How To Cook “Perfect” Short Grain Rice Using A Little Help From Science
This recipe is for white short grain, or Japonica Rice, aka: Japanese rice, sushi rice.
Summary - What to do
Measure by weight, not by volume, or never a finger for water
Use best tasting water available to rinse and cook
Soak the rice for 120 min at 5℃
Water ratio: 1:1.1
Keep the internal temperature of 98℃/208.4°F for 20 minutes
Summary - What to avoid
Measure by volume, or using your finger to measure water
Cooking without a lid
Remove the lid while cooking or steaming rice
Throw short grain white rice into boiling water
Cook short grain white rice without soaking in water
Since I started to teach an online sushi making class in August 2020, my class attendees need to make sushi rice before the class starts. I've noticed some were successful, but the majority of them told me their rice did not come our "right," or cooking rice was "so difficult."
This is a new experience for me. For the in-person class I've been teaching for over ten years, we provided cooked sushi rice. Our class attendees did not have to cook rice during the class (because it would make the class too long.) I knew sushi rice was a mystery to some, but I never guessed there are so many.
This led me to examine online recipes for "how to cook sushi rice."
After reading dozens and over twenty youtube videos (I listed some of them in the glossary section), I've noticed some problems.
It's not that all of the recipes are wrong, but most of them fail to mention some critical issues that would lead to your rice being cooked "not appropriate."
Because I liked the reasoning behind recipes and cooking techniques, I have included as much scientific explanation as possible.
I hope this will help you to make sense of the mystery in cooking rice.
Why is it so difficult to cook “perfect” rice?
There is no one size fits all recipe.
There are 120,000 rice varieties in the world (source: Rice USA). Each rice has different starch, moisture content, shape and size, which affect the amount of rice required and time you need to cook.
When we see the "how to cook rice" recipe online, it says "rice" and I believe many think they can use the recipe for "All the rice" thinking rice is the rice, right?
When cooking rice, you need to find a recipe specific to your rice variety, such as short grain white rice, basmati rice, etc. This is the very first mistake many people make (I am guessing here tough.)
Precise measurement is the basis of any cooking
Cooking rice is a precise chemical reaction. A precise chemical reaction requires precise measuring.
When measuring rice, use a scale and measure by the weight, not by the volume.
Measuring by weight is always more accurate.
Here is an example.
I have two containers of white short grain rice - each measuring 400 ml.
When you weigh both, one is 495g and the other is 500g, a 5g of difference. That is 1% of the difference, but when you double or triple the recipe, the difference will be enough to call for the adjustment in the recipe.
This is why the finger method to measure the water is not such a great idea, though, used properly, it could work.
But for now, especially if you are a beginner, measuring by weight is the best approach.
The quality of water you use to wash and cook is just as important
Roughly 75% of cooked rice is water. So, it makes sense to use the best tasting water possible to cook, but why am I recommending using the best tasting (filtered, spring, or mineral) water to rinse your rice?
When you rise the uncooked rice for the first time, it will soak up the most water, which is what you will taste when rice is cooked. Thus, it's in your best interest to use the best tasting water.
Should I rise the white short grain rice?
Rinsing rice removes the starch and any debris like sand from the rice. Does it affect the taste of your rice? Well, that really depends on the "brand" of rice you use.
I've used Lundberg Sushi Rice, Nishiki, Calrose, and Kokuho rice (they are white short and medium grain rice.)
I have noticed some differences in taste when rice is rinsed and not rinsed. Unrised rice, not always, but sometimes came out starchier.
Many youtube videos and recipes say rice refining machines have been making progress, so you may not have to rinse the rice before cooking.
My answer is it may not make the dramatic difference, but, if you are sensitive (meaning type of person who can taste the difference), then, by all means, rise the rise before cooking.
It’s not about how much water you need, it’s how much water you lose
The second reason the recipe you saw didn’t work is all of them talk about how much water you need to cook “perfect” rice.
This is backward.
No matter what varieties of rice – short, basmati, brown – they always end up soaking the same amount of rice, 1:1 ratio, meaning 1 cup of uncooked rice soaks 1 cup of water. No more (Cooks Illustrated: The Secrets of Cooking Rice.)
Then, why all the recipes call for a different amount of water to cook rice, like "For brown rice, the ratio is 1:3 and white rice, it's 1:1.5, etc.?"
The reason is that water evaporates during cooking.
