You can’t truly remove carbohydrates from rice, since starch makes up roughly 80% of its dry weight. But you can change how your body digests that starch, effectively lowering the calories and blood sugar impact of every serving. The most proven technique involves cooking rice with a small amount of fat, cooling it for 12 hours, and reheating it. Combined with a few other strategies, you can cut the available carbohydrates in rice by a meaningful amount without giving it up entirely.
Why Cooling Rice Changes Its Carbs
When rice cools after cooking, a process called retrogradation rearranges its starch molecules. The starch chains lock together into tight double-helix structures that squeeze out water. Once they’ve reformed this way, your digestive enzymes can no longer break them down efficiently. The result is “resistant starch,” a type of carbohydrate that passes through your small intestine mostly undigested, behaving more like fiber than like sugar.
This matters because digestible starch is what spikes your blood sugar after a bowl of rice. Converting even a portion of that starch into resistant starch means fewer calories absorbed and a gentler blood sugar curve. The conversion isn’t complete, so you’re not eliminating carbs, but you are making a real dent in how much of the rice your body treats as fuel.
The Coconut Oil and Cooling Method
The most widely cited technique comes from researchers at the College of Chemical Sciences in Sri Lanka, who presented their findings at an American Chemical Society meeting. Their protocol is simple:
- Add fat before cooking. Bring water to a boil and add one teaspoon of coconut oil per half cup of dry rice.
- Cook normally. Simmer for about 40 minutes, or boil for 20 to 25 minutes, whichever suits your setup.
- Refrigerate for 12 hours. Transfer the cooked rice to the fridge and leave it overnight.
- Reheat and eat. Warming it back up doesn’t reverse the resistant starch formation.
The fat plays a specific role here. During cooking, oil molecules enter the starch granules and form complexes that resist digestion. Cooling then locks additional starch into those tight, enzyme-resistant structures. The researchers found that with the right rice variety, this process could reduce available calories by 50 to 60 percent. Even with ordinary rice, the reduction is significant enough to be worth the overnight wait.
You can use other cooking fats if coconut oil isn’t your preference. The key mechanism is a fat molecule binding with starch during the cooking process, so butter or olive oil should produce a similar, if possibly slightly smaller, effect.
Reheating Won’t Undo the Effect
One of the most practical details about this method is that resistant starch, once formed, stays resistant even when you microwave or pan-fry the rice the next day. The double-helix structures created during cooling are thermally stable enough to survive normal reheating temperatures. So you can meal-prep a batch of rice on Sunday, refrigerate it, and reheat portions throughout the week without losing the benefit.
Choosing a Lower-Impact Rice Variety
Not all rice starts with the same starch profile. Long-grain varieties like basmati and jasmine contain more amylose, the type of starch molecule most likely to form resistant starch during cooling. Short-grain and sticky rice varieties are higher in amylopectin, which retrogrades less efficiently.
Parboiled rice offers another advantage. Parboiling involves steaming the grain in its husk before milling, which partially pre-gelatinizes the starch and changes its structure. In a study of nine people with type 2 diabetes, severely parboiled rice had a glycemic index of 39, compared to 55 for non-parboiled rice of the same variety. That’s nearly a 30% reduction in blood sugar impact, and it comes before you even apply the cooling technique. Combining parboiled rice with the coconut oil method could stack both effects.
Rinsing and Draining: Limited but Real
Rinsing rice before cooking washes away loose surface starch, which is why rinsed rice cooks up less sticky. However, the carbohydrate reduction from rinsing alone is minimal. Most of the starch is locked inside the grain, not sitting on the surface. What rinsing does remove is enriched nutrients: iron, folate, thiamin, and niacin all wash off polished and parboiled rice during rinsing. If you’re rinsing primarily for texture, that’s fine, but don’t expect it to meaningfully lower your carb intake.
Cooking rice in a large volume of water and then draining it (the way you’d cook pasta) does pull more starch into the water. This approach removes somewhat more carbohydrate than the standard absorption method, but it also strips the same B-vitamins and minerals. If you’re using enriched rice and relying on it for micronutrients, the trade-off may not be worth it.
Safe Cooling Practices
Cooked rice is one of the more common sources of food poisoning because a bacterium called Bacillus cereus thrives in starchy foods left at warm temperatures. USDA guidelines are specific: cooked food should not sit at room temperature for more than two hours. Cool rice from cooking temperature down to 70°F within two hours, and get it below 41°F within six hours total. The simplest approach is to spread the rice in a thin layer on a sheet pan so it cools quickly, then transfer it to the refrigerator.
If you’re doing the 12-hour cooling method, put the rice in the fridge as soon as it stops steaming. Don’t leave it on the counter overnight. Proper refrigeration keeps the rice safely below 41°F the entire time the resistant starch is forming.
Low-Carb Rice Substitutes
If you want to go further than reducing available carbs, partial or full substitution is the most effective route. Konjac rice, made from the root of the konjac plant, contains just 1 gram of carbohydrate per 100-gram serving, compared to 28 grams in the same amount of white rice. It’s mostly water and a soluble fiber called glucomannan, so the texture is different, but it works well mixed into dishes with strong sauces or seasonings.
Cauliflower rice, made by pulsing raw cauliflower in a food processor, runs about 3 to 5 grams of carbs per 100-gram serving. It won’t fool anyone into thinking it’s actual rice, but it absorbs flavors well and works in stir-fries, grain bowls, and fried rice preparations. A common middle-ground approach is mixing half cauliflower rice with half cooled-and-reheated white rice, cutting your effective carb load roughly in half while keeping a more familiar texture.
Putting It All Together
The biggest single reduction comes from the cook-cool-reheat cycle with added fat. Start with a high-amylose or parboiled variety, cook it with a teaspoon of coconut oil, refrigerate it for 12 hours, and reheat before eating. If you want to push further, mix in a portion of konjac or cauliflower rice. Each of these strategies chips away at the available carbohydrate from a different angle, and they’re all compatible with each other.
None of these methods will turn rice into a zero-carb food. A half cup of cooled and reheated rice still contains a meaningful amount of carbohydrate. But for people managing blood sugar or trying to reduce their carb intake without abandoning a staple food, the difference between freshly cooked rice and properly cooled rice is large enough to matter at every meal.