. 

Are there health and nutritional benefits in different rice varieties? Why did he feel sleepy after eating rice?  

When you eat rice, it's a carbohydrate that's easily digested. About 30 minutes after consuming rice, a lot of glucose enters your bloodstream from the small intestine. Your pancreas then releases insulin to lower your blood sugar, mostly by converting it into fat. This process causes your blood sugar to drop, sending a signal to your brain that you need rest, making you feel sleepy. 

This is why modern medicine advises against consuming excessive rice because it can lead to rapid spikes and crashes in blood sugar, which our bodies can't handle well. To avoid feeling drowsy after a meal, it's better to eat a moderate amount of rice along with plenty of vegetables, protein, and some fat. This combination causes a more gradual rise and fall in blood sugar, helping you stay awake and alert. 

Is it true that cold, overnight refrigerated rice has fewer calories?  

In reality, this is one of the rare instances where viral content on the internet is true. Here's why: When you cook rice, the starch in it absorbs water and expands. As it cools down to room temperature, it hardens and forms crystals, a process called retrogradation. This is why rice left out for a while becomes hard. Retrograded starch is harder to digest, and that's a positive thing. We don't want fast digestion, which leads to spikes and crashes in blood glucose levels. So, if you're someone who consumes a lot of rice, refrigerating it overnight causes more retrogradation and is a good choice for better health.