Simply put, cooking rice is: To transfer the same ratio of water into uncooked rice using heat. But, depending on the type of container you use – a pot, a pot with a lid, a lid with a hole, and so on – the amount of water you lose during the cooking will be different.
Cooking time also affects the amount of water being observed in the rice. This is why it’s hard to cook rice using a pot using someone else's recipe.
Your pot is different from the one used by the person who wrote the recipe. Therefore, the amount of water you lose when cooking rice will be different.
The only way for you to find out how much water you need is trial and error.
This is why I recommend using a rice cooker, which provides the same cooking “environment” every time, meaning the water loss ratio is always the same.
This is another reason why doubling the recipe never works because the amount of water loss does not double just because you double the rice and water in a pot.
The chemical reaction of cooking rice
Starch in rice is partially crystallized when uncooked. Cooking rice is a chemical process called gelatinization - a chemical process during which the starch granules absorb a bunch of water and lose their crystallinity.
There is a second chemical reaction called pasting – a process in which starch like amylose leach out the rice, increasing the viscosity of the liquid surrounding rice. This is the reason porridge gets a creamy texture. (Science meets food)
What happens when you put rice into boiling water?
The heat penetrates to the outer layer only, but not the dry inner layer, leaving the inside of rice undercooked. To cook unsoaked rice thoroughly, you end up overcooking the outer layer, resulting in pasting, creamy texture. If your rice ever ended up being this way, it could be because you skipped soaking and put rice in boiling water.
This is also the reason you should never cook unsoaked rice, especially white short grain rice. Always soak white short grain rice in water before cooking. The question you may be wondering is how long and what temperature?
The optimal soaking time is 120min at 5℃
When a soaking time is short, white short grain rice will be hard. The longer the soaking time is, the softer(gooey) and tender the white short grain rice will become. According to Naoki Higuchi of TravelingFoodLab, 120min at 5℃ resulted in the best tasting taste and texture.
The ideal cooking time is 20 minutes at 98℃/208.4°F.
Based on the test performed by the professors at Hiroshima Bunka Gakuen University, the temperature of 98℃ for 20 minutes is the energy required to cook white short grain rice properly.
But if you keep the heat on for 20 minutes at 98℃, the bottom of the white short grain rice will get burnt (unless you have enough water in the pot.)
Therefore, after the water starts to boil (100℃), keep the low heat for 10 minutes or so until the water evaporates, and turn the heat off. To keep the internal temperature above 98℃, you must keep the lid on.
Cook in a pot without a lid with low heat
Another technique I’ve seen is to start cooking rice in a pot with low heat. You need to bring the water to boiling point in the first 8 to 15 minutes. When taking longer, pasting will occur, making it a porridge like texture. So, it’s important to heat up the water as quickly as possible so the rice will have a nice soft texture but not slimy.
Once the water starts boiling, remove the lid, and stir throughout.
Some starch gets stuck in the bottom of the pot. Stirring will help even heat transfer of the pot. Make sure to avoid over stirring. You will break the granules resulting in pasting.
After stirring, place the lid back on quickly to keep the temperature.
When it starts to boil again, lower the heat, cook for ten minutes. During this time, rice is observing water.
Steaming is to release excess water
After cooking for ten minutes, now it’s time to steam. Turn the heat off. Keep the lid because you need to keep the minimum internal temperature of at least 98℃. During this time, rice will release excess moisture to soak up 1:1 ratio water, making it the “perfect” rice.
White short grain rice or US grown medium grain “Japanese” rice, rice labels as Sushi Rice, 400g
Water (filtered, Bottled spring/mineral water preferred) to cook, 440g
Pot with a lid
Measure the rice and water using a scale.
In a bowl, pour water. Place rice in a strainer, and soak it in the bowl. Remove the strainer with rice from the water. Discard the water.
Repeat the previous step.
Pour water again, place the rice in a bowl, using the hands, gently rub for a few times. Drain.
Repeat the previous step.
Transfer the rice into a pot. Pour 440g water, store in the fridge for 120 min.
Place the pot with a lid.
High heat until the water starts to boil
Remove the lid, stir gently, two to three times
Turn the heat to low, place the lid
Cook for ten minutes or until all the water evaporates in a pot
Turn the heat off
Keep the lid on, steam for 10 minutes
Remove the lid, using a spatula or a large spoon, stir the rice gently
*May need to adjust the amount of water depending on the pot or rice cooker
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